Constantinos Mylonas

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2024

Katirtzoglou, Aikaterini; Tsaparis, Dimitris; Kolios, Evangelos; Magoulas, Antonios; Mylonas, Constantinos C; Fakriadis, Ioannis; Manousaki, Tereza; Tsigenopoulos, Costas S

Population genomic analysis of the greater amberjack (Seriola dumerili) in the Mediterranean and the Northeast Atlantic, based on SNPs, microsatellites, and mitochondrial DNA sequences Journal Article

Frontiers in Fish Science, 2 , pp. 1356313, 2024, ISSN: 2813-9097.

Abstract | Links | BibTeX

@article{katirtzoglou_population_2024,
title = {Population genomic analysis of the greater amberjack (\textit{Seriola dumerili}) in the Mediterranean and the Northeast Atlantic, based on SNPs, microsatellites, and mitochondrial DNA sequences},
author = {Aikaterini Katirtzoglou and Dimitris Tsaparis and Evangelos Kolios and Antonios Magoulas and Constantinos C Mylonas and Ioannis Fakriadis and Tereza Manousaki and Costas S Tsigenopoulos},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2024/03/2024-Kaitirtzoglou-frish-14.pdf
https://www.frontiersin.org/articles/10.3389/frish.2024.1356313/full},
doi = {10.3389/frish.2024.1356313},
issn = {2813-9097},
year = {2024},
date = {2024-03-14},
urldate = {2024-03-14},
journal = {Frontiers in Fish Science},
volume = {2},
pages = {1356313},
abstract = {The greater amberjack (
Seriola dumerili
) has attracted considerable economic interest since the 1990s because it possesses traits that distinguish it as a promising candidate in aquaculture. However, the challenges of its successful rearing, combined with the need to develop proper management practices, underline the importance of research into the genetic diversity of both wild and farmed stocks. We aimed to decipher the genetic structure of
S. dumerili
in the Eastern Mediterranean and the Northeast Atlantic using three types of genetic markers (mitochondrial control region sequences, microsatellites, and single nucleotide polymorphisms, or SNPs) to evaluate the population genetic structure of the species. The results were compared to those of previous studies of the species focusing on the Central Mediterranean and confirmed the presence of two divergent mtDNA haplogroups distributed without any detectable geographical structuring within the Mediterranean and the Atlantic. However, population analyses of the genetic structure of the species using either 10 microsatellites or a set of 1,051 SNP markers suggest that the species forms three genetically distinct groups, one in the Mediterranean and two in the Atlantic. The latter has so far not been reported in the Northeast Atlantic, and that this differentiation refers to samples from the Canary Islands is surprising. Fifteen candidate outlier SNP loci were identified in the data set, one located within the
tead1a
/TEF-1A gene, which has been associated with temperature acclimation of the medaka. This work enriches our knowledge of the genetic diversity of wild populations of the greater amberjack in the Mediterranean and the Northeast Atlantic and attempts to investigate signs of local adaptation toward a better understanding of the species distribution patterns. Future studies should be conducted to investigate the genomic regions associated with temperature acclimation in marine organisms that have to adapt to the ongoing climate change pressures, such as sea temperature rise, in order to survive.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The greater amberjack (
Seriola dumerili
) has attracted considerable economic interest since the 1990s because it possesses traits that distinguish it as a promising candidate in aquaculture. However, the challenges of its successful rearing, combined with the need to develop proper management practices, underline the importance of research into the genetic diversity of both wild and farmed stocks. We aimed to decipher the genetic structure of
S. dumerili
in the Eastern Mediterranean and the Northeast Atlantic using three types of genetic markers (mitochondrial control region sequences, microsatellites, and single nucleotide polymorphisms, or SNPs) to evaluate the population genetic structure of the species. The results were compared to those of previous studies of the species focusing on the Central Mediterranean and confirmed the presence of two divergent mtDNA haplogroups distributed without any detectable geographical structuring within the Mediterranean and the Atlantic. However, population analyses of the genetic structure of the species using either 10 microsatellites or a set of 1,051 SNP markers suggest that the species forms three genetically distinct groups, one in the Mediterranean and two in the Atlantic. The latter has so far not been reported in the Northeast Atlantic, and that this differentiation refers to samples from the Canary Islands is surprising. Fifteen candidate outlier SNP loci were identified in the data set, one located within the
tead1a
/TEF-1A gene, which has been associated with temperature acclimation of the medaka. This work enriches our knowledge of the genetic diversity of wild populations of the greater amberjack in the Mediterranean and the Northeast Atlantic and attempts to investigate signs of local adaptation toward a better understanding of the species distribution patterns. Future studies should be conducted to investigate the genomic regions associated with temperature acclimation in marine organisms that have to adapt to the ongoing climate change pressures, such as sea temperature rise, in order to survive.

Fakriadis, Ioannis; Meiri-Ashkenazi, Iris; Bracha, Chen; Rosenfeld, Hanna; Corriero, Aldo; Zupa, Rosa; Pousis, Chrysovalentinos; Papadaki, Maria; Mylonas, Constantinos C

Gonadotropin expression, pituitary and plasma levels in the reproductive cycle of wild and captive-reared greater amberjack (Seriola dumerili) Journal Article

General and Comparative Endocrinology, 350 , pp. 114465, 2024, ISSN: 00166480.

Links | BibTeX

Ventriglia, G; Fakriadis, I; Papadaki, M; Zupa, R; Pousis, C; Mandalakis, M; Corriero, A; Mylonas, C C

Effects of different hormonal treatments on spermatogenesis advancement in hatchery-produced greater amberjack Seriola dumerili (Risso 1810) Journal Article

348 , pp. 114447, 2024, ISSN: 00166480.

Links | BibTeX

Lancerotto, Stefano; Fakriadis, Ioannis; Papadaki, Maria; Mandalakis, Manolis; Sigelaki, Irini; Mylonas, Constantinos C

Timing of puberty in F1-generation hatchery-produced greater amberjack (Seriola dumerili) Journal Article

General and Comparative Endocrinology, 347 , pp. 114414, 2024, ISSN: 00166480.

Links | BibTeX

2023

Lavecchia, Anna; Manzari, Caterina; Pousis, Chrysovalentinos; Mansi, Luigi; Cox, Sharon N; Mylonas, Constantinos C; Zupa, Rosa; Giudice, Claudio Lo; Virgilio, Caterina De; Picardi, Ernesto; Ventriglia, Gianluca; Pesole, Graziano; Corriero, Aldo

Dysregulation of testis mRNA expression levels in hatchery-produced vs wild greater amberjack Seriola dumerili Journal Article

Scientific Reports, 13 (1), pp. 13662, 2023, ISSN: 2045-2322.

Abstract | Links | BibTeX

@article{lavecchia_dysregulation_2023,
title = {Dysregulation of testis mRNA expression levels in hatchery-produced vs wild greater amberjack Seriola dumerili},
author = {Anna Lavecchia and Caterina Manzari and Chrysovalentinos Pousis and Luigi Mansi and Sharon N Cox and Constantinos C Mylonas and Rosa Zupa and Claudio Lo Giudice and Caterina De Virgilio and Ernesto Picardi and Gianluca Ventriglia and Graziano Pesole and Aldo Corriero},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/08/2023-Lavecchia-SciRep-42.pdf
https://www.nature.com/articles/s41598-023-40597-5},
doi = {10.1038/s41598-023-40597-5},
issn = {2045-2322},
year = {2023},
date = {2023-08-28},
urldate = {2023-08-29},
journal = {Scientific Reports},
volume = {13},
number = {1},
pages = {13662},
abstract = {Abstract

Reproductive dysfunctions have been recently documented in male greater amberjack
Seriola dumerili
caught from the wild and reared in captivity. In the present study, we compared testis transcriptome in wild fish (WILD), hatchery-produced fish with apparently normal spermatogenesis (Normal Farmed; NormalF) and hatchery-produced fish with evident reproductive dysfunction (Dysfunctional Farmed; DysF). Gene expression analysis identified 2157, 1985 and 74 differentially expressed genes (DEGs) in DysF
vs
WILD, NormalF
vs
DysF and NormalF
vs
WILD comparisons, respectively. In DysF, a dysregulation of several interconnected biological processes, including
cell assembly
,
steroidogenesis
and
apoptosis
was found. Gene enrichment of
progesterone-mediated oocyte maturation
,
oocyte meiosis
and
cell cycle
pathways were identified in the DysF
vs
NormalF comparison. Most of the DEGs involved in the enriched pathways were downregulated in DysF. The comparison of NormalF
vs
WILD showed that most of the DEGs were downregulated in NormalF, including a gene that encodes for a regulatory protein with a protective role in apoptosis regulation (
ptpn
6), indicating that spermatogenesis was dysfunctional also in the apparently “normal” hatchery-produced fish. Hence, rearing of male greater amberjack in captivity, from eggs produced by captive breeders, did not prevent the appearance of reproductive dysfunctions, and these dysfunctions involved several biological processes and metabolic pathways.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Panteli, Nikolas; Feidantsis, Konstantinos; Demertzioglou, Maria; Paralika, Vasiliki; Karapanagiotis, Stelios; Mylonas, Constantinos C; Kormas, Konstantinos Ar.; Mente, Eleni; Makridis, Pavlos; Antonopoulou, Efthimia

The Probiotic Phaeobacter inhibens Provokes Hypertrophic Growth via Activation of the IGF-1/Akt Pathway during the Process of Metamorphosis of Greater Amberjack (Seriola dumerili, Risso 1810) Journal Article

Animals, 13 (13), pp. 2154, 2023, ISSN: 2076-2615.

Abstract | Links | BibTeX

@article{panteli_probiotic_2023,
title = {The Probiotic Phaeobacter inhibens Provokes Hypertrophic Growth via Activation of the IGF-1/Akt Pathway during the Process of Metamorphosis of Greater Amberjack (Seriola dumerili, Risso 1810)},
author = {Nikolas Panteli and Konstantinos Feidantsis and Maria Demertzioglou and Vasiliki Paralika and Stelios Karapanagiotis and Constantinos C Mylonas and Konstantinos Ar. Kormas and Eleni Mente and Pavlos Makridis and Efthimia Antonopoulou},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/07/2023-Panteli-Animals-36.pdf
https://www.mdpi.com/2076-2615/13/13/2154},
doi = {10.3390/ani13132154},
issn = {2076-2615},
year = {2023},
date = {2023-07-07},
urldate = {2023-07-07},
journal = {Animals},
volume = {13},
number = {13},
pages = {2154},
abstract = {Metamorphosis entails hormonally regulated morphological and physiological changes requiring high energy levels. Probiotics as feed supplements generate ameliorative effects on host nutrient digestion and absorption. Thereby, the aim of the present research was to investigate the impact of the probiotic Phaeobacter inhibens as a water additive on cellular signaling pathways in the metamorphosis of greater amberjack (Seriola dumerili). Activation of insulin-like growth factor type 1 receptor (IGF-1R), protein kinase B (Akt), mitogen-activated protein kinases (MAPKs) and AMP-activated protein kinase (AMPK), induction of heat shock proteins (Hsps), and programmed cell death were assessed through SDS-Page/immunoblot analysis, while energy metabolism was determined through enzymatic activities. According to the results, greater amberjack reared in P. inhibens-enriched water entered the metamorphic phase with greater body length, while protein synthesis was triggered to facilitate the hypertrophic growth as indicated by IGF-1/Akt activation and AMPK inhibition. Contrarily, MAPKs levels were reduced, whereas variations in Hsps response were evident in the probiotic treatment. Apoptosis and autophagy were mobilized potentially for the structural remodeling processes. Furthermore, the elevated enzymatic activities of intermediary metabolism highlighted the excess energy demands of metamorphosis. Collectively, the present findings demonstrate that P. inhibens may reinforce nutrient utilization, thus leading greater amberjack to an advanced growth and developmental state.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Papadogiannis, Vasileios; Manousaki, Tereza; Nousias, Orestis; Tsakogiannis, Alexandros; Kristoffersen, Jon B; Mylonas, Constantinos C; Batargias, Costas; Chatziplis, Dimitrios; Tsigenopoulos, Costas S

Chromosome genome assembly for the meagre, Argyrosomus regius, reveals species adaptations and sciaenid sex-related locus evolution Journal Article

Frontiers in Genetics, 13 , pp. 1081760, 2023, ISSN: 1664-8021.

Abstract | Links | BibTeX

@article{papadogiannis_chromosome_2023b,
title = {Chromosome genome assembly for the meagre, Argyrosomus regius, reveals species adaptations and sciaenid sex-related locus evolution},
author = {Vasileios Papadogiannis and Tereza Manousaki and Orestis Nousias and Alexandros Tsakogiannis and Jon B Kristoffersen and Constantinos C Mylonas and Costas Batargias and Dimitrios Chatziplis and Costas S Tsigenopoulos},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/07/2023-Papadogiannis-FrontGen-34.pdf
https://www.frontiersin.org/articles/10.3389/fgene.2022.1081760/full},
doi = {10.3389/fgene.2022.1081760},
issn = {1664-8021},
year = {2023},
date = {2023-07-03},
urldate = {2023-07-03},
journal = {Frontiers in Genetics},
volume = {13},
pages = {1081760},
abstract = {The meagre,
Argyrosomus regius
, has recently become a species of increasing economic interest for the Mediterranean aquaculture and there is ongoing work to boost production efficiency through selective breeding. Access to the complete genomic sequence will provide an essential resource for studying quantitative trait-associated loci and exploring the genetic diversity of different wild populations and aquaculture stocks in more detail. Here, we present the first complete genome for
A. regius , produced through a combination of long and short read technologies and an efficient in-house developed pipeline for assembly and polishing. Scaffolding using previous linkage map data allowed us to reconstruct a chromosome level assembly with high completeness, complemented with gene annotation and repeat masking. The 696 Mb long assembly has an N50 = 27.87 Mb and an L50 = 12, with 92.85% of its length placed in 24 chromosomes. We use this new resource to study the evolution of the meagre genome and other Sciaenids,
via
a comparative analysis of 25 high-quality teleost genomes. Combining a rigorous investigation of gene duplications with base-wise conservation analysis, we identify candidate loci related to immune, fat metabolism and growth adaptations in the meagre. Following phylogenomic reconstruction, we show highly conserved synteny within Sciaenidae. In contrast, we report rapidly evolving syntenic rearrangements and gene copy changes in the sex-related
dmrt1
neighbourhood in meagre and other members of the family. These novel genomic datasets and findings will add important new tools for aquaculture studies and greatly facilitate husbandry and breeding work in the species.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Zupa, Rosa; Duncan, Neil; Giménez, Ignacio; Mylonas, Constantinos C; Pousis, Chrysovalentinos; Passantino, Letizia; Cuko, Rezart; Corriero, Aldo

Male germ cell proliferation and apoptosis in sexually immature meagre Argyrosomus regius (Asso, 1801) treated with recombinant follicle stimulating hormone Journal Article

Scientific Reports, 13 (1), pp. 7013, 2023, ISSN: 2045-2322.

Abstract | Links | BibTeX

@article{zupa_male_2023,
title = {Male germ cell proliferation and apoptosis in sexually immature meagre Argyrosomus regius (Asso, 1801) treated with recombinant follicle stimulating hormone},
author = {Rosa Zupa and Neil Duncan and Ignacio Giménez and Constantinos C Mylonas and Chrysovalentinos Pousis and Letizia Passantino and Rezart Cuko and Aldo Corriero},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/06/2023-Zupa-Sci-Reports-29.pdf
https://www.nature.com/articles/s41598-023-34102-1},
doi = {10.1038/s41598-023-34102-1},
issn = {2045-2322},
year = {2023},
date = {2023-06-09},
urldate = {2023-06-13},
journal = {Scientific Reports},
volume = {13},
number = {1},
pages = {7013},
abstract = {The meagre Argyrosomus regius (Asso, 1801) is a marine fish species that has an increasing aquaculture production in Europe. Lowering the age at maturity of hatchery-produced juveniles would support meagre aquaculture by reducing time between generations in selective breeding programs and reducing industrial costs for broodstock maintenance. The aim of this work was to assess the effects of a treatment with recombinant follicle stimulating hormone (rFsh), produced in ovarian cells of Chinese hamsters, on male germ cell proliferation and apoptosis in sexually immature meagre. The rFsh-treated fish had higher gonadosomatic index, larger seminiferous tubules, more abundant luminal spermatozoa, a lower density of anti-PCNA positive single A spermatogonia, a higher density of anti-PCNA positive spermatocysts and a lower incidence of germ cell apoptosis than control groups. The present study demonstrated the effectiveness of the produced rFsh in stimulating testis development and spermatogenesis in pre-pubertal meagre. Moreover, the rFsh treatment proved to be highly efficient in removing the apoptotic block of spermatogenesis observed in juvenile meagre, allowing spermatogonial survival and progress towards meiosis. The administration of rFsh did not stimulate spermatogonial self-renewal, a process whose control still needs to be elucidated.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Chromosome genome assembly for the meagre, Argyrosomus regius, reveals species adaptations and sciaenid sex-related locus evolution Journal Article

Frontiers in Genetics, 13 , pp. 1081760, 2023, ISSN: 1664-8021.

Abstract | Links | BibTeX

@article{papadogiannis_chromosome_2023,
title = {Chromosome genome assembly for the meagre, Argyrosomus regius, reveals species adaptations and sciaenid sex-related locus evolution},
author = {Vasileios Papadogiannis and Tereza Manousaki and Orestis Nousias and Alexandros Tsakogiannis and Jon B Kristoffersen and Constantinos C Mylonas and Costas Batargias and Dimitrios Chatziplis and Costas S Tsigenopoulos},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/01/2023-Papadogiannis-FinGenetics-4.pdf
https://www.frontiersin.org/articles/10.3389/fgene.2022.1081760/full},
doi = {10.3389/fgene.2022.1081760},
issn = {1664-8021},
year = {2023},
date = {2023-01-10},
urldate = {2023-01-11},
journal = {Frontiers in Genetics},
volume = {13},
pages = {1081760},
abstract = {The meagre,
Argyrosomus regius
, has recently become a species of increasing economic interest for the Mediterranean aquaculture and there is ongoing work to boost production efficiency through selective breeding. Access to the complete genomic sequence will provide an essential resource for studying quantitative trait-associated loci and exploring the genetic diversity of different wild populations and aquaculture stocks in more detail. Here, we present the first complete genome for
A. regius , produced through a combination of long and short read technologies and an efficient in-house developed pipeline for assembly and polishing. Scaffolding using previous linkage map data allowed us to reconstruct a chromosome level assembly with high completeness, complemented with gene annotation and repeat masking. The 696 Mb long assembly has an N50 = 27.87 Mb and an L50 = 12, with 92.85% of its length placed in 24 chromosomes. We use this new resource to study the evolution of the meagre genome and other Sciaenids,
via
a comparative analysis of 25 high-quality teleost genomes. Combining a rigorous investigation of gene duplications with base-wise conservation analysis, we identify candidate loci related to immune, fat metabolism and growth adaptations in the meagre. Following phylogenomic reconstruction, we show highly conserved synteny within Sciaenidae. In contrast, we report rapidly evolving syntenic rearrangements and gene copy changes in the sex-related
dmrt1
neighbourhood in meagre and other members of the family. These novel genomic datasets and findings will add important new tools for aquaculture studies and greatly facilitate husbandry and breeding work in the species.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2022

Panteli, Nikolas; Demertzioglou, Maria; Feidantsis, Konstantinos; Karapanagiotis, Stelios; Tsele, Nikoletta; Tsakoniti, Kalliopi; Gkagkavouzis, Konstantinos; Mylonas, Constantinos C; Kormas, Konstantinos Ar.; Mente, Eleni; Antonopoulou, Efthimia

Advances in understanding the mitogenic, metabolic, and cell death signaling in teleost development: the case of greater amberjack (Seriola dumerili, Risso 1810) Journal Article

Fish Physiology and Biochemistry, 48 (6), pp. 1665–1684, 2022, ISSN: 0920-1742, 1573-5168.

Links | BibTeX

Papadaki, Maria; Kaitetzidou, Elisavet; Papadakis, Ioannis E; Sfakianakis, Dimitris G; Papandroulakis, Nikos; Mylonas, Constantinos C; Sarropoulou, Elena

Temperature-Biased miRNA Expression Patterns during European Sea Bass (Dicentrarchus labrax) Development Journal Article

International Journal of Molecular Sciences, 23 (19), pp. 11164, 2022, ISSN: 1422-0067.

Abstract | Links | BibTeX

@article{papadaki_temperature-biased_2022,
title = {Temperature-Biased miRNA Expression Patterns during European Sea Bass (Dicentrarchus labrax) Development},
author = {Maria Papadaki and Elisavet Kaitetzidou and Ioannis E Papadakis and Dimitris G Sfakianakis and Nikos Papandroulakis and Constantinos C Mylonas and Elena Sarropoulou},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/09/2022-Papadaki-IJMS-65.pdf
https://www.mdpi.com/1422-0067/23/19/11164},
doi = {10.3390/ijms231911164},
issn = {1422-0067},
year = {2022},
date = {2022-01-01},
urldate = {2022-09-27},
journal = {International Journal of Molecular Sciences},
volume = {23},
number = {19},
pages = {11164},
abstract = {Environmental effects and, particularly, temperature changes have been demonstrated to influence the activity, function, and well-being of teleosts. Temperature may change seasonally in the wild, and in captivity under aquaculture operations. Moreover, climate change is expected to shift temperature profiles worldwide. MicroRNAs (miRNA) are important temperature-sensitive gene-expression regulators acting at the post-transcriptional level. They are known to be key regulators in development, reproduction, and immune responses. Therefore, early larval development of the European sea bass (Dicentrarchus labrax), one of the most extensively cultured species in Mediterranean aquaculture, was investigated at early rearing temperatures, i.e., 15, 17.5, and 20 °C, in regard to the impact of temperatures on miRNAs through sncRNA high-throughput sequencing but also at the phenotypic level in terms of growth, sex, vision, and skeletal deformities. Expression profiling revealed stage- and temperature-specific miRNA expression targeting genes with roles in reproduction and immune response mainly at the flexion and all-fins stages. Similar stage- and temperature-specific results were also observed concerning the number of rod cells and lower jaw elongation. The present work presents for the first time highly promising results on the influence of early rearing temperature at the post-transcriptional level during European sea bass development, with a putative impact on reproduction and immune response, as well as regarding teleost vision and larval development.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2021

Papadaki, Maria; Mandalakis, Manolis; Anastasiou, Thekla I; Pouli, Marina; Asderis, Michalis; Katharios, Pantelis; Papandroulakis, Nikos; Mylonas, Constantinos C

Histological evaluation of sex differentiation and early sex identification in hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages Journal Article

Fish Physiology and Biochemistry, 47 (6), pp. 1777–1792, 2021, ISSN: 1573-5168.

Abstract | Links | BibTeX

@article{papadaki_histological_2021b,
title = {Histological evaluation of sex differentiation and early sex identification in hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages},
author = {Maria Papadaki and Manolis Mandalakis and Thekla I Anastasiou and Marina Pouli and Michalis Asderis and Pantelis Katharios and Nikos Papandroulakis and Constantinos C Mylonas},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/01/2021-Papadaki-FFB-82-pre-print.pdf
https://doi.org/10.1007/s10695-021-01007-7},
doi = {10.1007/s10695-021-01007-7},
issn = {1573-5168},
year = {2021},
date = {2021-12-01},
urldate = {2021-12-04},
journal = {Fish Physiology and Biochemistry},
volume = {47},
number = {6},
pages = {1777--1792},
abstract = {The histological process of gonadal differentiation, together with the endocrine changes of sex steroid hormones and some of their precursors, was studied in hatchery-produced greater amberjack Seriola dumerili from 101 until 408 days post-hatching (dph), with samplings conducted every 50 days. Histological processing showed that sex differentiation began at 101 dph with the formation of the ovarian cavity in females, while the presumptive males did not yet contain any germ cells in their gonad. At 150 dph, we observed the first germ cells in the developing testes. Sex differentiation in almost all sampled individuals was complete at 408 dph. No size dimorphism was observed between the sexes, and the sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC–MS/MS) to examine their role in the sex differentiation process. From the seven hormones, the only one that exhibited differences between the sexes was 11-KT and the plasma 11-KT concentration was found to be a useful indication of greater amberjack sex. Variations were observed in the mean values of Ad, Δ4, 11-KT, T, P4 and 17,20βP over time in one or both sexes, indicating their involvement in the sex differentiation process.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Oikonomou, Stavroula; Tsakogiannis, Alexandros; Kriaridou, Christina; Danis, Theodoros; Manousaki, Tereza; Chatziplis, Dimitris; Papandroulakis, Nikos; Mylonas, Constantinos C; Triantafyllidis, Alexandros; Tsigenopoulos, Costas S

First linkage maps and a pilot QTL analysis for early growth performance in common dentex (Dentex dentex) and sharpsnout seabream (Diplodus puntazzo) Journal Article

21 , pp. 100855, 2021, ISSN: 23525134.

Links | BibTeX

Corriero, Aldo; Wylie, Matthew J; Nyuji, Mitsuo; Zupa, Rosa; Mylonas, Constantinos C

Reproduction of greater amberjack (Seriola dumerili) and other members of the family Carangidae Journal Article

Rev Aquacult, pp. raq.12544, 2021, ISSN: 1753-5123, 1753-5131.

Links | BibTeX

Fakriadis, Ioannis; Mylonas, Constantinos C

Sperm quality of greater amberjack Seriola dumerili throughout the reproductive season and in response to GnRHa treatment with controlled release implants Journal Article

Fish Physiology and Biochemistry, 47 (2), pp. 281–292, 2021, ISSN: 1573-5168.

Abstract | Links | BibTeX

@article{fakriadis_sperm_2021,
title = {Sperm quality of greater amberjack Seriola dumerili throughout the reproductive season and in response to GnRHa treatment with controlled release implants},
author = {Ioannis Fakriadis and Constantinos C Mylonas},
url = {https://doi.org/10.1007/s10695-020-00910-9},
doi = {10.1007/s10695-020-00910-9},
issn = {1573-5168},
year = {2021},
date = {2021-01-01},
urldate = {2021-04-27},
journal = {Fish Physiology and Biochemistry},
volume = {47},
number = {2},
pages = {281--292},
abstract = {A wild-caught stock of greater amberjack Seriola dumerili reared in sea cages in two commercial aquaculture facilities in Greece was administered gonadotropin-releasing hormone agonist (GnRHa), loaded in controlled release implants, and was used in spawning induction experiments throughout the reproductive season. Sperm quality was evaluated using computer-assisted sperm analysis (CASA) before and after GnRHa administration and the extent of the spermiation period was determined. Males were in spermiation throughout the monitoring period from May 30 until July 18, at temperatures between 19 and 24 °C. However, lower sperm motility duration, density, and survival under cold storage were observed from early July onwards. Sperm quality did not recover after the end of spawning induction experiments in tanks and the return of the fish for 14–28 days to the sea cage in mid-July, which could be related to the high temperatures of this period. An improvement trend was observed in the quality of the milt collected on day 7 after a single GnRHa administration, but a significant decrease was observed on day 21 in sperm density, survival under cold storage, and straight line velocity (VSL). On the contrary, a double GnRHa administration spaced 14 days apart maintained the same sperm quality for a longer period of 29 days. Further spermiation enhancement experiments should be conducted in the future to describe in more detail the kinetics of sperm production after GnRHa therapy and its effects on sperm quality.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Dzyuba, Viktoriya; Cosson, Jacky; Papadaki, Maria; Mylonas, Constantinos C; Steinbach, Christoph; Rodina, Marek; Tučkova, Vladimira; Linhart, Otomar; Shelton, William L; Gela, David; Boryshpolets, Sergii; Dzyuba, Borys

Influence of Environmental Temperature and Hormonal Stimulation on the In Vitro Sperm Maturation in Sterlet Acipenser ruthenus in Advance of the Spawning Season Journal Article

Animals, 11 (5), pp. 1417, 2021, ISSN: 2076-2615.

Abstract | Links | BibTeX

@article{dzyuba_influence_2021,
title = {Influence of Environmental Temperature and Hormonal Stimulation on the In Vitro Sperm Maturation in Sterlet Acipenser ruthenus in Advance of the Spawning Season},
author = {Viktoriya Dzyuba and Jacky Cosson and Maria Papadaki and Constantinos C Mylonas and Christoph Steinbach and Marek Rodina and Vladimira Tučkova and Otomar Linhart and William L Shelton and David Gela and Sergii Boryshpolets and Borys Dzyuba},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/06/2021-Dzyuba-Animals-45.pdf
https://www.mdpi.com/2076-2615/11/5/1417},
doi = {10.3390/ani11051417},
issn = {2076-2615},
year = {2021},
date = {2021-01-01},
urldate = {2021-06-24},
journal = {Animals},
volume = {11},
number = {5},
pages = {1417},
abstract = {Sturgeon sperm maturation occurs outside the testes during the transit of testicular spermatozoa (TS) through the kidneys and the Wolffian ducts. A method of in vitro TS maturation in sterlet Acipenser ruthenus was used to investigate the effects of temperature and hormonal stimulation of spermiation on the ability of TS to complete this process. Spermatozoa motility parameters after in vitro maturation of testicular sperm, concentrations of sex steroid hormones and testis morphology were studied in three groups of sterlet: (1) after overwintering in ponds (OW), (2) adapted to spawning temperature (ST), and (3) adapted to spawning temperature with hormonal induction of spermiation (ST-HI). Blood plasma concentrations of testosterone, 11-ketotestosterone and 17,20β-dihydroxy-pregnenolone increased significantly after hormonal induction of spermiation (group ST-HI). In all groups, TS were not motile. After in vitro sperm maturation, motility was up to 60% only in group ST-HI. The data suggest that the ability of TS to be matured in vitro was not related to the environmental temperature, while hormonal stimulation of spermiation during the spawning season was an absolute requirement for optimal in vitro maturation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Superio, Joshua; Fakriadis, Ioannis; Tsigenopoulos, Costas S; Lancerotto, Stefano Adam; Rodriguez, Andrea Villena; Vervelakis, Emanuele; Mylonas, Constantinos C

Spawning kinetics and parentage contribution of European sea bass (Dicentrarchus labrax) broodstocks, and influence of GnRHa-induced spawning Journal Article

Aquaculture Reports, 21 , pp. 100766, 2021, ISSN: 23525134.

Links | BibTeX

Chatzifotis, Stavros; Gutiérrez, Abraham Gómez; Papadaki, Maria; Caruso, Fabrizio; Sigelaki, Irini; Mylonas, Constantinos C

Lack of negative effects of fasting of gilthead seabream (Sparus aurata) breeders during the spawning period on maternal and egg nutrient composition, fertilization success, and early embryo/larval development Journal Article

Fish Physiology and Biochemistry, 47 (4), pp. 1257–1270, 2021, ISSN: 0920-1742, 1573-5168.

Links | BibTeX

Corriero, Aldo; Zupa, Rosa; Mylonas, Constantinos C; Passantino, Letizia

Atresia of ovarian follicles in fishes, and implications and uses in aquaculture and fisheries Journal Article

Journal of Fish Diseases, 44 (9), pp. 1271–1291, 2021, ISSN: 0140-7775, 1365-2761.

Links | BibTeX

Papadaki, Maria; Mandalakis, Manolis; Anastasiou, Thekla I; Pouli, Marina; Asderis, Michalis; Katharios, Pantelis; Papandroulakis, Nikos; Mylonas, Constantinos C

Histological evaluation of sex differentiation and early sex identification in hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages Journal Article

Fish Physiology and Biochemistry, 47 (6), pp. 1777–1792, 2021, ISSN: 1573-5168.

Abstract | Links | BibTeX

@article{papadaki_histological_2021,
title = {Histological evaluation of sex differentiation and early sex identification in hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages},
author = {Maria Papadaki and Manolis Mandalakis and Thekla I Anastasiou and Marina Pouli and Michalis Asderis and Pantelis Katharios and Nikos Papandroulakis and Constantinos C Mylonas},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/12/2021-Papadaki-FFB-69-pre-print-1.pdf
https://doi.org/10.1007/s10695-021-01007-7},
doi = {10.1007/s10695-021-01007-7},
issn = {1573-5168},
year = {2021},
date = {2021-01-01},
urldate = {2021-12-04},
journal = {Fish Physiology and Biochemistry},
volume = {47},
number = {6},
pages = {1777--1792},
abstract = {The histological process of gonadal differentiation, together with the endocrine changes of sex steroid hormones and some of their precursors, was studied in hatchery-produced greater amberjack Seriola dumerili from 101 until 408 days post-hatching (dph), with samplings conducted every 50 days. Histological processing showed that sex differentiation began at 101 dph with the formation of the ovarian cavity in females, while the presumptive males did not yet contain any germ cells in their gonad. At 150 dph, we observed the first germ cells in the developing testes. Sex differentiation in almost all sampled individuals was complete at 408 dph. No size dimorphism was observed between the sexes, and the sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC–MS/MS) to examine their role in the sex differentiation process. From the seven hormones, the only one that exhibited differences between the sexes was 11-KT and the plasma 11-KT concentration was found to be a useful indication of greater amberjack sex. Variations were observed in the mean values of Ad, Δ4, 11-KT, T, P4 and 17,20βP over time in one or both sexes, indicating their involvement in the sex differentiation process.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2020

Bolgan, Marta; Pereira, Beatriz P; Crucianelli, Aurora; Mylonas, Constantinos C; Pousão-Ferreira, Pedro; Parmentier, Eric; Fonseca, Paulo J; Amorim, Clara M P

Vocal repertoire and consistency of call features in the meagre Argyrosomous regius (Asso, 1801) Journal Article

PLOS ONE, 15 (11), pp. e0241792, 2020, ISSN: 1932-6203.

Abstract | Links | BibTeX

@article{bolgan_vocal_2020,
title = {Vocal repertoire and consistency of call features in the meagre Argyrosomous regius (Asso, 1801)},
author = {Marta Bolgan and Beatriz P Pereira and Aurora Crucianelli and Constantinos C Mylonas and Pedro Pousão-Ferreira and Eric Parmentier and Paulo J Fonseca and Clara M P Amorim},
editor = {Dennis M Higgs},
url = {https://dx.plos.org/10.1371/journal.pone.0241792},
doi = {10.1371/journal.pone.0241792},
issn = {1932-6203},
year = {2020},
date = {2020-11-01},
urldate = {2020-12-08},
journal = {PLOS ONE},
volume = {15},
number = {11},
pages = {e0241792},
abstract = {Passive Acoustic Monitoring (PAM) is a non-intrusive and cost-effective method capable of providing high-resolution, long-term information on the status and health of vocal populations and communities. To successfully monitor the same species over wide geographical and temporal scales, it is necessary to characterise the range of sound variability, as well as the consistency of sound features between populations. The meagre (
Argyrosomus regius
, Asso 1801) is an interesting case study because recent investigations suggest a wider vocal repertoire than previously described. In this study, meagre vocalizations were recorded and analysed from a variety of settings, ranging from rearing facilities to wild populations to provide a comprehensive characterisation of its vocal repertoire, while investigating the consistency of spawning sound features between populations. All sounds presented a similar acoustic structure in their basic unit (
i
.
e
. the pulse), while an important variability was found in the number of pulses; the meagre can emit sounds made of one single pulse or many pulses (up to more than 100). High level of overlap in the Principal Component Analysis made difficult to differentiate sound type clusters. Despite this, two sound types were identifiable: knocks (sounds from 1 to 3 pulses) and long grunts (sounds with more than 29 pulses). Discriminant Analysis carried out on PCA residuals showed that knock had the highest proportion of correct placement (92% of the observations correctly placed) followed by long grunts (80%). All other previously described sound types (intermediate grunt, short grunt and disturbance sounds) could not be separated and presented low levels of correct placement, suggesting that care should be taken when defining these as independent sound types. Finally, acoustic features consistency was found in meagre grunts emitted by different populations during spawning nights; statistical differences could be explained by recording settings and fish conditions. The results of this study provide important information for fostering PAM programs of wild meagre populations, while contributing to the discussion around the definition of fish sound types in vocal fish communities. Studies of this kind, which evaluate both variability and consistency of sound features, are of fundamental importance for maximising PAM efforts in the wild, at both the specific and the community level.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Passive Acoustic Monitoring (PAM) is a non-intrusive and cost-effective method capable of providing high-resolution, long-term information on the status and health of vocal populations and communities. To successfully monitor the same species over wide geographical and temporal scales, it is necessary to characterise the range of sound variability, as well as the consistency of sound features between populations. The meagre (
Argyrosomus regius
, Asso 1801) is an interesting case study because recent investigations suggest a wider vocal repertoire than previously described. In this study, meagre vocalizations were recorded and analysed from a variety of settings, ranging from rearing facilities to wild populations to provide a comprehensive characterisation of its vocal repertoire, while investigating the consistency of spawning sound features between populations. All sounds presented a similar acoustic structure in their basic unit (
i
.
e
. the pulse), while an important variability was found in the number of pulses; the meagre can emit sounds made of one single pulse or many pulses (up to more than 100). High level of overlap in the Principal Component Analysis made difficult to differentiate sound type clusters. Despite this, two sound types were identifiable: knocks (sounds from 1 to 3 pulses) and long grunts (sounds with more than 29 pulses). Discriminant Analysis carried out on PCA residuals showed that knock had the highest proportion of correct placement (92% of the observations correctly placed) followed by long grunts (80%). All other previously described sound types (intermediate grunt, short grunt and disturbance sounds) could not be separated and presented low levels of correct placement, suggesting that care should be taken when defining these as independent sound types. Finally, acoustic features consistency was found in meagre grunts emitted by different populations during spawning nights; statistical differences could be explained by recording settings and fish conditions. The results of this study provide important information for fostering PAM programs of wild meagre populations, while contributing to the discussion around the definition of fish sound types in vocal fish communities. Studies of this kind, which evaluate both variability and consistency of sound features, are of fundamental importance for maximising PAM efforts in the wild, at both the specific and the community level.

Fakriadis, Ioannis; Zanatta, Eugenio Maria; Fleck, Renata Pontes Dos Santos; Mateo, Daybet Lorena Sena; Papadaki, Maria; Mylonas, Constantinos C

Endocrine regulation of long-term enhancement of spermiation in meagre (Argyrosomus regius) with GnRHa controlled-delivery systems Journal Article

General and Comparative Endocrinology, 297 , pp. 113549, 2020, ISSN: 00166480.

Links | BibTeX

Papadaki, Maria; Kaitetzidou, Elisavet; Mylonas, Constantinos C; Sarropoulou, Elena

Non-coding RNA Expression Patterns of Two Different Teleost Gonad Maturation Stages Journal Article

Marine Biotechnology, 22 (5), pp. 683–695, 2020, ISSN: 1436-2228, 1436-2236.

Links | BibTeX

Pérez, José A; Papadakis, Ioannis E; Papandroulakis, Nikos; Cruces, Lorenzo; Cotou, Efthimia; Gisbert, Enric; Lorenzo, Antonio; Mylonas, Constantinos C; Rodríguez, Covadonga

The ontogeny of greater amberjack digestive and antioxidant defence systems under different rearing conditions: A histological and enzymatic approach Journal Article

Aquaculture Nutrition, pp. anu.13128, 2020, ISSN: 1353-5773, 1365-2095.

Links | BibTeX

Passantino, L; Zupa, R; Pousis, C; Mylonas, C C; Hala, E; Jirillo, E; Corriero, A

Increased melanomacrophage centres in the liver of reproductively dysfunctional female greater amberjack Seriola dumerili (Risso, 1810) Journal Article

Journal of Fish Diseases, 43 , pp. 503–514, 2020, ISSN: 1365-2761 (Electronic) 0140-7775 (Linking), (Type: Journal Article).

Links | BibTeX

Fakriadis, Ioannis; Miccoli, Andrea; Karapanagiotis, Stelios; Tsele, Nikoleta; Mylonas, Constantinos C

Optimization of a GnRHa treatment for spawning commercially reared greater amberjack Seriola dumerili: Dose response and extent of the reproductive season Journal Article

Aquaculture, 521 , 2020, ISSN: 00448486, (Type: Journal Article).

Links | BibTeX

Fakriadis, Ioannis; Sigelaki, Irini; Papadaki, Maria; Papandroulakis, Nikos; Raftopoulos, Anastasios; Tsakoniti, Kalliopi; Mylonas, Constantinos C

Control of reproduction of greater amberjack Seriola dumerili reared in aquaculture facilities Journal Article

Aquaculture, 519 , 2020, ISSN: 00448486, (Type: Journal Article).

Links | BibTeX

@article{fakriadis_control_2020,
title = {Control of reproduction of greater amberjack Seriola dumerili reared in aquaculture facilities},
author = {Ioannis Fakriadis and Irini Sigelaki and Maria Papadaki and Nikos Papandroulakis and Anastasios Raftopoulos and Kalliopi Tsakoniti and Constantinos C Mylonas},
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doi = {10.1016/j.aquaculture.2019.734880},
issn = {00448486},
year = {2020},
date = {2020-01-01},
journal = {Aquaculture},
volume = {519},
note = {Type: Journal Article},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Bolgan, M; Crucianelli, A; Mylonas, C C; Henry, S; Falguière, J C; Parmentier, E

Calling activity and calls' temporal features inform about fish reproductive condition and spawning in three cultured Sciaenidae species Journal Article

Aquaculture, 524 , 2020, ISSN: 00448486, (Type: Journal Article).

Links | BibTeX

2019

Ramos-Júdez, Sandra; González, Wendy; Dutto, Gilbert; Mylonas, Constantinos C; Fauvel, Christian; Duncan, Neil

Gamete quality and management for in vitro fertilisation in meagre (Argyrosomus regius) Journal Article

Aquaculture, 509 , pp. 227–235, 2019, ISSN: 00448486, (Type: Journal Article).

Links | BibTeX

Pousis, Chrysovalentinos; Rodríguez, Covadonga; Ruvo, Pasquale De; Virgilio, Caterina De; Pérez, José A; Mylonas, Constantinos C; Zupa, Rosa; Passantino, Letizia; Santamaria, Nicoletta; Valentini, Luisa; Corriero, Aldo

Vitellogenin receptor and fatty acid profiles of individual lipid classes of oocytes from wild and captive-reared greater amberjack (Seriola dumerili) during the reproductive cycle Journal Article

Theriogenology, 140 , pp. 73–83, 2019, ISSN: 0093-691X, (Type: Journal Article).

Links | BibTeX

Pérez, Evaristo; Linares, Fátima; Villanueva, José Luis Rodríguez; Vilar, Antonio; Mylonas, Constantinos C; Fakriadis, Ioannis; Papadaki, Maria; Papandroulakis, Nikos; Papadakis, Ioannis; Robles, Rocío; Fauvel, Christian; Roo, Javier; Peleteiro, José Benito; Lluch, Nuria; Pazos, Gema; Méndez, Belén; Sigelaki, Irini; Gómez, Castora; Pérez, Montse; Álvarez-Blázquez, Blanca

Wreckfish (Polyprion americanus). New Knowledge About Reproduction, Larval Husbandry, and Nutrition. Promise as a New Species for Aquaculture Journal Article

Fishes, 4 (1), pp. 14, 2019, (Type: Journal Article).

BibTeX

Forner-Piquer, Isabel; Fakriadis, Ioannis; Mylonas, Constantinos C; Piscitelli, Fabiana; Marzo, Vincenzo Di; Maradonna, Francesca; Calduch-Giner, Josep; Pérez-Sánchez, Jaume; Carnevali, Oliana

Effects of Dietary Bisphenol A on the Reproductive Function of Gilthead Sea Bream (Sparus aurata) Testes Journal Article

International Journal of Molecular Sciences, 20 (20), pp. 5003, 2019, (Type: Journal Article).

Links | BibTeX

Forner-Piquer, Isabel; Mylonas, Constantinos C; Fakriadis, Ioannis; Papadaki, Maria; Piscitelli, Fabiana; Marzo, Vincenzo Di; Calduch-Giner, Josep; Pérez-Sánchez, Jaume; Carnevali, Oliana

Effects of diisononyl phthalate (DiNP) on the endocannabinoid and reproductive systems of male gilthead sea bream (Sparus aurata) during the spawning season Journal Article

Archives of Toxicology, 2019, ISSN: 1432-0738, (Type: Journal Article).

Links | BibTeX

Fakriadis, I; Lisi, F; Sigelaki, I; Papadaki, M; Mylonas, C C

Spawning kinetics and egg/larval quality of greater amberjack (Seriola dumerili) in response to multiple GnRHa injections or implants Journal Article

General and Comparative Endocrinology, 279 , pp. 78–87, 2019, ISSN: 1095-6840 (Electronic) 0016-6480 (Linking), (Type: Journal Article).

Links | BibTeX

Carnevali, O; Santobuono, M; Forner-Piquer, I; Randazzo, B; Mylonas, C C; Ancillai, D; Giorgini, E; Maradonna, F

Dietary diisononylphthalate contamination induces hepatic stress: a multidisciplinary investigation in gilthead seabream (Sparus aurata) liver Journal Article

Archives of Toxicology, 93 (8), pp. 2361–2373, 2019, ISSN: 1432-0738 (Electronic) 0340-5761 (Linking), (Type: Journal Article).

Links | BibTeX

Carnevali, O; Giorgini, E; Canuti, D; Mylonas, C C; Forner-Piquer, I; Maradonna, F

Diets contaminated with Bisphenol A and Di-isononyl phtalate modify skeletal muscle composition: A new target for environmental pollutant action Journal Article

Science of the Total Environment, 658 , pp. 250–259, 2019, ISSN: 1879-1026 (Electronic) 0048-9697 (Linking), (Type: Journal Article).

Links | BibTeX

Brambila-Souza, G; Mylonas, C C; Mello, P H; Kuradomi, R Y; Batlouni, S R; Tolussi, C E; Moreira, R G

Thermal manipulation and GnRHa therapy applied to the reproduction of lambari-do-rabo-amarelo, Astyanax altiparanae females (Characiformes: Characidae) during the non-breeding season Journal Article

General and Comparative Endocrinology, 279 , pp. 120–128, 2019, ISSN: 0016-6480, (Type: Journal Article).

Links | BibTeX

2018

Pousis, C; Mylonas, C C; Virgilio, De C; Gadaleta, G; Santamaria, N; Passantino, L; Zupa, R; Papadaki, M; Fakriadis, I; Ferreri, R; Corriero, A

The observed oogenesis impairment in greater amberjack Seriola dumerili (Risso, 1810) reared in captivity is not related to an insufficient liver transcription or oocyte uptake of vitellogenin Journal Article

Aquaculture Research, 49 (1), pp. 243–252, 2018, ISSN: 1355557X, (Publisher: Blackwell Publishing Ltd).

Abstract | Links | BibTeX

@article{pousis_observed_2018,
title = {The observed oogenesis impairment in greater amberjack Seriola dumerili (Risso, 1810) reared in captivity is not related to an insufficient liver transcription or oocyte uptake of vitellogenin},
author = {C Pousis and C C Mylonas and C De Virgilio and G Gadaleta and N Santamaria and L Passantino and R Zupa and M Papadaki and I Fakriadis and R Ferreri and A Corriero},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026499054&doi=10.1111%2fare.13453&partnerID=40&md5=ecb8f6c6b9bbbf8b803322299447cfd4},
doi = {10.1111/are.13453},
issn = {1355557X},
year = {2018},
date = {2018-01-01},
journal = {Aquaculture Research},
volume = {49},
number = {1},
pages = {243--252},
abstract = {The greater amberjack Seriola dumerili is an excellent candidate for the Mediterranean aquaculture, due to its large body size and high growth rate, as well as its high flesh quality and commercial value worldwide. For its successful incorporation in the aquaculture industry, an in-depth understanding of the reproductive function of the species under rearing conditions is necessary, since completion of oogenesis in captivity is currently a bottleneck for the commercial production of the species. Liver and ovary samples from wild and captive-reared greater amberjack females were collected at three different phases of the reproductive cycle: early gametogenesis (EARLY, late April-early May), advanced gametogenesis (ADVANCED, late May-early June) and spawning (SPAWNING, late June-July). The cDNAs of three vitellogenins (VtgA, VtgB and VtgC) were partially sequenced and a qRT-PCR for their expression was used to compare ovarian maturity stage and liver vitellogenin transcript levels between wild and captive-reared individuals. An extensive atresia of late vitellogenic follicles, which prevented any further oocyte development and spawning was observed in captive-reared individuals during the ADVANCED phase. The expression levels of the three vitellogenins, as well as the amount of yolk globules in vitellogenic oocytes, did not differ significantly between captive-reared and wild females, indicating that the observed oogenesis impairment in greater amberjack reared in captivity was not related to an insufficient liver synthesis or a reduced oocyte uptake of vitellogenin. © 2017 John Wiley & Sons Ltd},
note = {Publisher: Blackwell Publishing Ltd},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Papadaki, M; Mazzella, D; Santinelli, V; Fakriadis, I; Sigelaki, I; Mylonas, C C

Hermaphroditism and reproductive function of hatchery-produced sharpsnout seabream (Diplodus puntazzo) under attenuated annual thermal cycles Journal Article

Aquaculture, 482 , pp. 231–240, 2018, ISSN: 00448486, (Publisher: Elsevier B.V.).

Abstract | Links | BibTeX

@article{papadaki_hermaphroditism_2018,
title = {Hermaphroditism and reproductive function of hatchery-produced sharpsnout seabream (Diplodus puntazzo) under attenuated annual thermal cycles},
author = {M Papadaki and D Mazzella and V Santinelli and I Fakriadis and I Sigelaki and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030865182&doi=10.1016%2fj.aquaculture.2017.09.028&partnerID=40&md5=61ad82357d509cb8f19491299ca570e0},
doi = {10.1016/j.aquaculture.2017.09.028},
issn = {00448486},
year = {2018},
date = {2018-01-01},
journal = {Aquaculture},
volume = {482},
pages = {231--240},
abstract = {Acquiring more knowledge on the reproductive biology of the sharpsnout seabream (Diplodus puntazzo) can improve our ability to control its reproduction and enable hatcheries to reconsider this fish as a potential species for the Mediterranean aquaculture production. We investigated hermaphroditism and reproductive function in a hatchery-produced broodstock over a long period of 6 years, which includes sex differentiation, puberty and four consecutive annual reproductive seasons, at relatively constant water temperatures of 18–20 °C, which are typical of borehole seawater supplies used frequently in marine hatcheries for biosecurity reasons. At the end of the first year of life, the gonads were bisexual and were classified into three different categories: mainly testicular tissue with rudimentary ovarian tissue (Mf), substantial amounts of both tissues (MF) and mainly ovarian tissue with rudimentary testicular tissue (mF). Fully female (F) gonads appeared already in 1 + years old fish, whereas fully male (M) gonads appeared for the first time in 2 + years old fish. The sex ratio (F:M) of the studied populations during the first 6 years of life in all age classes was not different from 1:1. Therefore, no annual restructuring of the broodstock is necessary in order to avoid the development of skewed sex ratios, since once functional sex is established it does not seem to change in the following years. Furthermore, the use of attenuated annual thermal cycling regimes did not seem to affect the annual gametogenic cycle and full maturation of this species, though spontaneous spawning was still missing and the fish exhibited the typical problems reported for this species in captivity. © 2017 Elsevier B.V.},
note = {Publisher: Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Tsakogiannis, Alexandros; Manousaki, Tereza; Lagnel, Jacques; Papanikolaou, Nikolaos; Papandroulakis, Nikos; Mylonas, Constantinos C; Tsigenopoulos, Costas S

The gene toolkit implicated in functional sex in Sparidae hermaphrodites: inferences from comparative transcriptomics Journal Article

Frontiers in Genetics, 9 , pp. 749, 2018, (Publisher: Frontiers).

BibTeX

Tsakogiannis, A; Manousaki, T; Lagnel, J; Sterioti, A; Pavlidis, M; Papandroulakis, N; Mylonas, CC; Tsigenopoulos, CS

The transcriptomic signature of different sexes in two protogynous hermaphrodites: Insights into the molecular network underlying sex phenotype in fish Journal Article

Scientific reports, 8 (1), pp. 3564, 2018, (Publisher: Nature Publishing Group).

BibTeX

Papadakis, I E; Kentouri, M; Divanach, P; Mylonas, C C

Ontogeny of the eye of meagre (Argyrosomus regius) from hatching to juvenile and implications to commercial larval rearing Journal Article

Aquaculture, 484 , pp. 32–43, 2018, ISSN: 00448486, (Publisher: Elsevier B.V.).

Abstract | Links | BibTeX

@article{papadakis_ontogeny_2018,
title = {Ontogeny of the eye of meagre (Argyrosomus regius) from hatching to juvenile and implications to commercial larval rearing},
author = {I E Papadakis and M Kentouri and P Divanach and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032915502&doi=10.1016%2fj.aquaculture.2017.10.038&partnerID=40&md5=6d5582db60caf9774e0ef281ba47a57f},
doi = {10.1016/j.aquaculture.2017.10.038},
issn = {00448486},
year = {2018},
date = {2018-01-01},
journal = {Aquaculture},
volume = {484},
pages = {32--43},
abstract = {The histological development of the visual system of meagre (Argyrosomus regius) was studied from hatching to juvenile stage (44 days post hatching, dph), under aquaculture rearing conditions. The cones, horizontal, bipolar, amacrine and ganglia cells appeared already at 3 dph at a total body length (TL) of 3.11 ± 0.21 mm, at the stage of mouth opening. Rods appeared at 6 dph (TL 4.16 ± 0.73 mm) and increased their density continually during the monitoring period. On the contrary at the same period, the evolution of the number of cones, horizontal, bipolar, amacrine and ganglia cells in the retina were reduced. While photopic sensitivity increased over time, meagre may be considered as a species with well-developed scotopic sensitivity as well, already by 17 dph (TL 8.14 ± 1.64 mm). This observation suggests that instead of the commonly used 24-h continuous high light intensities used in larval rearing protocols of meagre, lower light intensities should be employed, especially during the night hours. Histological visual acuity increased with larval development and appeared to stabilize by the early juvenile stage. Based on the estimated histological visual acuity and the theoretical distance at which rotifers and Artemia may be identified by meagre larvae, minimum prey densities should be 0.5 rotifers and 0.009 Artemia ml− 1 during their first use as feed items. The study demonstrated that the majority of ontogenetic events that are related with retinal differentiation and the function of the eye occurred very early during larval development in meagre. The results provide important information for the biology of the species, as well as for the optimization of larval rearing conditions regarding light management and prey item density under aquaculture conditions. © 2017 Elsevier B.V.},
note = {Publisher: Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Jerez, Salvador; Fakriadis, Ioannis; Papadaki, Maria; Martín, M; Cejas, Juana; Mylonas, Constantinos C

Spawning induction of first-generation (F1) greater amberjack Seriola dumerili in the Canary Islands, Spain using GnRHa delivery systems Journal Article

Fishes, 3 (3), pp. 1–22, 2018, ISSN: 2410-3888, (Type: Journal Article).

Links | BibTeX

Papadaki, Maria; Peleteiro, José Benito; Alvarez-Blázquez, Blanca; Villanueva, José Luis Rodríguez; Linares, Fatima; Vilar, Antonio; Rial, Evaristo Pérez; Lluch, Nuria; Fakriadis, Ioannis; Sigelaki, Irini; Mylonas, Constantinos C

Description of the Annual Reproductive Cycle of Wreckfish Polyprion americanus in Captivity Journal Article

Fishes, 3 (4), pp. 1–20, 2018, ISSN: 2410-3888, (Type: Journal Article).

Links | BibTeX

Forner-Piquer, Isabel; Mylonas, Constantinos C; Calduch-Giner, Josep; Maradonna, Francesca; Gioacchini, Giorgia; Allarà, Marco; Piscitelli, Fabiana; Marzo, Vincenzo Di; Pérez-Sánchez, Jaume; Carnevali, Oliana

Endocrine disruptors in the diet of male Sparus aurata: Modulation of the endocannabinoid system at the hepatic and central level by Di-isononyl phthalate and Bisphenol A Journal Article

Environment International, 119 , pp. 54–65, 2018, ISSN: 0160-4120, (Type: Journal Article).

Links | BibTeX

Duncan, Neil J; Mylonas, Constantinos C; Sullon, Edwards Milton; Karamanlidis, Dimitris; Nogueira, Maria Claudia França; Ibarra-Zatarain, Zohar; Chiumento, Marco; Carrillo, Ricardo Olinser Aviles

Paired spawning with male rotation of meagre Argyrosomus regius using GnRHa injections, as a method for producing multiple families for breeding selection programs Journal Article

Aquaculture, 495 , pp. 506–512, 2018, ISSN: 00448486, (Type: Journal Article).

Links | BibTeX

2017

Antoniou, A; Kasapidis, P; Kotoulas, G; Mylonas, C C; Magoulas, A

Genetic diversity of Atlantic Bluefin tuna in the Mediterranean Sea: Insights from genome-wide SNPs and microsatellites Journal Article

Journal of Biological Research-Thessaloniki, 24 (1), pp. 3, 2017.

Abstract | Links | BibTeX

@article{antoniou_genetic_2017,
title = {Genetic diversity of Atlantic Bluefin tuna in the Mediterranean Sea: Insights from genome-wide SNPs and microsatellites},
author = {A Antoniou and P Kasapidis and G Kotoulas and C C Mylonas and A Magoulas},
doi = {10.1186/s40709-017-0062-2},
year = {2017},
date = {2017-01-01},
journal = {Journal of Biological Research-Thessaloniki},
volume = {24},
number = {1},
pages = {3},
abstract = {© The Author(s) 2017. Background: Elucidating the patterns of the Atlantic Bluefin tuna [ABFT, Thunnus thynnus (Linnaeus, 1758)] population structure constitutes a challenging task of great importance. Most of the unique challenges stem from its biology, as well as the attributes of the marine realm in which it disperses. Accurate information is urgently needed for stock assessment, and the identification of critical features to the persistence and adaptation of populations in order to formulate and adopt effective strategies for ABFT conservation and management. Conclusions of a great number of ABFT genetic studies on the Mediterranean Sea stock structure are rather controversial and not yet conclusive. In this study, ABFT genomic diversity was investigated in the Mediterranean Sea, which is the most important area for the species' reproduction. Results: Analyzing genome-wide SNPs and microsatellites from ABFT samples collected throughout the Mediterranean Sea did not provide strong evidence of genetic structure, pointing towards the existence of a single panmictic unit. An alternative view would recognize a failure to reject the null hypothesis of a panmictic unit as an effect of the study's sampling design, the type of markers used, and the effectiveness/suitability of analysis methods in respect to the species biological characteristics or any combination of the above. Conclusions: Unravelling the drivers of ABFT population diversity would require the consideration of important aspects of the species spawning behavior for the determination of the appropriate sampling design. Novel approaches and methods of analysis that will bring together experts in genetics/-omics, ecology and oceanography are deemed necessary. Analyzing ABFT genetic data under the discipline of seascape genetics could provide the analysis framework under which major abiotic and biotic forces controlling ABFT recruitment could be identified, elucidating the complicated population dynamics of the species, while multiple and continuous fisheries monitoring should in all cases be considered as a prerequisite in order to achieve efficient and long-term ABFT conservation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

© The Author(s) 2017. Background: Elucidating the patterns of the Atlantic Bluefin tuna [ABFT, Thunnus thynnus (Linnaeus, 1758)] population structure constitutes a challenging task of great importance. Most of the unique challenges stem from its biology, as well as the attributes of the marine realm in which it disperses. Accurate information is urgently needed for stock assessment, and the identification of critical features to the persistence and adaptation of populations in order to formulate and adopt effective strategies for ABFT conservation and management. Conclusions of a great number of ABFT genetic studies on the Mediterranean Sea stock structure are rather controversial and not yet conclusive. In this study, ABFT genomic diversity was investigated in the Mediterranean Sea, which is the most important area for the species' reproduction. Results: Analyzing genome-wide SNPs and microsatellites from ABFT samples collected throughout the Mediterranean Sea did not provide strong evidence of genetic structure, pointing towards the existence of a single panmictic unit. An alternative view would recognize a failure to reject the null hypothesis of a panmictic unit as an effect of the study's sampling design, the type of markers used, and the effectiveness/suitability of analysis methods in respect to the species biological characteristics or any combination of the above. Conclusions: Unravelling the drivers of ABFT population diversity would require the consideration of important aspects of the species spawning behavior for the determination of the appropriate sampling design. Novel approaches and methods of analysis that will bring together experts in genetics/-omics, ecology and oceanography are deemed necessary. Analyzing ABFT genetic data under the discipline of seascape genetics could provide the analysis framework under which major abiotic and biotic forces controlling ABFT recruitment could be identified, elucidating the complicated population dynamics of the species, while multiple and continuous fisheries monitoring should in all cases be considered as a prerequisite in order to achieve efficient and long-term ABFT conservation.

Zupa, R; Rodrõâguez, C; Mylonas, C C; Rosenfeld, H; Fakriadis, I; Papadaki, M; Peârez, J A; Pousis, C; Basilone, G; Corriero, A

Comparative study of reproductive development in wild and captive-reared greater amberjack seriola dumerili (Risso, 1810) Journal Article

PLoS ONE, 12 (1), 2017, ISSN: 19326203, (Publisher: Public Library of Science).

Abstract | Links | BibTeX

@article{zupa_comparative_2017,
title = {Comparative study of reproductive development in wild and captive-reared greater amberjack seriola dumerili (Risso, 1810)},
author = {R Zupa and C Rodrõâguez and C C Mylonas and H Rosenfeld and I Fakriadis and M Papadaki and J A Peârez and C Pousis and G Basilone and A Corriero},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85008686824&doi=10.1371%2fjournal.pone.0169645&partnerID=40&md5=09301e14b368a835887bf0e7176db149},
doi = {10.1371/journal.pone.0169645},
issn = {19326203},
year = {2017},
date = {2017-01-01},
journal = {PLoS ONE},
volume = {12},
number = {1},
abstract = {The greater amberjack Seriola dumerili is a large teleost fish with rapid growth and excellent flesh quality, whose domestication represents an ambitious challenge for aquaculture. The occurrence of reproductive dysfunctions in greater amberjack reared in captivity was investigated by comparing reproductive development of wild and captive-reared individuals. Wild and captive-reared breeders were sampled in the Mediterranean Sea during three different phases of the reproductive cycle: Early gametogenesis (EARLY, late April-early May), advanced gametogenesis (ADVANCED, late May-early June) and spawning (SPAWNING, late June-July). Fish reproductive state was evaluated using the gonado-somatic index (GSI), histological analysis of the gonads and determination of sex steroid levels in the plasma, and correlated with leptin expression in the liver and gonad biochemical composition. The GSI and sex steroid levels were lower in captive-reared than in wild fish. During the ADVANCED period, when the wild greater amberjack breeders were already in spawning condition, ovaries of captive-reared breeders showed extensive atresia of late vitellogenic oocytes and spermatogenic activity ceased in the testes of half of the examined males. During the SPAWNING period, all captive-reared fish had regressed gonads, while wild breeders still displayed reproductive activity. Liver leptin expression and gonad proximate composition of wild and captive greater amberjack were similar. However, the gonads of captive-reared fish showed different total polar lipid contents, as well as specific lipid classes and fatty acid profiles with respect to wild individuals. This study underlines the need for an improvement in rearing technology for this species, which should include minimum handling during the reproductive season and the formulation of a specific diet to overcome the observed gonadal decrements of phospholipids, DHA (22:6n-3) and ARA (20:4n-6), compared to wild breeders. © 2017 Zupa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.},
note = {Publisher: Public Library of Science},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The greater amberjack Seriola dumerili is a large teleost fish with rapid growth and excellent flesh quality, whose domestication represents an ambitious challenge for aquaculture. The occurrence of reproductive dysfunctions in greater amberjack reared in captivity was investigated by comparing reproductive development of wild and captive-reared individuals. Wild and captive-reared breeders were sampled in the Mediterranean Sea during three different phases of the reproductive cycle: Early gametogenesis (EARLY, late April-early May), advanced gametogenesis (ADVANCED, late May-early June) and spawning (SPAWNING, late June-July). Fish reproductive state was evaluated using the gonado-somatic index (GSI), histological analysis of the gonads and determination of sex steroid levels in the plasma, and correlated with leptin expression in the liver and gonad biochemical composition. The GSI and sex steroid levels were lower in captive-reared than in wild fish. During the ADVANCED period, when the wild greater amberjack breeders were already in spawning condition, ovaries of captive-reared breeders showed extensive atresia of late vitellogenic oocytes and spermatogenic activity ceased in the testes of half of the examined males. During the SPAWNING period, all captive-reared fish had regressed gonads, while wild breeders still displayed reproductive activity. Liver leptin expression and gonad proximate composition of wild and captive greater amberjack were similar. However, the gonads of captive-reared fish showed different total polar lipid contents, as well as specific lipid classes and fatty acid profiles with respect to wild individuals. This study underlines the need for an improvement in rearing technology for this species, which should include minimum handling during the reproductive season and the formulation of a specific diet to overcome the observed gonadal decrements of phospholipids, DHA (22:6n-3) and ARA (20:4n-6), compared to wild breeders. © 2017 Zupa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Zupa, R; Fauvel, C; Mylonas, C C; Pousis, C; Santamaria, N; Papadaki, Μ; Fakriadis, I; Cicirelli, V; Mangano, S; Passantino, L; Lacalandra, G M; Corriero, A

Rearing in captivity affects spermatogenesis and sperm quality in greater amberjack, Seriola dumerili (Risso, 1810) Journal Article

Journal of Animal Science, 95 (9), pp. 4085–4100, 2017, ISSN: 00218812, (Publisher: American Society of Animal Science).

Abstract | Links | BibTeX

@article{zupa_rearing_2017,
title = {Rearing in captivity affects spermatogenesis and sperm quality in greater amberjack, Seriola dumerili (Risso, 1810)},
author = {R Zupa and C Fauvel and C C Mylonas and C Pousis and N Santamaria and Μ Papadaki and I Fakriadis and V Cicirelli and S Mangano and L Passantino and G M Lacalandra and A Corriero},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029717001&doi=10.2527%2fjas.2017.1708&partnerID=40&md5=93369a73080df336a351b6a9a006cab1},
doi = {10.2527/jas.2017.1708},
issn = {00218812},
year = {2017},
date = {2017-01-01},
journal = {Journal of Animal Science},
volume = {95},
number = {9},
pages = {4085--4100},
abstract = {The greater amberjack, Seriola dumerili (Risso, 1810), is a promising candidate for the diversification of European aquaculture production, but inconsistent reproduction in captivity prevents commercial production. Recent studies showed that greater amberjack confined in sea cages exhibited scarce gonad development and early interruption of gametogenic activity during the reproductive season. The aim of the present study was to improve our understanding of the observed impairment of spermatogenesis. Adult wild and captive-reared males were sampled during 3 different phases of the reproductive cycle: early gametogenesis (EARLY; late April to early May), advanced gametogenesis (ADVANCED; late May to early June), and spawning (SPAWNING; late June to July). Spermatogonial stem cells and proliferating germ cells were identified through the immunohistochemical localization of Pou5f1 and proliferating cell nuclear antigen, respectively. Apoptotic germ cells were identified throughout the terminal deoxynucleotidyl transferase-mediated 2’-deoxyuridine 5’-triphosphate nick end labeling method. Sperm quality of captive-reared fish was evaluated using computer-assisted sperm analysis. Captive-reared males exhibited seminiferous lobules of a smaller diameter, a precocious and progressive decrease of spermatogonial mitosis, and a high level of apoptosis at the beginning of the reproductive season, concomitant with a many-fold higher 17β-estradiol plasma concentration. The motile spermatozoa percentage of captive greater amberjack was lower than in other teleosts, and a drastic decrease of spermatozoa motility duration, velocity, and ATP content occurred along the reproductive season. An abnormal increase of sperm concentration as well as an increase of dead spermatozoa occurred during the SPAWNING phase, probably because of lack of sperm hydration and ejaculation and consequent sperm ageing. The present study demonstrates the extreme susceptibility of greater amberjack to rearing stress and underscores the need for improvement of the rearing and handling procedures to ameliorate gametogenesis dysfunctions in commercial aquaculture production. © 2017 American Society of Animal Science. All rights reserved.},
note = {Publisher: American Society of Animal Science},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The greater amberjack, Seriola dumerili (Risso, 1810), is a promising candidate for the diversification of European aquaculture production, but inconsistent reproduction in captivity prevents commercial production. Recent studies showed that greater amberjack confined in sea cages exhibited scarce gonad development and early interruption of gametogenic activity during the reproductive season. The aim of the present study was to improve our understanding of the observed impairment of spermatogenesis. Adult wild and captive-reared males were sampled during 3 different phases of the reproductive cycle: early gametogenesis (EARLY; late April to early May), advanced gametogenesis (ADVANCED; late May to early June), and spawning (SPAWNING; late June to July). Spermatogonial stem cells and proliferating germ cells were identified through the immunohistochemical localization of Pou5f1 and proliferating cell nuclear antigen, respectively. Apoptotic germ cells were identified throughout the terminal deoxynucleotidyl transferase-mediated 2’-deoxyuridine 5’-triphosphate nick end labeling method. Sperm quality of captive-reared fish was evaluated using computer-assisted sperm analysis. Captive-reared males exhibited seminiferous lobules of a smaller diameter, a precocious and progressive decrease of spermatogonial mitosis, and a high level of apoptosis at the beginning of the reproductive season, concomitant with a many-fold higher 17β-estradiol plasma concentration. The motile spermatozoa percentage of captive greater amberjack was lower than in other teleosts, and a drastic decrease of spermatozoa motility duration, velocity, and ATP content occurred along the reproductive season. An abnormal increase of sperm concentration as well as an increase of dead spermatozoa occurred during the SPAWNING phase, probably because of lack of sperm hydration and ejaculation and consequent sperm ageing. The present study demonstrates the extreme susceptibility of greater amberjack to rearing stress and underscores the need for improvement of the rearing and handling procedures to ameliorate gametogenesis dysfunctions in commercial aquaculture production. © 2017 American Society of Animal Science. All rights reserved.

Mylonas, C C; Duncan, N J; Asturiano, J F

Hormonal manipulations for the enhancement of sperm production in cultured fish and evaluation of sperm quality Journal Article

Aquaculture, 472 , pp. 21–44, 2017, ISSN: 00448486, (Publisher: Elsevier B.V.).

Abstract | Links | BibTeX

@article{mylonas_hormonal_2017,
title = {Hormonal manipulations for the enhancement of sperm production in cultured fish and evaluation of sperm quality},
author = {C C Mylonas and N J Duncan and J F Asturiano},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84964969855&doi=10.1016%2fj.aquaculture.2016.04.021&partnerID=40&md5=68c3de70b18d9ecee6769363d5b45a86},
doi = {10.1016/j.aquaculture.2016.04.021},
issn = {00448486},
year = {2017},
date = {2017-01-01},
journal = {Aquaculture},
volume = {472},
pages = {21--44},
abstract = {This article reviews the use of hormonal treatments to enhance sperm production in aquaculture fish and the methods available for evaluating sperm quality. The different types of testis development are examined and a brief review is presented of the endocrine regulation of spermatogenesis in fishes, including the increasing evidence of the existence of spermatozoa subpopulations. Hormonal manipulations are employed to induce spermatogenesis in species such as the freshwater eels, to synchronize maximal sperm volume to ovulation for in vitro fertilization and to enhance sperm production in species with poor spermiation. The hormones that are employed include gonadotropins (GtHs) of piscine or mammalian origin, and gonadotropin-releasing hormone agonists (GnRHa) administered by injections or controlled-release delivery systems, with or without dopaminergic inhibitors. Pheromones in the culture water and hormones added to the sperm in vitro have also been employed to enhance spermiation and sperm quality, respectively, in some fishes. Hormonal therapies usually do not affect sperm quality parameters, except in cases where fish fail to spermiate naturally or produce very small volumes of high-density sperm. Different parameters have been used to evaluate fish sperm quality, including sperm volume and density, spermatozoa motility and morphometry, and seminal plasma composition. The development of Computer-Assisted Sperm Analysis (CASA) systems made possible the estimation of a higher number of sperm motion parameters using an objective, sensitive and accurate technique. The development of Assisted Sperm Morphology Analysis (ASMA) software has introduced a new approach for sperm evaluation studies, demonstrating changes in the spermatozoa related to reproductive season, hormonal treatments or the cryopreservation processes, and how these may be related to changes in sperm motility and fertilization capacity. The article concludes with a few practical protocols for the enhancement of sperm production in aquaculture species. © 2016 Elsevier B.V.},
note = {Publisher: Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

This article reviews the use of hormonal treatments to enhance sperm production in aquaculture fish and the methods available for evaluating sperm quality. The different types of testis development are examined and a brief review is presented of the endocrine regulation of spermatogenesis in fishes, including the increasing evidence of the existence of spermatozoa subpopulations. Hormonal manipulations are employed to induce spermatogenesis in species such as the freshwater eels, to synchronize maximal sperm volume to ovulation for in vitro fertilization and to enhance sperm production in species with poor spermiation. The hormones that are employed include gonadotropins (GtHs) of piscine or mammalian origin, and gonadotropin-releasing hormone agonists (GnRHa) administered by injections or controlled-release delivery systems, with or without dopaminergic inhibitors. Pheromones in the culture water and hormones added to the sperm in vitro have also been employed to enhance spermiation and sperm quality, respectively, in some fishes. Hormonal therapies usually do not affect sperm quality parameters, except in cases where fish fail to spermiate naturally or produce very small volumes of high-density sperm. Different parameters have been used to evaluate fish sperm quality, including sperm volume and density, spermatozoa motility and morphometry, and seminal plasma composition. The development of Computer-Assisted Sperm Analysis (CASA) systems made possible the estimation of a higher number of sperm motion parameters using an objective, sensitive and accurate technique. The development of Assisted Sperm Morphology Analysis (ASMA) software has introduced a new approach for sperm evaluation studies, demonstrating changes in the spermatozoa related to reproductive season, hormonal treatments or the cryopreservation processes, and how these may be related to changes in sperm motility and fertilization capacity. The article concludes with a few practical protocols for the enhancement of sperm production in aquaculture species. © 2016 Elsevier B.V.

Neofytou, M; Sfakianakis, D G; Koumoundouros, G; Mylonas, C C; Kentouri, M

Skeletal ontogeny of the vertebral column and of the fins in shi drum Umbrina cirrosa (Teleostei: Perciformes: Sciaenidae), a new candidate species for aquaculture Journal Article

Journal of Fish Biology, 91 (3), pp. 764–788, 2017, ISSN: 00221112, (Publisher: Blackwell Publishing Ltd).

Abstract | Links | BibTeX

@article{neofytou_skeletal_2017,
title = {Skeletal ontogeny of the vertebral column and of the fins in shi drum Umbrina cirrosa (Teleostei: Perciformes: Sciaenidae), a new candidate species for aquaculture},
author = {M Neofytou and D G Sfakianakis and G Koumoundouros and C C Mylonas and M Kentouri},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026745417&doi=10.1111%2fjfb.13372&partnerID=40&md5=5a9624844d48cf931afbe372680fcd8a},
doi = {10.1111/jfb.13372},
issn = {00221112},
year = {2017},
date = {2017-01-01},
journal = {Journal of Fish Biology},
volume = {91},
number = {3},
pages = {764--788},
abstract = {The osteological development of the vertebral column and fins in shi drum Umbrina cirrosa was studied in order to improve knowledge for its introduction in Mediterranean aquaculture. The osteological development was studied in 171 individuals, of total length (LT) from 2·7 to 30·2 mm that were reared under the mesocosm technique. Vertebral ontogeny starts at 3·4 and 4·0 mm LT, with the formation of the first cartilaginous neural and haemal arches, and spines, respectively, and is completed with the full attainment of epicentrals (12·5 mm LT). The formation of vertebral centra occurs between 4·1 and 7·4 mm LT. Pectoral supports are the first fin elements to develop (3·0 mm LT), followed by those of the caudal fin (3·8 mm LT), pelvic fin (3·9 mm LT) and finally by those of the dorsal and anal fins (4·5 mm LT). The caudal fin is the first to develop fin rays and attain the full count of principal fin rays (4·5–6·8 mm LT), but the last to be fully completed with the formation of procurrent fin rays (6·9–17·5 mm LT). The next fins starting to present rays are the dorsal (5·3 mm LT) and the pectoral fins (5·6 mm LT), while the anal and pelvic fins are the last (5·7 mm LT). Following the caudal principal fin rays (6·8 mm LT), the dorsal, anal (6·9 mm LT), pelvic (7·4 mm LT) and pectoral fins (9·8 mm LT) are the next with fully completed ray counts. Aggregation of qualitative changes, such as the appearance of cartilages, the beginning and the complement of the ossification process and the full complement of elements in U. cirrosa were measured as cumulative frequency counts. These measurements reveal three ontogenetic intervals: one very developmentally active period during early life stages (from 3 to 5·9 mm LT), a second slower developmental period (from 6·0 to 8·9 mm LT) and finally a period of ontogeny more focused on structure refinement up to metamorphosis and settlement (>9·0 mm LT). © 2017 The Fisheries Society of the British Isles},
note = {Publisher: Blackwell Publishing Ltd},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The osteological development of the vertebral column and fins in shi drum Umbrina cirrosa was studied in order to improve knowledge for its introduction in Mediterranean aquaculture. The osteological development was studied in 171 individuals, of total length (LT) from 2·7 to 30·2 mm that were reared under the mesocosm technique. Vertebral ontogeny starts at 3·4 and 4·0 mm LT, with the formation of the first cartilaginous neural and haemal arches, and spines, respectively, and is completed with the full attainment of epicentrals (12·5 mm LT). The formation of vertebral centra occurs between 4·1 and 7·4 mm LT. Pectoral supports are the first fin elements to develop (3·0 mm LT), followed by those of the caudal fin (3·8 mm LT), pelvic fin (3·9 mm LT) and finally by those of the dorsal and anal fins (4·5 mm LT). The caudal fin is the first to develop fin rays and attain the full count of principal fin rays (4·5–6·8 mm LT), but the last to be fully completed with the formation of procurrent fin rays (6·9–17·5 mm LT). The next fins starting to present rays are the dorsal (5·3 mm LT) and the pectoral fins (5·6 mm LT), while the anal and pelvic fins are the last (5·7 mm LT). Following the caudal principal fin rays (6·8 mm LT), the dorsal, anal (6·9 mm LT), pelvic (7·4 mm LT) and pectoral fins (9·8 mm LT) are the next with fully completed ray counts. Aggregation of qualitative changes, such as the appearance of cartilages, the beginning and the complement of the ossification process and the full complement of elements in U. cirrosa were measured as cumulative frequency counts. These measurements reveal three ontogenetic intervals: one very developmentally active period during early life stages (from 3 to 5·9 mm LT), a second slower developmental period (from 6·0 to 8·9 mm LT) and finally a period of ontogeny more focused on structure refinement up to metamorphosis and settlement (>9·0 mm LT). © 2017 The Fisheries Society of the British Isles

Sarropoulou, E; Sundaram, A Y M; Kaitetzidou, E; Kotoulas, G; Gilfillan, G D; Papandroulakis, N; Mylonas, C C; Magoulas, A

Full genome survey and dynamics of gene expression in the greater amberjack Seriola dumerili Journal Article

GigaScience, 6 (12), pp. 1–13, 2017, ISSN: 2047217X, (Publisher: Oxford University Press).

Abstract | Links | BibTeX

@article{sarropoulou_full_2017,
title = {Full genome survey and dynamics of gene expression in the greater amberjack Seriola dumerili},
author = {E Sarropoulou and A Y M Sundaram and E Kaitetzidou and G Kotoulas and G D Gilfillan and N Papandroulakis and C C Mylonas and A Magoulas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042364258&doi=10.1093%2fgigascience%2fgix108&partnerID=40&md5=fa6e269b1e6ff57a26c0c9c6efe45226},
doi = {10.1093/gigascience/gix108},
issn = {2047217X},
year = {2017},
date = {2017-01-01},
journal = {GigaScience},
volume = {6},
number = {12},
pages = {1--13},
abstract = {Background: Teleosts of the genus Seriola, commonly known as amberjacks, are of high commercial value in international markets due to their flesh quality and worldwide distribution. The Seriola species of interest to Mediterranean aquaculture is the greater amberjack (Seriola dumerili). This species holds great potential for the aquaculture industry, but in captivity, reproduction has proved to be challenging, and observed growth dysfunction hinders their domestication. Insights into molecular mechanisms may contribute to a better understanding of traits like growth and sex, but investigations to unravel the molecular background of amberjacks have begun only recently. Findings: Illumina HiSeq sequencing generated a high-coverage greater amberjack genome sequence comprising 45 909 scaffolds. Comparative mapping to the Japanese yellowtail (Seriola quinqueriadiata) and to the model species medaka (Oryzias latipes) allowed the generation of in silico groups. Additional gonad transcriptome sequencing identified sex-biased transcripts, including known sex-determining and differentiation genes. Investigation of the muscle transcriptome of slow-growing individuals showed that transcripts involved in oxygen and gas transport were differentially expressed compared with fast/normal-growing individuals. On the other hand, transcripts involved in muscle functions were found to be enriched in fast/normal-growing individuals. Conclusion: The present study provides the first insights into the molecular background of male and female amberjacks and of fast- and slow-growing fish. Therefore, valuable molecular resources have been generated in the form of a first draft genome and a reference transcriptome. Sex-biased genes, which may also have roles in sex determination or differentiation, and genes that may be responsible for slow growth are suggested. © The Author(s) 2017.},
note = {Publisher: Oxford University Press},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2016

Zohar, Y; Mylonas, C C; Rosenfeld, H; de la Gándara, F; Corriero, A

Reproduction, Broodstock Management, and Spawning in Captive Atlantic Bluefin Tuna Incollection

Benetti, DD; Partridge, GJ; Buentello, A (Ed.): Advances in Tuna Aquaculture - From Hatchery to Market, pp. 159–188, Elsevier Inc., 2016, ISBN: 978-0-12-411506-4 978-0-12-411459-3, (Publication Title: Advances in Tuna Aquaculture: From Hatchery to Market).

Abstract | Links | BibTeX

@incollection{zohar_reproduction_2016,
title = {Reproduction, Broodstock Management, and Spawning in Captive Atlantic Bluefin Tuna},
author = {Y Zohar and C C Mylonas and H Rosenfeld and F de la Gándara and A Corriero},
editor = {DD Benetti and GJ Partridge and A Buentello},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006186625&doi=10.1016%2fB978-0-12-411459-3.00006-0&partnerID=40&md5=62c4fb5ea1169f490010e4d650393501},
doi = {10.1016/B978-0-12-411459-3.00006-0},
isbn = {978-0-12-411506-4 978-0-12-411459-3},
year = {2016},
date = {2016-01-01},
booktitle = {Advances in Tuna Aquaculture - From Hatchery to Market},
pages = {159--188},
publisher = {Elsevier Inc.},
abstract = {Understanding the reproductive biology of Atlantic bluefin tuna (ABFT) is important to both managing its fishery and developing hatchery technologies to close its life cycle in aquaculture. Globally, ABFT is comprised of two populations, the eastern and western stocks, with known breeding areas in the Mediterranean Sea and the Gulf of Mexico, respectively. Gametogenesis takes place during spring and early summer, and spawning usually occurs from May to July, coinciding with the rise of water temperature. Females display an asynchronous ovarian development, typical of a batch spawner. Comparing the endocrine-reproductive cycle in wild and captive ABFT led to the development of a hormone-based therapy to induce spawning in captive broodstock. While captivity affects gametogenesis in ABFT, at least some of the captive fish spawn spontaneously, which can be enhanced and prolonged using hormonal induction. Massive spawning of captive ABFT enabled the first aquaculture production of marketable fish, demonstrating the biological feasibility of this industry. Current research on hormonal regulation of its puberty may lead to the use of smaller ABFT broodstock, simplifying their husbandry and management. This, together with the establishment of land-based broodstock operations, will enable efficient and cost-effective on-demand and year-round production of ABFT seeds to drive the consistent farming of this fish. © 2016 Elsevier Inc. All rights reserved.},
note = {Publication Title: Advances in Tuna Aquaculture: From Hatchery to Market},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}

Mylonas, C C; Salone, S; Biglino, T; de Mello, P H; Fakriadis, I; Sigelaki, I; Duncan, N

Enhancement of oogenesis/spermatogenesis in meagre Argyrosomus regius using a combination of temperature control and GnRHa treatments Journal Article

Aquaculture, 464 , pp. 323–330, 2016, ISSN: 00448486, (Publisher: Elsevier B.V.).

Abstract | Links | BibTeX

@article{mylonas_enhancement_2016,
title = {Enhancement of oogenesis/spermatogenesis in meagre Argyrosomus regius using a combination of temperature control and GnRHa treatments},
author = {C C Mylonas and S Salone and T Biglino and P H de Mello and I Fakriadis and I Sigelaki and N Duncan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978193838&doi=10.1016%2fj.aquaculture.2016.07.006&partnerID=40&md5=33e0a7321455743f1b6c84fcc8aedb38},
doi = {10.1016/j.aquaculture.2016.07.006},
issn = {00448486},
year = {2016},
date = {2016-01-01},
journal = {Aquaculture},
volume = {464},
pages = {323--330},
abstract = {A multiple GnRHa injection method for inducing spawning of high fecundity and quality in meagre was optimized. Specifically, the study (a) examined how long females would continue spawning in response to consecutive, weekly GnRHa injections, if maintained at the natural spawning temperature, and (b) evaluated whether males can produce adequate amounts of good quality sperm for the same period, with the assistance of a GnRHa therapy. Combined with stable temperatures (19–20 °C) that are prevalent during the early spawning season (April–May) in the Mediterranean Sea, each weekly GnRHa injection induced 2 consecutive spawns per week for a period of 17 weeks. Fish spawned consistently 2 days after treatment and produced high fecundity and egg quality (i.e. fertilization, hatching and early larval development). Maximum mean total fecundity (± S.D.) obtained was 1,415,000 ± 149,000 eggs kg− 1 in 32 spawns, being the highest total season fecundity reported for meagre, and significantly higher than the estimated maximum potential fecundity for the species. At the same time, sperm of consistently high quality (i.e. initial motility, duration of motility and storage survival) was produced in response to treatment with multiple GnRHa implants, though towards the end of the experiment a significant reduction (ANOVA, P ≤ 0.05) in spermatozoa density was observed. This protocol is expected to enhance greatly commercial production of meagre. Statement of relevance The present study reports on an optimized protocol for the induction of consistent and repeated spawning in meagre, based on the use of weekly GnRHa injections combined with stable temperatures that are prevalent at the early spawning season in the Mediterranean Sea. This protocol produced eggs of high fecundity and quality (i.e. fertilization, hatching and early larval development) for a period of > 4 months, and it is expected to enhance greatly commercial production of meagre. © 2016},
note = {Publisher: Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Manousaki, Tereza; Tsakogiannis, Alexandros; Taggart, John B; Palaiokostas, Christos; Tsaparis, Dimitris; Lagnel, Jacques; Chatziplis, Dimitrios; Magoulas, Antonios; Papandroulakis, Nikos; Mylonas, Constantinos C; TSIGENOPOULOS, C S

Exploring a nonmodel teleost genome through rad sequencing—linkage mapping in Common Pandora, Pagellus erythrinus and comparative genomic analysis Journal Article

G3: Genes, genomes, genetics, 6 (3), pp. 509–519, 2016, (Publisher: G3: Genes, Genomes, Genetics).

BibTeX

2015

Mylonas, C C; Fatira, E; Karkut, P; Papadaki, M; Sigelaki, I; Duncan, N J

Reproduction of hatchery-produced meagre Argyrosomus regius in captivity III. Comparison between GnRHa implants and injections on spawning kinetics and egg/larval performance parameters Journal Article

Aquaculture, 448 , pp. 44–53, 2015, ISSN: 00448486, (Publisher: Elsevier).

Abstract | Links | BibTeX

@article{mylonas_reproduction_2015,
title = {Reproduction of hatchery-produced meagre Argyrosomus regius in captivity III. Comparison between GnRHa implants and injections on spawning kinetics and egg/larval performance parameters},
author = {C C Mylonas and E Fatira and P Karkut and M Papadaki and I Sigelaki and N J Duncan},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930649334&doi=10.1016%2fj.aquaculture.2015.05.036&partnerID=40&md5=166818b9c8f787751aa632ac652d6bb1},
doi = {10.1016/j.aquaculture.2015.05.036},
issn = {00448486},
year = {2015},
date = {2015-01-01},
journal = {Aquaculture},
volume = {448},
pages = {44--53},
abstract = {Hatchery-produced meagre (Argyrosomus regius) were induced to spawn using either controlled-release delivery systems (implants) loaded with gonadotropin-releasing hormone agonist (GnRHa) or GnRHa injections. Over two consecutive years, individual females were paired with single males after treatment with a GnRHa implant (40-104μgkg-1) or a GnRHa injection (15-25μgkg-1). Three consecutive GnRHa implants were given every 20-30days, while five (in 2012) or seven (in 2013) consecutive GnRHa injections were given every 10days. Fecundity and fertilization success was evaluated the day of spawning, and embryo/larval development was evaluated using 96-well microtiter plates. The first implantation with GnRHa produced up to 23 almost daily spawns, but most females failed to spawn repeatedly after the second implantation, even though their ovaries contained significant numbers of post-vitellogenic oocytes. Most of the eggs were produced in the first 3-4 spawns after GnRHa implantation, while the remaining batches were of low fecundity, which related directly to low fertilization. On the other hand, GnRHa injections produced consistently two spawns on days 2 and 3 after each treatment. Fecundity also decreased over time in response to the subsequent injections, but the response was more gradual and less dramatic than in GnRHa implanted females. Although both methods produced similar overall results in terms of total fecundity and egg/larval quality, multiple GnRHa injections resulted in more consistent spawning results and better egg production control, and this method may offer significant advantages over the use of controlled-release GnRHa implants. Statement of relevance: We present an efficient spawning induction method for meagre, which is the result of extensive experimentation both in previously published works, as well as in this one. The resulting method is proposed for its effectiveness and efficiency to the aquaculture industry. © 2015 Elsevier B.V..},
note = {Publisher: Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Manousaki, T; Tsakogiannis, A; Taggart, B J; Chatziplis, D; Mylonas, C C; Tsigenopoulos, C S

Linkage mapping in common pandora, Pagellus erythrinus, using ddRAD methodology Inproceedings

11th Panhellenic Symposium on Oceanography and Fisheries, pp. 69–72, Mytilene, Lesvos island, Greece, 2015, ISBN: 978-960-9798-08-2.

Abstract | BibTeX

2014

Tsigenopoulos, C S; Louro, B; Chatziplis, D; Lagnel, J; Vogiatzi, E; Loukovitis, D; Franch, R; Sarropoulou, E; Power, D M; Patarnello, T; Mylonas, C C; Magoulas, A; Bargelloni, L; Canario, A; Kotoulas, G

Second generation genetic linkage map for the gilthead sea bream Sparus aurata L. Journal Article

Marine Genomics, 18 (PA), pp. 77–82, 2014, ISSN: 18747787, (Publisher: Elsevier B.V.).

Abstract | Links | BibTeX

@article{tsigenopoulos_second_2014,
title = {Second generation genetic linkage map for the gilthead sea bream Sparus aurata L.},
author = {C S Tsigenopoulos and B Louro and D Chatziplis and J Lagnel and E Vogiatzi and D Loukovitis and R Franch and E Sarropoulou and D M Power and T Patarnello and C C Mylonas and A Magoulas and L Bargelloni and A Canario and G Kotoulas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922896860&doi=10.1016%2fj.margen.2014.09.008&partnerID=40&md5=c3bdc2b59c298f1c4d2cf093183db7ab},
doi = {10.1016/j.margen.2014.09.008},
issn = {18747787},
year = {2014},
date = {2014-01-01},
journal = {Marine Genomics},
volume = {18},
number = {PA},
pages = {77--82},
abstract = {An updated second linkage map was constructed for the gilthead sea bream, Sparus aurata L., a fish species of great economic importance for the Mediterranean aquaculture industry. In contrast to the first linkage map which mainly consisted of genomic microsatellites (SSRs), the new linkage map is highly enriched with SSRs found in Expressed Sequence Tags (EST-SSRs), which greatly facilitates comparative mapping with other teleosts. The new map consists of 321 genetic markers in 27 linkage groups (LGs): 232 genomic microsatellites, 85 EST-SSRs and 4 SNPs; of those, 13 markers were linked to LGs but were not ordered. Eleven markers (5 SSRs, 5 EST-SSRs and 1 SNP) are not assigned to any LG. The total length of the sex-averaged map is 1769.7. cM, 42% longer than the previously published one, and the number of markers in each LG ranges from 2 to 30. The inter-marker distance varies from 0 to 75.6. cM, with an average of 5.75. cM. The male and female maps have a length of 1349.2 and 2172.1. cM, respectively, and the average distance between markers is 4.38 and 7.05. cM, respectively. Comparative mapping with the three-spined stickleback (Gasterosteus acuulatus) chromosomes and scaffolds showed conserved synteny with 132 S. aurata markers (42.9% of those mapped) having a hit on the stickleback genome. © 2014 Elsevier B.V.},
note = {Publisher: Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Zupa, R; Santamaria, N; Mylonas, C C; Deflorio, M; de la Gándara, F; Vassallo-Agius, R; Pousis, C; Passantino, L; Centoducati, G; Bello, G; Corriero, A

Male germ cell proliferation and apoptosis during the reproductive cycle of captive-reared Atlantic bluefin tuna Thunnus thynnus (Linnaeus) Journal Article

Aquaculture Research, 45 (10), pp. 1733–1736, 2014, ISSN: 1355557X, (Publisher: Blackwell Publishing Ltd).

Links | BibTeX

Manousaki, Tereza; Tsakogiannis, Alexandros; Lagnel, Jacques; Sarropoulou, Elena; Xiang, Jenny Z; Papandroulakis, Nikos; Mylonas, Constantinos C; Tsigenopoulos, Costas S

The sex-specific transcriptome of the hermaphrodite sparid sharpsnout seabream (Diplodus puntazzo) Journal Article

BMC genomics, 15 (1), pp. 655, 2014, (Publisher: BioMed Central).

BibTeX

2013

Berkovich, N; Meiri-Ashkenazi, I; Zlatnikov, V; Corriero, A; Bridges, C; Mylonas, C; Vassallo, Aguis R; Gándara, De La F; Belmonte, A; Elizur, A; Gordin, H; Rosenfeld, H

The key neuroendocrine regulators of the onset of puberty in the Atlantic bluefin tuna (Thunnus thynnus). Journal Article

Communications in agricultural and applied biological sciences, 78 (4), pp. 39–40, 2013, ISSN: 13791176.

Links | BibTeX

Berkovich, N; Corriero, A; Santamaria, N; Mylonas, C C; Vassallo-Aguis, R; de la Gándara, F; Meiri-Ashkenazi, I; Zlatnikov, V; Gordin, H; Bridges, C R; Rosenfeld, H

Intra-pituitary relationship of follicle stimulating hormone and luteinizing hormone during pubertal development in Atlantic bluefin tuna (Thunnus thynnus) Journal Article

General and Comparative Endocrinology, 194 , pp. 10–23, 2013, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{berkovich_intra-pituitary_2013,
title = {Intra-pituitary relationship of follicle stimulating hormone and luteinizing hormone during pubertal development in Atlantic bluefin tuna (Thunnus thynnus)},
author = {N Berkovich and A Corriero and N Santamaria and C C Mylonas and R Vassallo-Aguis and F de la Gándara and I Meiri-Ashkenazi and V Zlatnikov and H Gordin and C R Bridges and H Rosenfeld},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884387351&doi=10.1016%2fj.ygcen.2013.08.005&partnerID=40&md5=d801f47f275901c69e8e871ecb39bc98},
doi = {10.1016/j.ygcen.2013.08.005},
issn = {00166480},
year = {2013},
date = {2013-01-01},
journal = {General and Comparative Endocrinology},
volume = {194},
pages = {10--23},
abstract = {As part of the endeavor aiming at the domestication of Atlantic bluefin tuna (BFT; Thunnus thynnus), first sexual maturity in captivity was studied by documenting its occurrence and by characterizing the key hormones of the reproductive axis: follicle stimulating hormone (FSH) and luteinizing hormone (LH). The full length sequence encoding for the related hormone β-subunits, bftFSHβ and bftLHβ, were determined, revealing two bftFSHβ mRNA variants, differing in their 5' untranslated region.A quantitative immuno-dot-blot assay to measure pituitary FSH content in BFT was developed and validated enabling, for the first time in this species, data sets for both LH and FSH to be compared. The expression and accumulation patterns of LH in the pituitary showed a steady increase of this hormone, concomitant with fish age, reaching higher levels in adult females compared to males of the same age class. Conversely, the pituitary FSH levels were elevated only in 2Y and adult fish. The pituitary FSH to LH ratio was consistently higher (textgreater1) in immature than in maturing or pubertal fish, resembling the situation in mammals. Nevertheless, the results suggest that a rise in the LH storage level above a minimum threshold may be an indicator of the onset of puberty in BFT females. The higher pituitary LH levels in adult females over males may further support this notion.In contrast three year-old (3Y) males were pubertal while cognate females were still immature. However, it is not yet clear whether the advanced puberty in the 3Y males was a general feature typifying wild BFT populations or was induced by the culture conditions. Future studies testing the effects of captivity and hormonal treatments on precocious maturity may allow for improved handling of this species in a controlled environment which would lead to more cost-efficient farming. © 2013 Elsevier Inc.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Papadakis, I E; Kentouri, M; Divanach, P; Mylonas, C C

Ontogeny of the digestive system of meagre Argyrosomus regius reared in a mesocosm, and quantitative changes of lipids in the liver from hatching to juvenile Journal Article

Aquaculture, 388-391 (1), pp. 76–88, 2013, ISSN: 00448486, (Publisher: Elsevier B.V.).

Abstract | Links | BibTeX

@article{papadakis_ontogeny_2013,
title = {Ontogeny of the digestive system of meagre Argyrosomus regius reared in a mesocosm, and quantitative changes of lipids in the liver from hatching to juvenile},
author = {I E Papadakis and M Kentouri and P Divanach and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873700252&doi=10.1016%2fj.aquaculture.2013.01.012&partnerID=40&md5=f4c62c1417bb80d113e957f7d9a763ac},
doi = {10.1016/j.aquaculture.2013.01.012},
issn = {00448486},
year = {2013},
date = {2013-01-01},
journal = {Aquaculture},
volume = {388-391},
number = {1},
pages = {76--88},
abstract = {Histological development of the digestive systemwas studied in association with feeding preferences in meagre (Argyrosomus regius) fromhatching to juvenile (44 days after hatching, dah), using amesocosmsystem. In addition, the liver lipid content was evaluated using histological methods (area covered with lipid vacuoles, ACLV%). The ontogeny of the digestive system was completed by 19 dah (or 444 degree days) with the gastric glands appearing at 15 dah (361 degree days), the pyloric ceaca at 17 dah (404 degree days) and the Y-shaped stomach formed at 19 dah (444 degree days). The rearing period was characterized first by relatively slow growth until tail flexion ( 15 dah) and fast growth thereafter (mean±SD total length of 45.14±4.00 mm at 44 dah). When the feeding protocol included exclusively rotifers, mean ACLV remained low (2.39±0.34%) while feeding on Artemia nauplii and copepods increased liver ACLV to 47.18±6.56% at 20 dah. Changes in the feeding protocol were reflected in feeding preferences (stomach content), and variations of liver lipid content and the occurrence of vacuoles in the intestine. During transition from live prey to artificial feed ( 28 dah), ACLV decreased significantly - indicating amalnutrition period - concomitantwith a delay in the acceptance of artificial feed of 8 days. Thereafter, consumption of artificial feed resulted in an increased ACLV to 56.3±7.6% at 36 dah. The results indicate that during early development meagre is a fast growing species, developing rapidly the structures and basic organs of the digestive system required to overcome successfully the critical stages of larval rearing. The study also shows that histological evaluation of liver lipid content using the ACLV may be a valuable tool incommercial aquaculture to improve larval rearing protocols, and production efficiency. © 2013 Elsevier B.V.},
note = {Publisher: Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Zupa, R; Fauvel, C; Mylonas, C C; Santamaria, N; Valentini, L; Pousis, C; Papadaki, M; Suquet, M; la Gándara, De F; Bello, G; Metrio, De G; Corriero, A

Comparative analysis of male germ cell proliferation and apoptosis in wild and captive Atlantic bluefin tuna (Thunnus thynnus L.) Journal Article

Journal of Applied Ichthyology, 29 (1), pp. 71–81, 2013, ISSN: 01758659.

Abstract | Links | BibTeX

@article{zupa_comparative_2013,
title = {Comparative analysis of male germ cell proliferation and apoptosis in wild and captive Atlantic bluefin tuna (Thunnus thynnus L.)},
author = {R Zupa and C Fauvel and C C Mylonas and N Santamaria and L Valentini and C Pousis and M Papadaki and M Suquet and F De la Gándara and G Bello and G De Metrio and A Corriero},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872311647&doi=10.1111%2fj.1439-0426.2012.02045.x&partnerID=40&md5=286c3d6def7c6fa6ee4d801b0c86665c},
doi = {10.1111/j.1439-0426.2012.02045.x},
issn = {01758659},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Ichthyology},
volume = {29},
number = {1},
pages = {71--81},
abstract = {The most commonly observed reproductive dysfunction in male fishes reared in captivity is reduction in sperm volume and quality. The Atlantic bluefin tuna Thunnus thynnus (Osteichthyes: Scombridae) is one of the few large pelagic and migratory marine fishes maintained in captivity with the purpose of establishing breeding populations to support an aquaculture industry. The objectives of the present study were to compare male germ cell proliferation and apoptosis between wild and captive individuals at two different phases of the spermatogenetic cycle, and to evaluate sperm motility characteristics of captive individuals. Histological observations were performed to analyze testicular activity, and germ cell proliferation and apoptosis were evaluated through the immunohistochemical detection of proliferating cell nuclear antigen (PCNA) and the terminal deoxynucleotidyl transferasemediated d'UTP nick end labeling (TUNEL) method, respectively. Computer-assisted sperm analysis (CASA) was used to evaluate sperm motility. Results showed that germ cell proliferation was delayed and germ cell apoptosis increased in captive animals relative to wild individuals. Sperm motility of samples obtained from captive individuals was anomalous, both in terms of motility duration and swimming efficiency. Thus it appears that rearing in captivity impairs male reproductive function through, at least, changes in germ cell proliferation and apoptosis. © 2012 Blackwell Verlag GmbH.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Sfakianakis, D G; Papadakis, I E; Papadaki, M; Sigelaki, I; Mylonas, C C

Influence of rearing temperature during early life on sex differentiation, haemal lordosis and subsequent growth during the whole production cycle in European sea bass Dicentrarchus labrax Journal Article

Aquaculture, 412-413 , pp. 179–185, 2013, ISSN: 00448486.

Abstract | Links | BibTeX

@article{sfakianakis_influence_2013,
title = {Influence of rearing temperature during early life on sex differentiation, haemal lordosis and subsequent growth during the whole production cycle in European sea bass Dicentrarchus labrax},
author = {D G Sfakianakis and I E Papadakis and M Papadaki and I Sigelaki and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84881179660&doi=10.1016%2fj.aquaculture.2013.07.033&partnerID=40&md5=417cda13a14a81284d42c36155bb7bb9},
doi = {10.1016/j.aquaculture.2013.07.033},
issn = {00448486},
year = {2013},
date = {2013-01-01},
journal = {Aquaculture},
volume = {412-413},
pages = {179--185},
abstract = {The present study examined the influence of early-rearing temperature-which favors the development of male-dominant or female-dominant populations-in European sea bass Dicentrarchus labrax on haemal lordosis and growth performance until harvest time (mean body weight textgreater 400. g). European sea bass were reared at 15 or 20. °C from egg to metamorphosis ( . 17. mm in total length), which lasted for 66 and 55. days post spawning (dps), or 990 and 1100. °C-days, respectively. Thereafter, rearing until harvest time (715. dps) followed a common temperature regime, ranging between 14.5. °C in February and 26.5. °C in August. As expected from previous studies, the effect of early-life rearing temperature was significant on mean (± SEM) sex ratio (78 ± 2% females at 15. °C vs. 29 ± 2% females at 20. °C) and there was a highly significant (P textless 0.01) growth advantage in favor of the 20. °C fish at the end of the first year. However, there was no significant difference in body weight between the two temperature groups by harvest time, indicating the expression of compensatory growth in the 15. °C group. The mean occurrence of haemal lordosis incidence was evaluated using X-rays at the end of the nursery phase (145. dps) and was shown to be significantly higher in the 20. °C group (90 ± 0.4%) compared to the 15. °C group (41 ± 0.8%). The occurrence of haemal lordosis upon external image evaluation at harvest time decreased to 0% in the 15. °C group compared to 36 ± 7% in the 20. °C group. Almost half of these latter fish with haemal lordosis were considered unmarketable due to heavy deformation. These findings demonstrated that rearing European sea bass at low temperatures during early life can result in significant gains for aquaculture industry, through increases in female proportion-and therefore growth performance-and reductions in skeletal abnormalities. The study also demonstrated that even fish with heavy haemal lordosis could grow as well as normal fish, thus competing for food with normal fish and resulting in financial loss for the industry due to their unmarketability. © 2013 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The present study examined the influence of early-rearing temperature-which favors the development of male-dominant or female-dominant populations-in European sea bass Dicentrarchus labrax on haemal lordosis and growth performance until harvest time (mean body weight textgreater 400. g). European sea bass were reared at 15 or 20. °C from egg to metamorphosis ( . 17. mm in total length), which lasted for 66 and 55. days post spawning (dps), or 990 and 1100. °C-days, respectively. Thereafter, rearing until harvest time (715. dps) followed a common temperature regime, ranging between 14.5. °C in February and 26.5. °C in August. As expected from previous studies, the effect of early-life rearing temperature was significant on mean (± SEM) sex ratio (78 ± 2% females at 15. °C vs. 29 ± 2% females at 20. °C) and there was a highly significant (P textless 0.01) growth advantage in favor of the 20. °C fish at the end of the first year. However, there was no significant difference in body weight between the two temperature groups by harvest time, indicating the expression of compensatory growth in the 15. °C group. The mean occurrence of haemal lordosis incidence was evaluated using X-rays at the end of the nursery phase (145. dps) and was shown to be significantly higher in the 20. °C group (90 ± 0.4%) compared to the 15. °C group (41 ± 0.8%). The occurrence of haemal lordosis upon external image evaluation at harvest time decreased to 0% in the 15. °C group compared to 36 ± 7% in the 20. °C group. Almost half of these latter fish with haemal lordosis were considered unmarketable due to heavy deformation. These findings demonstrated that rearing European sea bass at low temperatures during early life can result in significant gains for aquaculture industry, through increases in female proportion-and therefore growth performance-and reductions in skeletal abnormalities. The study also demonstrated that even fish with heavy haemal lordosis could grow as well as normal fish, thus competing for food with normal fish and resulting in financial loss for the industry due to their unmarketability. © 2013 Elsevier B.V.

Mylonas, C C; Mitrizakis, N; Papadaki, M; Sigelaki, I

Reproduction of hatchery-produced meagre Argyrosomus regius in captivity I. Description of the annual reproductive cycle Journal Article

Aquaculture, 414-415 , pp. 309–317, 2013, ISSN: 00448486.

Abstract | Links | BibTeX

@article{mylonas_reproduction_2013,
title = {Reproduction of hatchery-produced meagre Argyrosomus regius in captivity I. Description of the annual reproductive cycle},
author = {C C Mylonas and N Mitrizakis and M Papadaki and I Sigelaki},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84886398444&doi=10.1016%2fj.aquaculture.2013.09.009&partnerID=40&md5=fc22bf7e18df3784b789a65fb143610b},
doi = {10.1016/j.aquaculture.2013.09.009},
issn = {00448486},
year = {2013},
date = {2013-01-01},
journal = {Aquaculture},
volume = {414-415},
pages = {309--317},
abstract = {The aim of the present study was to monitor the reproductive cycle of a hatchery-produced meagre Argyrosomus regius broodstock. Four-year-old fish of a mean weight (±SD) of 5.1±1.1kg for females (n=7) and 4.6±0.7kg for males (n=6), were maintained under simulated natural photo-thermal regime and sampled between November 2010 and July 2011. Vitellogenesis began in March, when the first increase in oocyte diameter was observed. Fully vitellogenic oocytes of mean (±SEM) diameter between 561±23 and 621±9μm were observed between April and June. Two of the seven females spawned spontaneously in June, producing six major spawns of 390,000-940,000 eggs per day with fertilization success >97%. Vitellogenesis was associated with relatively low levels of testosterone (T) ranging between mean values of 0.036±0.01ngml-1 and 0.207±0.07ngml-1, and of 17β-estradiol (E2) ranging between mean values of 0.194±0.09ngml-1 and 0.473±0.12ngml-1. Spermiation also began in March, but only 33% of the fish produced significant amounts of milt to allow sperm quality evaluations. In May 100% of the fish were spermiating, and in July spermiation ceased almost completely. No significant changes were observed during the spermiation period (March-June) in sperm concentration (mean ranged between 18.9 and 31.5×109szoaml-1) or initial sperm motility (mean ranged between 44 and 80%). The mean duration of motility (mean ranged between 0.78 and 1.27min) was also stable during the reproductive season, with the exception of a significant decrease in May. Mean plasma T and 11-ketotestosterone (11-KT) levels in male meagre increased gradually during the year, reaching their spermiation season peaks in March (0.818ng11-KTml-1) or in May (0.263ngTml-1). The study demonstrated that gametogenesis proceeds normally in hatchery-produced meagre and under the influence of relatively low levels of sex steroid hormones. Although spontaneous spawning was observed for the first time in meagre maintained in captivity (2 of 7 females), the study demonstrated also that oocyte maturation is sporadic and inconsistent, and reliable spawning could be obtained using only exogenous hormones. Furthermore, it was shown that females failing to undergo oocyte maturation, maintain their vitellogenic oocytes in a viable condition without significant atresia for a period of at least 2months (April-June). These oocytes could potentially be induced to undergo maturation, ovulation and spawning at any time during this "post-vitellogenesis" period. © 2013 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The aim of the present study was to monitor the reproductive cycle of a hatchery-produced meagre Argyrosomus regius broodstock. Four-year-old fish of a mean weight (±SD) of 5.1±1.1kg for females (n=7) and 4.6±0.7kg for males (n=6), were maintained under simulated natural photo-thermal regime and sampled between November 2010 and July 2011. Vitellogenesis began in March, when the first increase in oocyte diameter was observed. Fully vitellogenic oocytes of mean (±SEM) diameter between 561±23 and 621±9μm were observed between April and June. Two of the seven females spawned spontaneously in June, producing six major spawns of 390,000-940,000 eggs per day with fertilization success >97%. Vitellogenesis was associated with relatively low levels of testosterone (T) ranging between mean values of 0.036±0.01ngml-1 and 0.207±0.07ngml-1, and of 17β-estradiol (E2) ranging between mean values of 0.194±0.09ngml-1 and 0.473±0.12ngml-1. Spermiation also began in March, but only 33% of the fish produced significant amounts of milt to allow sperm quality evaluations. In May 100% of the fish were spermiating, and in July spermiation ceased almost completely. No significant changes were observed during the spermiation period (March-June) in sperm concentration (mean ranged between 18.9 and 31.5×109szoaml-1) or initial sperm motility (mean ranged between 44 and 80%). The mean duration of motility (mean ranged between 0.78 and 1.27min) was also stable during the reproductive season, with the exception of a significant decrease in May. Mean plasma T and 11-ketotestosterone (11-KT) levels in male meagre increased gradually during the year, reaching their spermiation season peaks in March (0.818ng11-KTml-1) or in May (0.263ngTml-1). The study demonstrated that gametogenesis proceeds normally in hatchery-produced meagre and under the influence of relatively low levels of sex steroid hormones. Although spontaneous spawning was observed for the first time in meagre maintained in captivity (2 of 7 females), the study demonstrated also that oocyte maturation is sporadic and inconsistent, and reliable spawning could be obtained using only exogenous hormones. Furthermore, it was shown that females failing to undergo oocyte maturation, maintain their vitellogenic oocytes in a viable condition without significant atresia for a period of at least 2months (April-June). These oocytes could potentially be induced to undergo maturation, ovulation and spawning at any time during this "post-vitellogenesis" period. © 2013 Elsevier B.V.

Mylonas, C C; Mitrizakis, N; Castaldo, C A; Cerviño, C P; Papadaki, M; Sigelaki, I

Reproduction of hatchery-produced meagre Argyrosomus regius in captivity II. Hormonal induction of spawning and monitoring of spawning kinetics, egg production and egg quality Journal Article

Aquaculture, 414-415 , pp. 318 – 327, 2013.

Abstract | Links | BibTeX

@article{mylonas_reproduction_2013-1,
title = {Reproduction of hatchery-produced meagre Argyrosomus regius in captivity II. Hormonal induction of spawning and monitoring of spawning kinetics, egg production and egg quality},
author = {C C Mylonas and N Mitrizakis and C A Castaldo and C P Cerviño and M Papadaki and I Sigelaki},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84886377596&partnerID=40&md5=237d527a7e2831d820e80c1868708b9d},
year = {2013},
date = {2013-01-01},
journal = {Aquaculture},
volume = {414-415},
pages = {318 -- 327},
abstract = {The present study aimed at the development of an effective and efficient hormonal spawning induction method for meagre Argyrosomus regius, using controlled-release delivery systems loaded with gonadotropin-releasing hormone agonist (GnRHa). Three sets of spawning induction experiments were undertaken in the course of three years. In experiment 1, group spawnings were performed at different times during the reproductive period, in order to determine the most appropriate time for hormonal induction of spawning. Experiment 2 described in more detail the spawning kinetics of individual females induced to spawn at different times during the season, in order to obtain important information on spawning kinetics, batch fecundity and total fecundity in response to the hormonal treatment. In experiment 3, two similar broodstocks were used to obtain further production characteristics and monitor variations in egg/larval quality over the spawning period. The effective GnRHa doses used were 55-84μgGnRHakg-1 body weight in males and 46-92μgGnRHakg-1 in females. In general, successful spawning induction was achieved between early May and early June. Implantation with GnRHa induced spawning 2-3d after treatment and produced an average (±SD) of 12±5 spawns per broodstock or female over 3weeks, most of them over consecutive days. Batch fecundity was extremely variable (mean of 6631 to 104,409eggskg-1), with the largest batches occurring 3-4d after treatment, and very low fecundity after 1week from GnRHa treatment. As a result, the first 4 spawns of all spawning induction experiments constituted a mean of 75±13% of the total relative fecundity. Overall mean total relative fecundity was variable at 380,780±167,577eggskg-1. Evaluation of the ovaries after the cessation of spawning, demonstrated that the females still contained large numbers of oocytes in full vitellogenesis, and it is hypothesized that these fish could spawn further in response to a second GnRHa implantation. Fertilization success was very high in all spawning induction experiments, with the overall mean being 89±5%. Similarly, the produced eggs were of very high quality, based on the survival of the eggs during embryogenesis (>95%), hatching success (>99%) and larval survival 5d after egg collection (>87%), resulting in an overall larva survival of 73% of the total number of eggs spawned. These studies demonstrate that the GnRHa implants are an effective and efficient method for the induction of spawning in meagre, leading to the production of eggs of high fecundity and quality. © 2013 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The present study aimed at the development of an effective and efficient hormonal spawning induction method for meagre Argyrosomus regius, using controlled-release delivery systems loaded with gonadotropin-releasing hormone agonist (GnRHa). Three sets of spawning induction experiments were undertaken in the course of three years. In experiment 1, group spawnings were performed at different times during the reproductive period, in order to determine the most appropriate time for hormonal induction of spawning. Experiment 2 described in more detail the spawning kinetics of individual females induced to spawn at different times during the season, in order to obtain important information on spawning kinetics, batch fecundity and total fecundity in response to the hormonal treatment. In experiment 3, two similar broodstocks were used to obtain further production characteristics and monitor variations in egg/larval quality over the spawning period. The effective GnRHa doses used were 55-84μgGnRHakg-1 body weight in males and 46-92μgGnRHakg-1 in females. In general, successful spawning induction was achieved between early May and early June. Implantation with GnRHa induced spawning 2-3d after treatment and produced an average (±SD) of 12±5 spawns per broodstock or female over 3weeks, most of them over consecutive days. Batch fecundity was extremely variable (mean of 6631 to 104,409eggskg-1), with the largest batches occurring 3-4d after treatment, and very low fecundity after 1week from GnRHa treatment. As a result, the first 4 spawns of all spawning induction experiments constituted a mean of 75±13% of the total relative fecundity. Overall mean total relative fecundity was variable at 380,780±167,577eggskg-1. Evaluation of the ovaries after the cessation of spawning, demonstrated that the females still contained large numbers of oocytes in full vitellogenesis, and it is hypothesized that these fish could spawn further in response to a second GnRHa implantation. Fertilization success was very high in all spawning induction experiments, with the overall mean being 89±5%. Similarly, the produced eggs were of very high quality, based on the survival of the eggs during embryogenesis (>95%), hatching success (>99%) and larval survival 5d after egg collection (>87%), resulting in an overall larva survival of 73% of the total number of eggs spawned. These studies demonstrate that the GnRHa implants are an effective and efficient method for the induction of spawning in meagre, leading to the production of eggs of high fecundity and quality. © 2013 Elsevier B.V.

2012

Rosenfeld, H; Mylonas, C C; Bridges, C R; Heinisch, G; Corriero, A; Vassallo-Aguis, R; Medina, A; Belmonte, A; Garcia, A; la Gándara, De F; Fauvel, C; Metrio, De G; Meiri-Ashkenazi, I; Gordin, H; Zohar, Y

GnRHa-mediated stimulation of the reproductive endocrine axis in captive Atlantic bluefin tuna, Thunnus thynnus Journal Article

General and Comparative Endocrinology, 175 (1), pp. 55–64, 2012, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{rosenfeld_gnrha-mediated_2012,
title = {GnRHa-mediated stimulation of the reproductive endocrine axis in captive Atlantic bluefin tuna, Thunnus thynnus},
author = {H Rosenfeld and C C Mylonas and C R Bridges and G Heinisch and A Corriero and R Vassallo-Aguis and A Medina and A Belmonte and A Garcia and F De la Gándara and C Fauvel and G De Metrio and I Meiri-Ashkenazi and H Gordin and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84855198528&doi=10.1016%2fj.ygcen.2011.09.013&partnerID=40&md5=74752a86f5a4e31386dea39f0cf4dea4},
doi = {10.1016/j.ygcen.2011.09.013},
issn = {00166480},
year = {2012},
date = {2012-01-01},
journal = {General and Comparative Endocrinology},
volume = {175},
number = {1},
pages = {55--64},
abstract = {A controlled-release implant loaded with GnRH agonist (GnRHa) was used to induce spawning in Atlantic bluefin tuna (Thunnus thynnus) during two consecutive reproductive seasons. The fish were implanted underwater and sampled between days 2 and 8 after treatment. At the time of GnRHa treatment, females were in full vitellogenesis and males in spermiation. There was a rapid burst of pituitary luteinizing hormone (LH) release at day 2 after treatment in GnRHa-treated fish, and circulating LH remained elevated up to day 8 after treatment. In contrast, control fish had significantly lower levels in the plasma, but higher LH content in the pituitary, as observed in many other cultured fishes that fail to undergo oocyte maturation, ovulation and spawning unless induced by an exogenous GnRHa. Plasma testosterone (T) and 17β-estradiol (E2) were elevated in response to the GnRHa treatment in females, while 11-ketotestosterone (11-KT) but not T was elevated in males. Even though oocyte maturation and ovulation did occur in GnRHa-induced fish, no significant elevations in 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) or 17,20β,21-trihydroxy-4-pregnen-3-one (20β-S), in either the free, conjugated or 5β-reduced,3α-hydroxylated forms was observed in fish sampled within 6days after treatment. Interestingly, a significant peak in plasma free 17,20β-P levels occurred in both males and females at day 8 after treatment. Histological sections of the ovaries in these females contained oocytes at the migrating germinal vesicle stage, suggesting the role of this hormone as a maturation-inducing steroid in Atlantic bluefin tuna.In conclusion, the GnRHa implants activated effectively the reproductive endocrine axis in captive Atlantic bluefin tuna broodstocks, through stimulation of sustained elevations in plasma LH, which in turn evoked the synthesis and secretion of the relevant sex steroids leading to gamete maturation and release. © 2011 Elsevier Inc.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Duncan, N; Estévez, A; Porta, J; Carazo, I; Norambuena, F; Aguilera, C; Gairin, I; Bucci, F; Valles, R; Mylonas, C C

Reproductive development, GnRHa-induced spawning and egg quality of wild meagre (Argyrosomus regius) acclimatised to captivity Journal Article

Fish Physiology and Biochemistry, 38 (5), pp. 1273–1286, 2012, ISSN: 09201742.

Abstract | Links | BibTeX

@article{duncan_reproductive_2012,
title = {Reproductive development, GnRHa-induced spawning and egg quality of wild meagre (Argyrosomus regius) acclimatised to captivity},
author = {N Duncan and A Estévez and J Porta and I Carazo and F Norambuena and C Aguilera and I Gairin and F Bucci and R Valles and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84866521589&doi=10.1007%2fs10695-012-9615-3&partnerID=40&md5=15b39d9920e00c0e4a3a4db4c38146fc},
doi = {10.1007/s10695-012-9615-3},
issn = {09201742},
year = {2012},
date = {2012-01-01},
journal = {Fish Physiology and Biochemistry},
volume = {38},
number = {5},
pages = {1273--1286},
abstract = {The objective of the study was to acclimatise wild-caught meagre (Argyrosomus regius) to captivity to produce viable eggs for aquaculture production. Twelve meagre (3 males and 9 females, mean weight = 20 ± 7 kg) were caught and transported to a land-based facility on 26 October 2006. During, March to June 2007, all three males were spermiating and five of the nine females were in vitellogenesis with mean maximum oocyte diameter ≥550 μm. No spontaneous spawning was observed. Two hormone treatments, either a single injection of gonadotropin-releasing hormone agonist (GnRHa, 20 μg kg-1 for females and 10 μg kg-1 for males) or a slow-release implant loaded with the same GnRHa (50 μg kg-1 for females and 25 μg kg-1 for males), were used to induce spawning on three different dates on 26 March 2007, 4 May 2007 and 18 April 2008. From each spawning event, the following parameters were determined: fecundity, number of floating eggs, egg size, fertilisation and hatching success, unfed larval survival, and proximal composition and fatty acid profile of the eggs. In 2007, two females that were injected on 26 March and 4 May spawned a total of 5 times producing 9,019,300 floating eggs and a relative fecundity of 198,200 eggs kg-1 and two different females that were implanted on the same dates spawned 14 times producing 12,430,000 floating eggs and a relative fecundity of 276,200 eggs kg-1. In 2008, a pair that was implanted spawned five times producing a total of 10,211,900 floating eggs and a relative fecundity of 527,380 eggs kg-1. The latency period was 48-72 h. Parameters were compared between hormone treatments, date of hormone induction and parents determined by microsatellites. Percentage hatch and egg size were 70 ± 0.3% and 0.99 ± 0.02 mm, respectively, for GnRHa-implanted fish and were significantly higher (P < 0.05) compared to 30 ± 0.3% and 0.95 ± 0.03 mm, respectively, for injected fish. Few differences were observed in proximal composition and fatty acid profile and for all spawns mean (% dry weight) lipid content was 17.3 ± 3.0%, carbohydrate was 4.4 ± 1.9% and protein was 31.5 ± 6.4% and the essential fatty acids: Arachidonic acid (ARA, 20:4n-6) ranged between 0.9 and 1% (of total fatty acids), eicosapentaenoic acid (EPA 20:5n-3) 7.7-10.4% and docosahexaenoic acid (DHA 22:6n-3), 28.6-35.4%. All good quality spawns were obtained in the second and/or third spawn after GnRHa treatment, whereas all bad quality spawns were obtained either on the first spawn or after the fifth spawn. Both spawning protocols gave commercially viable (1,000,000+) numbers of good quality eggs that could form the basis of a hatchery production. © 2012 Springer Science+Business Media B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The objective of the study was to acclimatise wild-caught meagre (Argyrosomus regius) to captivity to produce viable eggs for aquaculture production. Twelve meagre (3 males and 9 females, mean weight = 20 ± 7 kg) were caught and transported to a land-based facility on 26 October 2006. During, March to June 2007, all three males were spermiating and five of the nine females were in vitellogenesis with mean maximum oocyte diameter ≥550 μm. No spontaneous spawning was observed. Two hormone treatments, either a single injection of gonadotropin-releasing hormone agonist (GnRHa, 20 μg kg-1 for females and 10 μg kg-1 for males) or a slow-release implant loaded with the same GnRHa (50 μg kg-1 for females and 25 μg kg-1 for males), were used to induce spawning on three different dates on 26 March 2007, 4 May 2007 and 18 April 2008. From each spawning event, the following parameters were determined: fecundity, number of floating eggs, egg size, fertilisation and hatching success, unfed larval survival, and proximal composition and fatty acid profile of the eggs. In 2007, two females that were injected on 26 March and 4 May spawned a total of 5 times producing 9,019,300 floating eggs and a relative fecundity of 198,200 eggs kg-1 and two different females that were implanted on the same dates spawned 14 times producing 12,430,000 floating eggs and a relative fecundity of 276,200 eggs kg-1. In 2008, a pair that was implanted spawned five times producing a total of 10,211,900 floating eggs and a relative fecundity of 527,380 eggs kg-1. The latency period was 48-72 h. Parameters were compared between hormone treatments, date of hormone induction and parents determined by microsatellites. Percentage hatch and egg size were 70 ± 0.3% and 0.99 ± 0.02 mm, respectively, for GnRHa-implanted fish and were significantly higher (P < 0.05) compared to 30 ± 0.3% and 0.95 ± 0.03 mm, respectively, for injected fish. Few differences were observed in proximal composition and fatty acid profile and for all spawns mean (% dry weight) lipid content was 17.3 ± 3.0%, carbohydrate was 4.4 ± 1.9% and protein was 31.5 ± 6.4% and the essential fatty acids: Arachidonic acid (ARA, 20:4n-6) ranged between 0.9 and 1% (of total fatty acids), eicosapentaenoic acid (EPA 20:5n-3) 7.7-10.4% and docosahexaenoic acid (DHA 22:6n-3), 28.6-35.4%. All good quality spawns were obtained in the second and/or third spawn after GnRHa treatment, whereas all bad quality spawns were obtained either on the first spawn or after the fifth spawn. Both spawning protocols gave commercially viable (1,000,000+) numbers of good quality eggs that could form the basis of a hatchery production. © 2012 Springer Science+Business Media B.V.

Sfakianakis, D G; Leris, I; Mylonas, C C; Kentouri, M

Temperature during early life determines sex in zebrafish, Danio rerio (Hamilton, 1822) Journal Article

Journal of Biological Research, 17 , pp. 68–73, 2012, ISSN: 1790045X.

Abstract | Links | BibTeX

Pousis, C; Santamaria, N; Zupa, R; Giorgi, De C; Mylonas, C C; Bridges, C R; de la Gándara, F; Vassallo-Agius, R; Bello, G; Corriero, A

Expression of vitellogenin receptor gene in the ovary of wild and captive Atlantic bluefin tuna (Thunnus thynnus) Journal Article

Animal Reproduction Science, 132 (1-2), pp. 101–110, 2012, ISSN: 03784320.

Abstract | Links | BibTeX

@article{pousis_expression_2012,
title = {Expression of vitellogenin receptor gene in the ovary of wild and captive Atlantic bluefin tuna (Thunnus thynnus)},
author = {C Pousis and N Santamaria and R Zupa and C De Giorgi and C C Mylonas and C R Bridges and F de la Gándara and R Vassallo-Agius and G Bello and A Corriero},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861706609&doi=10.1016%2fj.anireprosci.2012.03.014&partnerID=40&md5=8e527b02fa02017762d5680cc734cde9},
doi = {10.1016/j.anireprosci.2012.03.014},
issn = {03784320},
year = {2012},
date = {2012-01-01},
journal = {Animal Reproduction Science},
volume = {132},
number = {1-2},
pages = {101--110},
abstract = {The cDNA sequences of vitellogenin receptor proteins (VgR + and VgR -), containing or lacking the O-linked sugar domain, were determined in Atlantic bluefin tuna (Thunnus thynnus L.). VgR - gene expression in the ovary was compared in captive-reared and wild Atlantic bluefin tuna during the reproductive cycle. Gonad samples from adult fish were sampled from 2008 to 2010 from stocks reared in captivity at different commercial fattening operations in the Mediterranean Sea and from wild individuals caught either by traditional tuna traps during their migration towards the spawning grounds in the Mediterranean Sea or by the long-line artisanal fishery. In addition, juvenile male and female Atlantic bluefin tuna were sampled from a farming facility, to obtain baseline information and pre-adulthood amounts of VgR -. The total length of VgR + cDNA was 4006 nucleotides (nt) and that of VgR - was 3946nt. Relative amounts of VgR - were greater in juvenile females and in those adults having only previtellogenic oocytes (119±55 and 146±26 folds more than juvenile males, respectively). Amounts of VgR - were less in individuals with yolked oocytes (ripening stage, May-June) and increased after spawning in July (92±20 and 113±13 folds more than juvenile males in ripening and post-spawning fish, respectively). These data suggest that regulation of VgR - is not under oestrogen control. During the ripening period, greater VgR - gene expression was observed in wild fish than in fish reared in captivity, possibly because of (a) differences in water temperature exposure and/or energy storage, and/or (b) an inadequate diet in reared Atlantic bluefin tuna. © 2012 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Alavi, S M H; Hatef, A; Mylonas, C C; Gela, D; Papadaki, M; Rodina, M; Kašpar, V; Pšenička, M; Podhorec, P; Linhart, O

Sperm characteristics and androgens in Acipenser ruthenus after induction of spermiation by carp pituitary extract or GnRHa implants Journal Article

Fish Physiology and Biochemistry, 38 (6), pp. 1655–1666, 2012, ISSN: 09201742.

Abstract | Links | BibTeX

@article{alavi_sperm_2012,
title = {Sperm characteristics and androgens in Acipenser ruthenus after induction of spermiation by carp pituitary extract or GnRHa implants},
author = {S M H Alavi and A Hatef and C C Mylonas and D Gela and M Papadaki and M Rodina and V Kašpar and M Pšenička and P Podhorec and O Linhart},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84869128817&doi=10.1007%2fs10695-012-9662-9&partnerID=40&md5=0dd912dc379a6d91d765f370b929505f},
doi = {10.1007/s10695-012-9662-9},
issn = {09201742},
year = {2012},
date = {2012-01-01},
journal = {Fish Physiology and Biochemistry},
volume = {38},
number = {6},
pages = {1655--1666},
abstract = {Spermiation and changes in androgen (testosterone, T and 11-ketotestosterone, 11-KT) levels were studied in sterlet (Acipenser ruthenus) treated with GnRH agonist implants (dAla6-Pro9-LHRHa) at 25 and 75 μg kg-1 b. w. and compared with those males treated with 4 mg kg-1 b. w. of carp pituitary extract (CPE) and 3 pellets of Ovopel kg-1 b. w., which contains dAla6-Pro9NEt-mGnRH and metoclopramide. Sperm quality (sperm mass, spermatozoa concentration and sperm motility and velocity) was evaluated 24, 48 and 72 h after hormonal treatments. Males did not release sperm in the control group injected with physiological solution, while sperm could not be collected 7 days after treatments in all hormonally treated groups. Spermiation rates were 100 % in the CPE and Ovopel groups and 25-50 % in the GnRHa-treated groups. Sperm production was significantly lower in the GnRHa-treated groups than in the CPE and Ovopel groups and decreased 72 h after hormonal treatment. Sperm motility and velocity were higher in the Ovopel and GnRHa (75 μg) groups compared to the CPE and GnRHa (25 μg) groups and decreased 72 h after hormonal treatment. Androgens were only affected in spermiating males and changed in the Ovopel and GnRHa (75 μg) after hormonal treatment. Significant correlations were observed between sperm production, sperm motility and sperm velocity, but not androgens. The present study suggests involvement of dopamine in sturgeon spawning. Additionally, better sperm quality observed in the Ovopel group and particularly sperm motility in the GnRHa (75 μg) suggests enhancement of sperm quality in sturgeon treated with GnRHa. Therefore, further study is needed to induce fully spermiation using GnRHa implants in combination with a dopamine inhibitor. © 2012 Springer Science+Business Media B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2011

Pavlidis, Michail A; Chatzifotis, Stavros; Adachi, Kohsuke

Pigmentation Physiology and Discoloration Problems Incollection

Pavlidis, Michail A; Mylonas, Constantinos C (Ed.): Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species, pp. 295–319, Wiley-Blackwell, Oxford, UK, 2011, ISBN: 978-1-4443-9221-0 978-1-4051-9772-4.

Links | BibTeX

Hanel, Reinhold; Tsigenopoulos, Costas S

Phylogeny, Evolution and Taxonomy of Sparids with Some Notes on their Ecology and Biology Incollection

Pavlidis, Michail A; Mylonas, Constantinos C (Ed.): Sparidae, pp. 51–73, Wiley-Blackwell, Oxford, UK, 2011, ISBN: 978-1-4443-9221-0 978-1-4051-9772-4.

Links | BibTeX

Teles, Aires Oliva; Lupatsch, Ingrid; Nengas, Ioannis

Nutrition and Feeding of Sparidae Incollection

Pavlidis, Michail A; Mylonas, Constantinos C (Ed.): Sparidae, pp. 199–232, Wiley-Blackwell, Oxford, UK, 2011, ISBN: 978-1-4443-9221-0 978-1-4051-9772-4.

Links | BibTeX

Blázquez, M; González, A; Mylonas, C C; Piferrer, F

Cloning and sequence analysis of a vasa homolog in the European sea bass (Dicentrarchus labrax): Tissue distribution and mRNA expression levels during early development and sex differentiation Journal Article

General and Comparative Endocrinology, 170 (2), pp. 322–333, 2011, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{blazquez_cloning_2011,
title = {Cloning and sequence analysis of a vasa homolog in the European sea bass (Dicentrarchus labrax): Tissue distribution and mRNA expression levels during early development and sex differentiation},
author = {M Blázquez and A González and C C Mylonas and F Piferrer},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650676645&doi=10.1016%2fj.ygcen.2010.10.007&partnerID=40&md5=db1abcc0ba3345cedb2b6f511324c639},
doi = {10.1016/j.ygcen.2010.10.007},
issn = {00166480},
year = {2011},
date = {2011-01-01},
journal = {General and Comparative Endocrinology},
volume = {170},
number = {2},
pages = {322--333},
abstract = {Vasa is a protein expressed mainly in germ cells and conserved across taxa. However, sex-related differences and environmental influences on vasa expression have not been documented. This study characterized the cDNA of a vasa homolog in the European sea bass, Dicentrarchus labrax (sb-vasa), a gonochoristic fish with temperature influences on gonadogenesis. The 1911 bp open reading frame predicted a 637-amino acid protein with the eight conserved domains typical of Vasa proteins. Comparisons of the deduced amino acid sequence with those of other vertebrates and invertebrates revealed the highest homology (68-85%) with those of other teleosts. An updated tree with the full-length sequences for Vasa proteins in 66 species belonging to six different phyla was constructed, establishing the evolutionary relationships of Vasa amino acid sequences. European sea bass vasa was highly expressed in gonads with little or no expression in other tissues. Real time RT-PCR quantification of the temporal expression of sb-vasa from early development throughout sex differentiation showed that mRNA levels were high in unfertilized eggs, decreased during larval development and increased again during the period of germ cell proliferation. Rearing of fish at high temperature resulted in further increased sb-vasa levels, most likely reflecting temperature effects on both somatic and gonadal growth. Differences in expression were also found well before sex differentiation and persisted until the end of the first year, with higher levels present in females. These differences in expression demonstrate the implication of vasa during the initial stages of fish sex differentiation and gametogenesis and suggest that, through its helicase activity, it might be implicated in the translational regulation of mRNAs involved in the specification and differentiation of gonadal-specific cell types. © 2010 Elsevier Inc.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Pavlidis, M A; Mylonas, C C

Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species Book

Wiley-Blackwell, 2011, ISBN: 978-1-4051-9772-4, (Publication Title: Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species).

Abstract | Links | BibTeX

@book{pavlidis_sparidae_2011,
title = {Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species},
author = {M A Pavlidis and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863878331&doi=10.1002%2f9781444392210&partnerID=40&md5=ed6df67eb4385620df219b4f26241853},
doi = {10.1002/9781444392210},
isbn = {978-1-4051-9772-4},
year = {2011},
date = {2011-01-01},
publisher = {Wiley-Blackwell},
abstract = {The Sparidae, commonly known as breams and porgies, is a family of fishes of the order Perciformes, and includes about 115 species of mainly marine coastal fish of high economic value, exploited and farmed for human consumption, as well as for recreational purposes. This landmark publication brings together a huge wealth of information on the biology and culture of gilthead sea bream and other Sparidae species. Commencing with an overview of the current status of aquaculture of Sparidae, the book continues with comprehensive coverage of the family's phylogeny, evolution and taxonomy, stress and welfare issues, and reproduction and broodstock management. Further chapters include coverage of early development and metabolism, production systems, nutrition, quality, and health management. A final cutting-edge chapter looks at genomic-proteomic research in Sparidae and its application to genetic improvement. With contributions from Europe, the Middle East, Asia, Australasia and North America, carefully drawn together and edited by Professor M. Pavlidis and Dr C. C. Mylonas, themselves well known for their work in this area, Sparidae is an essential purchase for anyone working with this important family of fishes. Fish biologists, fish farmers, aquaculture researchers, and fisheries managers will all find much of great use and interest within this book's covers. All universities and research establishments where biological sciences, aquaculture and fisheries science are studied and taught should have copies of this excellent book on their shelves.. © 2011 Blackwell Publishing Ltd.},
note = {Publication Title: Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species},
keywords = {},
pubstate = {published},
tppubtype = {book}
}

Aranda, G; Aragón, L; Corriero, A; Mylonas, C C; la Gándara, F D; Belmonte, A; Medina, A

GnRHa-induced spawning in cage-reared Atlantic bluefin tuna: An evaluation using stereological quantification of ovarian post-ovulatory follicles Journal Article

Aquaculture, 317 (1-4), pp. 255–259, 2011, ISSN: 00448486.

Abstract | Links | BibTeX

@article{aranda_gnrha-induced_2011,
title = {GnRHa-induced spawning in cage-reared Atlantic bluefin tuna: An evaluation using stereological quantification of ovarian post-ovulatory follicles},
author = {G Aranda and L Aragón and A Corriero and C C Mylonas and F D la Gándara and A Belmonte and A Medina},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79956059456&doi=10.1016%2fj.aquaculture.2011.04.030&partnerID=40&md5=85ab5b93a10a6188d45f976da5bf4168},
doi = {10.1016/j.aquaculture.2011.04.030},
issn = {00448486},
year = {2011},
date = {2011-01-01},
journal = {Aquaculture},
volume = {317},
number = {1-4},
pages = {255--259},
abstract = {The effect of a delivery system (implant) loaded with gonadotropin-releasing hormone agonist (GnRHa) on the spawning performance in captive-reared Atlantic bluefin tuna (Thunnus thynnus) was assessed by means of stereological quantification of ovarian post-ovulatory follicles (POF). Among untreated control fish no follicles were observed at the oocyte maturation (OM) stage; in contrast, 10 of the 16 GnRHa-treated fish showed follicles containing migratory-nucleus oocytes and/or hydrating oocytes. Post-ovulatory follicles were observed only in three of the 14 untreated individuals examined, while all but one GnRHa-induced fish showed POF in the ovary. Nevertheless, when POF were present in the ovary, the amount of ovulated oocytes was not found to be significantly different among GnRHa-treated and untreated control fish, and wild spawners. The relative batch fecundity (eggs g-1 of body mass) estimated from ovarian POF counts were 109.62±28.36 (control group), 68.92±13.05 (GnRHa-treated group) and 83.47±15.63 (wild group). It was concluded that treatment with GnRHa implant stimulated OM and spawning in captivity, thus enhancing the reproductive potential of the broodstocks; however, there appears to be a limitation in the number of eggs maturing in each batch, and the spawn fecundity was not increased by the hormonal treatment. © 2011 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Molés, G; Gómez, A; Carrillo, M; Rocha, A; Mylonas, C C; Zanuy, S

Determination of FSH quantity and bioactivity during sex differentiation and oogenesis in European sea bass Journal Article

Biology of Reproduction, 85 (4), pp. 848–857, 2011, ISSN: 00063363.

Abstract | Links | BibTeX

Vazirzadeh, A; Amiri, Mojazi B; Yelghi, S; Hajimoradloo, A; Nematollahi, M A; Mylonas, C C

Comparison of the effects of different methods of mammalian and salmon GnRHa administration on spawning performance in wild-caught female carp (Cyprinus carpio carpio) from the Caspian Sea Journal Article

Aquaculture, 320 (1-2), pp. 123–128, 2011, ISSN: 00448486.

Abstract | Links | BibTeX

@article{vazirzadeh_comparison_2011,
title = {Comparison of the effects of different methods of mammalian and salmon GnRHa administration on spawning performance in wild-caught female carp (Cyprinus carpio carpio) from the Caspian Sea},
author = {A Vazirzadeh and B Mojazi Amiri and S Yelghi and A Hajimoradloo and M A Nematollahi and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052910790&doi=10.1016%2fj.aquaculture.2011.08.001&partnerID=40&md5=6ea01c848227f4951feab777244c5ff5},
doi = {10.1016/j.aquaculture.2011.08.001},
issn = {00448486},
year = {2011},
date = {2011-01-01},
journal = {Aquaculture},
volume = {320},
number = {1-2},
pages = {123--128},
abstract = {The effects of acute or sustained administration of mammalian and salmon GnRH agonists (mGnRHa and sGnRHa) were examined on the reproduction performance of wild-caught female carp from the Caspian Sea. Ripe broodfish were caught in the beginning of spawning season (early May) by seine from the southeast coastal waters of the Caspian Sea, Golestan province, Iran. To induce spawning fish were allocated into 8 groups and treated with 7% physiological saline (control), 4mgkg-1 carp pituitary (CP) extract (positive control), 20μgkg-1 mGnRHa or sGnRHa together with 40mgkg-1 Metoclopramide (acute treatments), a cholesterol pellet containing 20μgkg-1 mGnRHa or sGnRHa together with 40mgkg-1 Metoclopramide, and emulsified GnRHa in Freud's Incomplete Adjuvant (FIA) containing 20μgkg-1 mGnRHa or sGnRHa together with 40mgkg-1 Metoclopramide (mGnRHa-FIA and sGnRHa-FIA). After the final injection the fish were checked for spawning regularly. Ovulated fish were stripped manually and the eggs fertilized artificially. Significant differences were observed in the reproduction success, latency period and practical fecundity among treated groups (p≤0.05). Injection of CP or sGnRHa in acute or sustained methods increased significantly the reproduction success compared to acute injection, implanting of mGnRHa or controls (p≤0.05). In spite of the weaker effect of mGnRHa injection or cholesterol implant on induction of ovulation, treatment with mGnRHa-FIA showed similar effects as sGnRHa-FIA. Almost all sustained delivery systems of both GnRHa enhanced the practical fecundity of treated fish compared to CP and acute GnRHa injections. The latency periods of fish that received GnRHa-FIA and implant were near 24 and 50h, respectively, which were significantly longer than that of fish given an acute GnRHa treatment or CP (p≤0.05). There was no significant difference in fertilization and hatching success of the produced progeny among treated groups (p≥0.05). The results showed that injection of GnRHa in FIA increased significantly the ovulation success of fish, but implanting fish with mGnRHa in a cholesterol pellet had variable effects with increasing fecundity but not higher ovulation success, compared to the CP treatment. © 2011 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The effects of acute or sustained administration of mammalian and salmon GnRH agonists (mGnRHa and sGnRHa) were examined on the reproduction performance of wild-caught female carp from the Caspian Sea. Ripe broodfish were caught in the beginning of spawning season (early May) by seine from the southeast coastal waters of the Caspian Sea, Golestan province, Iran. To induce spawning fish were allocated into 8 groups and treated with 7% physiological saline (control), 4mgkg-1 carp pituitary (CP) extract (positive control), 20μgkg-1 mGnRHa or sGnRHa together with 40mgkg-1 Metoclopramide (acute treatments), a cholesterol pellet containing 20μgkg-1 mGnRHa or sGnRHa together with 40mgkg-1 Metoclopramide, and emulsified GnRHa in Freud's Incomplete Adjuvant (FIA) containing 20μgkg-1 mGnRHa or sGnRHa together with 40mgkg-1 Metoclopramide (mGnRHa-FIA and sGnRHa-FIA). After the final injection the fish were checked for spawning regularly. Ovulated fish were stripped manually and the eggs fertilized artificially. Significant differences were observed in the reproduction success, latency period and practical fecundity among treated groups (p≤0.05). Injection of CP or sGnRHa in acute or sustained methods increased significantly the reproduction success compared to acute injection, implanting of mGnRHa or controls (p≤0.05). In spite of the weaker effect of mGnRHa injection or cholesterol implant on induction of ovulation, treatment with mGnRHa-FIA showed similar effects as sGnRHa-FIA. Almost all sustained delivery systems of both GnRHa enhanced the practical fecundity of treated fish compared to CP and acute GnRHa injections. The latency periods of fish that received GnRHa-FIA and implant were near 24 and 50h, respectively, which were significantly longer than that of fish given an acute GnRHa treatment or CP (p≤0.05). There was no significant difference in fertilization and hatching success of the produced progeny among treated groups (p≥0.05). The results showed that injection of GnRHa in FIA increased significantly the ovulation success of fish, but implanting fish with mGnRHa in a cholesterol pellet had variable effects with increasing fecundity but not higher ovulation success, compared to the CP treatment. © 2011 Elsevier B.V.

Corriero, A; Zupa, R; Bello, G; Mylonas, C C; Deflorio, M; Genovese, S; Basilone, G; Buscaino, G; Buffa, G; Pousis, C; Metrio, De G; Santamaria, N

Evidence that severe acute stress and starvation induce rapid atresia of ovarian vitellogenic follicles in Atlantic bluefin tuna, Thunnus thynnus (L.) (Osteichthyes: Scombridae) Journal Article

Journal of Fish Diseases, 34 (11), pp. 853–860, 2011, ISSN: 01407775.

Abstract | Links | BibTeX

Pousis, C; Giorgi, De C; Mylonas, C C; Bridges, C R; Zupa, R; Vassallo-Agius, R; de la Gándara, F; Dileo, C; Metrio, De G; Corriero, A

Comparative study of liver vitellogenin gene expression and oocyte yolk accumulation in wild and captive Atlantic bluefin tuna (Thunnus thynnus L.) Journal Article

Animal Reproduction Science, 123 (1-2), pp. 98–105, 2011, ISSN: 03784320.

Abstract | Links | BibTeX

@article{pousis_comparative_2011,
title = {Comparative study of liver vitellogenin gene expression and oocyte yolk accumulation in wild and captive Atlantic bluefin tuna (Thunnus thynnus L.)},
author = {C Pousis and C De Giorgi and C C Mylonas and C R Bridges and R Zupa and R Vassallo-Agius and F de la Gándara and C Dileo and G De Metrio and A Corriero},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78751702603&doi=10.1016%2fj.anireprosci.2010.10.005&partnerID=40&md5=cc8dfb13b9f1ff54e146ab3611526125},
doi = {10.1016/j.anireprosci.2010.10.005},
issn = {03784320},
year = {2011},
date = {2011-01-01},
journal = {Animal Reproduction Science},
volume = {123},
number = {1-2},
pages = {98--105},
abstract = {The sequence of vitellogenin A (VgA) and vitellogenin B (VgB) cDNAs in Atlantic bluefin tuna (Thunnus thynnus L.) were determined, and vitellogenin expression levels in the liver and oocyte yolk accumulation were compared in wild and captive-reared individuals. Liver and ovary samples were taken from 31 individuals reared experimentally in three commercial Atlantic bluefin tuna fattening sites in the Mediterranean Sea and from 33 wild individuals caught by commercial traps during the fish's migration towards their Mediterranean spawning grounds. The total length of VgA cDNA was 5585 nucleotides and that of VgB was 5267 nucleotides. The identity and similarity between deduced amino acid sequences of VgA and VgB were 60% and 78%, respectively. The Atlantic bluefin tuna VgA and VgB amino acid sequences have high similarities with those of other teleost fishes. Relative levels of VgA and VgB mRNAs were low in April, increased significantly during the reproductive period in May and June, and declined in July. There was a trend towards higher relative levels of VgA and VgB mRNAs in captive fish compared to wild individuals during the reproductive period. The surface occupied by eosinophilic yolk granules in fully vitellogenic oocytes, as well as the frequency of oocytes in late vitellogenesis, was significantly higher in captive compared to wild individuals. The study suggests that the experimental conditions under which Atlantic bluefin tuna individuals were reared allowed the occurrence of normal vitellogenesis, based on gene expression of VgA and VgB in the liver and yolk accumulation in the oocytes. The higher yolk accumulation and frequency of vitellogenic oocytes observed in the ovaries of captive fish suggest that improvements in feeding practices may result in an improved vitellogenic process. © 2010 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Fanouraki, E; Mylonas, C C; Papandroulakis, N; Pavlidis, M

Species specificity in the magnitude and duration of the acute stress response in Mediterranean marine fish in culture Journal Article

General and Comparative Endocrinology, 173 (2), pp. 313–322, 2011, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{fanouraki_species_2011,
title = {Species specificity in the magnitude and duration of the acute stress response in Mediterranean marine fish in culture},
author = {E Fanouraki and C C Mylonas and N Papandroulakis and M Pavlidis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79961127644&doi=10.1016%2fj.ygcen.2011.06.004&partnerID=40&md5=193a6e0e97c4f57c5cf13a1562900142},
doi = {10.1016/j.ygcen.2011.06.004},
issn = {00166480},
year = {2011},
date = {2011-01-01},
journal = {General and Comparative Endocrinology},
volume = {173},
number = {2},
pages = {313--322},
abstract = {The aim of the present study was to examine the species-specific stress response for seven Mediterranean fishes in culture. Also, to evaluate the method of measuring free cortisol concentration in the rearing water as a non-invasive and reliable indicator of stress in marine species, of aquaculture importance. Gilthead sea bream, Sparus aurata (Sparidae); common dentex, Dentex dentex (Sparidae); common Pandora, Pagellus erythrinus (Sparidae); sharpsnout sea bream, Diplodus puntazzo (Sparidae); dusky grouper, Epinephelus marginatus (Serranidae); meagre, Argyrosomus regius (Sciaenidae) and European sea bass, Dicentrarchus labrax (Moronidae) were subjected to identical acute stress (5-6 min chasing and 1-1.5. min air exposure) under the same environmental conditions and samples were analyzed by the same procedures. Results indicated that there was a clear species-specificity in the magnitude, timing and duration of the stress response in terms of cortisol, glucose and lactate. European sea bass showed a very high response and dusky grouper and meagre a very low response, except plasma glucose concentrations of dusky grouper which was constantly high, while sharpsnout sea bream presented a protracted stress response, up to 8 h. The present study confirmed that free cortisol release rate into the water can be used as a reliable stress indicator. © 2011 Elsevier Inc.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Guzmán, J M; Cal, R; García-López, A; Chereguini, O; Kight, K; Olmedo, M; Sarasquete, C; Mylonas, C C; Peleteiro, J B; Zohar, Y; Mañanós, E L

Effects of in vivo treatment with the dopamine antagonist pimozide and gonadotropin-releasing hormone agonist (GnRHa) on the reproductive axis of Senegalese sole (Solea senegalensis) Journal Article

Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology, 158 (2), pp. 235–245, 2011, ISSN: 10956433.

Abstract | Links | BibTeX

@article{guzman_effects_2011,
title = {Effects of in vivo treatment with the dopamine antagonist pimozide and gonadotropin-releasing hormone agonist (GnRHa) on the reproductive axis of Senegalese sole (Solea senegalensis)},
author = {J M Guzmán and R Cal and A García-López and O Chereguini and K Kight and M Olmedo and C Sarasquete and C C Mylonas and J B Peleteiro and Y Zohar and E L Mañanós},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650520619&doi=10.1016%2fj.cbpa.2010.11.016&partnerID=40&md5=37e989b8a3d3ee53abad253f9237b964},
doi = {10.1016/j.cbpa.2010.11.016},
issn = {10956433},
year = {2011},
date = {2011-01-01},
journal = {Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology},
volume = {158},
number = {2},
pages = {235--245},
abstract = {The Senegalese sole (Solea senegalensis) is a flatfish that exhibits severe reproductive dysfunctions in captivity. This study aimed at investigating the existence of a dopamine (DA) inhibitory tone on the reproductive axis of this species. Four groups of Senegalese sole breeders were treated with, saline (controls, CNT), the DA antagonist pimozide (PIM, 5mg kg-1), gonadotropin-releasing hormone agonist (GnRHa, 40μg kg-1) or a combination of PIM + GnRHa (COMB). Effects were evaluated on pituitary GnRH levels (ELISA), pituitary gonadotropin subunit transcript levels (qPCR), plasma levels of sex steroids and vitellogenin (ELISA), gonad development (histology), spermiation and egg production. The GnRHa treatment induced egg release and stimulated testis maturation. In males, PIM did not affect pituitary GnRH content, but enhanced GnRHa-induced pituitary GPα transcripts and modified plasma androgen levels; moreover, PIM stimulated spermatogenesis and milt production, both alone and combined with GnRHa. In females, PIM did not affect pituitary and plasma endocrine parameters and did not affect egg production and fertilization success of the broodstock, either alone or in the combined treatment. In conclusion, data indicated the existence of a DA inhibition in mature males, which would be absent or weakly expressed in females. © 2010 Elsevier Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Zohar, Y; Pankhurst, N; Kagawa, H

Reproduction and Broodstock Management Incollection

Pavlidis, M A; Mylonas, C C (Ed.): Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species, Wiley-Blackwell, 2011, ISBN: 978-1-4051-9772-4, (Publication Title: Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species).

Abstract | Links | BibTeX

Guzmán, J M; Ramos, J; Mylonas, C C; Mañanós, E L

Comparative effects of human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone agonist (GnRHa) treatments on the stimulation of male Senegalese sole (Solea senegalensis) reproduction Journal Article

Aquaculture, 316 (1-4), pp. 121–128, 2011, ISSN: 00448486.

Abstract | Links | BibTeX

@article{guzman_comparative_2011,
title = {Comparative effects of human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone agonist (GnRHa) treatments on the stimulation of male Senegalese sole (Solea senegalensis) reproduction},
author = {J M Guzmán and J Ramos and C C Mylonas and E L Mañanós},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955166502&doi=10.1016%2fj.aquaculture.2011.03.014&partnerID=40&md5=4018c202a4338a03dc4f1de68462b638},
doi = {10.1016/j.aquaculture.2011.03.014},
issn = {00448486},
year = {2011},
date = {2011-01-01},
journal = {Aquaculture},
volume = {316},
number = {1-4},
pages = {121--128},
abstract = {The aquaculture of Senegalese sole (Solea senegalensis) is limited by the failure of cultured breeders (F1 generation) to produce fertilized spawning. Critical reproductive dysfunctions have been observed in both female and male Senegalese sole cultured breeders, including reduced fecundity and diminished sperm production. The present work aimed to study the effectiveness of different hormonal treatments on the stimulation of male reproduction. Male Senegalese sole cultured breeders were treated with 1) saline injections (controls), 2) gonadotropin-releasing hormone agonist (GnRHa) injections (25μgkg-1), 3) GnRHa slow release implants (40μgkg-1) or 4) human chorionic gonadotropin (hCG) injections (1000IUkg-1). Each group of males was placed in separated spawning tanks together with females treated with GnRHa implants.All three hormonal treatments increased plasma testosterone (T) and 11-ketotestosterone (11-KT) levels and the gonadosomatic index (GSI), with highest effects exerted by the hCG treatment. Histological examination of the testes showed no effect of the GnRHa injection, but a clear stimulation of germ cell proliferation and testicular maturation by GnRHa implants and hCG injections. As expected, GnRHa implantation of females induced egg release in all experimental tanks and interestingly, female fecundity increased in tanks containing GnRHa- or hCG-treated males. A fertilized spawning was obtained only from the group containing hCG-treated males. In conclusion, hormonal treatments stimulated steroidogenesis and spermatogenesis in male Senegalese sole, with highest efficiency of the hCG multiple injection treatment. Female fecundity was affected by the hormonal treatment applied over the accompanying males, suggesting a pheromone communication between fish. However, none of the treatments seemed to be adequate in solving the problem of lack of fertilized spawning in cultured Senegalese sole broodstocks. © 2011 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Pavlidis, Μ; Chatzifotis, S; Adachi, K

Pigmentation Physiology and Discoloration Problems. In Sea Bream: Biology & Aquaculture of Sparidae. Incollection

Pavlidis, M; Mylonas, C (Ed.): Sea Bream: Biology & Aquaculture of Sparidae., pp. 295–319, Wiley-Blackwell, 2011, ISBN: 978-1-4443-9221-0, (Backup Publisher: Wiley-Blackwell Section: Pigmentation Physiology and Discoloration Problems.).

Links | BibTeX

2010

Chatzifotis, S; Panagiotidou, M; Papaioannou, N; Pavlidis, M; Nengas, I; Mylonas, C C

Effect of dietary lipid levels on growth, feed utilization, body composition and serum metabolites of meagre (Argyrosomus regius) juveniles Journal Article

Aquaculture, 307 (1-2), pp. 65–70, 2010, ISSN: 00448486.

Abstract | Links | BibTeX

@article{chatzifotis_effect_2010,
title = {Effect of dietary lipid levels on growth, feed utilization, body composition and serum metabolites of meagre (Argyrosomus regius) juveniles},
author = {S Chatzifotis and M Panagiotidou and N Papaioannou and M Pavlidis and I Nengas and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955846974&doi=10.1016%2fj.aquaculture.2010.07.002&partnerID=40&md5=829d87c0b4207df0267d190b224ca203},
doi = {10.1016/j.aquaculture.2010.07.002},
issn = {00448486},
year = {2010},
date = {2010-01-01},
journal = {Aquaculture},
volume = {307},
number = {1-2},
pages = {65--70},
abstract = {The study investigates the effect of dietary lipids on growth of meagre (Argyrosomus regius) juveniles. Triplicate groups of fish (average weight ± SD, 229.7 ± 1.4. g) were fed for 110. days three isonitrogenous experimental diets (43% crude protein, dry matter) containing 13, 17, or 21% crude lipids. Body weight, total length and specific growth rate of fish fed the 17% lipid diet were significantly higher than that of fish fed the 13 and 21% lipid diets. Daily feed intake was not affected by the dietary lipid level, but there were significant differences in feed conversion ratio and protein efficiency ratio. There was no significant difference in condition factor, hepatosomatic or viscerosomatic indexes. Proximate analysis indicated that the lipid content of whole body and muscle was affected by the diets, whereas the other chemical components of whole body, muscle and liver were unaffected by the increase in dietary lipid content. Whole body and muscle of fish fed the 21% lipid diet showed significantly higher values of total lipids (whole body: 7.41 ± 0.45% and muscle: 0.64 ± 0.13%) than fish fed 17 and 13% lipid (whole body: 5.92 ± 0.12%, muscle: 0.37 ± 0.08% and whole body: 5.76 ± 0.23%, muscle: 0.31 ± 0.02%, respectively). Serum metabolites did not show significant differences among the three dietary lipid levels. Overall, the results indicated that the best growth performance was observed in fish fed the 17% lipid diet, whereas the increase of dietary lipid level from 17% to 21% had a negative effect on growth. In conclusion, meagre juveniles appear to have similar lipid requirements with other Mediterranean species and excess dietary lipid level should be avoided, since the increase from 17% to 21% resulted in higher fat accretion and impaired growth performance. © 2010 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Fostier, A; Zanuy, S

Broodstock management and hormonal manipulations of fish reproduction Journal Article

General and Comparative Endocrinology, 165 (3), pp. 516–534, 2010, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{mylonas_broodstock_2010,
title = {Broodstock management and hormonal manipulations of fish reproduction},
author = {C C Mylonas and A Fostier and S Zanuy},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-73349136756&doi=10.1016%2fj.ygcen.2009.03.007&partnerID=40&md5=a7f52a27c47b6f76d51ce87f65a7d805},
doi = {10.1016/j.ygcen.2009.03.007},
issn = {00166480},
year = {2010},
date = {2010-01-01},
journal = {General and Comparative Endocrinology},
volume = {165},
number = {3},
pages = {516--534},
abstract = {Control of reproductive function in captivity is essential for the sustainability of commercial aquaculture production, and in many fishes it can be achieved by manipulating photoperiod, water temperature or spawning substrate. The fish reproductive cycle is separated in the growth (gametogenesis) and maturation phase (oocyte maturation and spermiation), both controlled by the reproductive hormones of the brain, pituitary and gonad. Although the growth phase of reproductive development is concluded in captivity in most fishes-the major exemption being the freshwater eel (Anguilla spp.), oocyte maturation (OM) and ovulation in females, and spermiation in males may require exogenous hormonal therapies. In some fishes, these hormonal manipulations are used only as a management tool to enhance the efficiency of egg production and facilitate hatchery operations, but in others exogenous hormones are the only way to produce fertilized eggs reliably. Hormonal manipulations of reproductive function in cultured fishes have focused on the use of either exogenous luteinizing hormone (LH) preparations that act directly at the level of the gonad, or synthetic agonists of gonadotropin-releasing hormone (GnRHa) that act at the level of the pituitary to induce release of the endogenous LH stores, which, in turn act at the level of the gonad to induce steroidogenesis and the process of OM and spermiation. After hormonal induction of maturation, broodstock should spawn spontaneously in their rearing enclosures, however, the natural breeding behavior followed by spontaneous spawning may be lost in aquaculture conditions. Therefore, for many species it is also necessary to employ artificial gamete collection and fertilization. Finally, a common question in regards to hormonal therapies is their effect on gamete quality, compared to naturally maturing or spawning broodfish. The main factors that may have significant consequences on gamete quality-mainly on eggs-and should be considered when choosing a spawning induction procedure include (a) the developmental stage of the gonads at the time the hormonal therapy is applied, (b) the type of hormonal therapy, (c) the possible stress induced by the manipulation necessary for the hormone administration and (d) in the case of artificial insemination, the latency period between hormonal stimulation and stripping for in vitro fertilization. © 2009 Elsevier Inc. All rights reserved.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Control of reproductive function in captivity is essential for the sustainability of commercial aquaculture production, and in many fishes it can be achieved by manipulating photoperiod, water temperature or spawning substrate. The fish reproductive cycle is separated in the growth (gametogenesis) and maturation phase (oocyte maturation and spermiation), both controlled by the reproductive hormones of the brain, pituitary and gonad. Although the growth phase of reproductive development is concluded in captivity in most fishes-the major exemption being the freshwater eel (Anguilla spp.), oocyte maturation (OM) and ovulation in females, and spermiation in males may require exogenous hormonal therapies. In some fishes, these hormonal manipulations are used only as a management tool to enhance the efficiency of egg production and facilitate hatchery operations, but in others exogenous hormones are the only way to produce fertilized eggs reliably. Hormonal manipulations of reproductive function in cultured fishes have focused on the use of either exogenous luteinizing hormone (LH) preparations that act directly at the level of the gonad, or synthetic agonists of gonadotropin-releasing hormone (GnRHa) that act at the level of the pituitary to induce release of the endogenous LH stores, which, in turn act at the level of the gonad to induce steroidogenesis and the process of OM and spermiation. After hormonal induction of maturation, broodstock should spawn spontaneously in their rearing enclosures, however, the natural breeding behavior followed by spontaneous spawning may be lost in aquaculture conditions. Therefore, for many species it is also necessary to employ artificial gamete collection and fertilization. Finally, a common question in regards to hormonal therapies is their effect on gamete quality, compared to naturally maturing or spawning broodfish. The main factors that may have significant consequences on gamete quality-mainly on eggs-and should be considered when choosing a spawning induction procedure include (a) the developmental stage of the gonads at the time the hormonal therapy is applied, (b) the type of hormonal therapy, (c) the possible stress induced by the manipulation necessary for the hormone administration and (d) in the case of artificial insemination, the latency period between hormonal stimulation and stripping for in vitro fertilization. © 2009 Elsevier Inc. All rights reserved.

Suquet, M; Cosson, J; Gándara, De La F; Mylonas, C C; Papadaki, M; Lallemant, S; Fauvel, C

Sperm features of captive Atlantic bluefin tuna (Thunnus thynnus) Journal Article

Journal of Applied Ichthyology, 26 (5), pp. 775–778, 2010, ISSN: 01758659.

Abstract | Links | BibTeX

Metrio, De G; Bridges, C R; Mylonas, C C; Caggiano, M; Deflorio, M; Santamaria, N; Zupa, R; Pousis, C; Vassallo-Agius, R; Gordin, H; Corriero, A

Spawning induction and large-scale collection of fertilized eggs in captive Atlantic bluefin tuna (Thunnus thynnus L.) and the first larval rearing efforts Journal Article

Journal of Applied Ichthyology, 26 (4), pp. 596–599, 2010, ISSN: 01758659.

Links | BibTeX

Mylonas, C C; de la Gándara, F; Corriero, A; Ríos, A B

Atlantic bluefin tuna (Thunnus thynnus) farming and fattening in the Mediterranean sea Journal Article

Reviews in Fisheries Science, 18 (3), pp. 266–280, 2010, ISSN: 10641262.

Abstract | Links | BibTeX

2009

Corriero, A; Medina, A; Mylonas, C C; Bridges, C R; Santamaria, N; Deflorio, M; Losurdo, M; Zupa, R; Gordin, H; de la Gandara, F; Rìos, Belmonte A; Pousis, C; Metrio, De G

Proliferation and apoptosis of male germ cells in captive Atlantic bluefin tuna (Thunnus thynnus L.) treated with gonadotropin-releasing hormone agonist (GnRHa) Journal Article

Animal Reproduction Science, 116 (3-4), pp. 346–357, 2009, ISSN: 03784320.

Abstract | Links | BibTeX

@article{corriero_proliferation_2009,
title = {Proliferation and apoptosis of male germ cells in captive Atlantic bluefin tuna (Thunnus thynnus L.) treated with gonadotropin-releasing hormone agonist (GnRHa)},
author = {A Corriero and A Medina and C C Mylonas and C R Bridges and N Santamaria and M Deflorio and M Losurdo and R Zupa and H Gordin and F de la Gandara and A Belmonte Rìos and C Pousis and G De Metrio},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-70350001941&doi=10.1016%2fj.anireprosci.2009.02.013&partnerID=40&md5=9c00cc45925d4a12e23a5bca186e3bf2},
doi = {10.1016/j.anireprosci.2009.02.013},
issn = {03784320},
year = {2009},
date = {2009-01-01},
journal = {Animal Reproduction Science},
volume = {116},
number = {3-4},
pages = {346--357},
abstract = {The effects of administration of gonadotropin-releasing hormone agonist (GnRHa) on proliferation and apoptosis of male germ cells were evaluated on Atlantic bluefin tuna (Thunnus thynnus L.) reared in captivity. Fish (n = 19) were treated with a sustained-release delivery system loaded with GnRHa during the natural spawning season of 2004 and 2005 (June-July). Untreated Control fish (n = 17) and adult wild spawners were used for comparison. Fish were sacrificed 2-8 d after GnRHa implantation and body weight and gonad weight were recorded, and gonads and blood were taken. Germ cell proliferation and apoptosis were evaluated through the immunohistochemical detection of proliferating cell nuclear antigen (PCNA) and the terminal deoxynucleotidyl transferase-mediated d'UTP nick end labelling (TUNEL) method, respectively. Plasma 11 ketotestosterone (11-KT) levels were measured using an ELISA method. Mean gonado-somatic index and seminiferous lobule diameter did not differ between GnRHa-treated and Control fish, and were significantly lower in captive-reared individuals than in wild spawners. Significant increases in 11-KT plasma levels and spermatogonial mitosis, along with a reduction of germ cell apoptosis were demonstrated in GnRHa-treated fish compared to Controls. The results suggest that GnRHa administration was effective in enhancing germ cell proliferation and reducing apoptosis in captive males through the stimulation of luteinizing hormone (LH) release and testicular 11-KT production. © 2009 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C; Zohar, Y

Controlling fish reproduction in aquaculture Incollection

New Technologies in Aquaculture, pp. 109–142, Elsevier Inc., 2009, ISBN: 978-1-84569-384-8, (Publication Title: New Technologies in Aquaculture: Improving Production Efficiency, Quality and Environmental Management).

Abstract | Links | BibTeX

@incollection{mylonas_controlling_2009,
title = {Controlling fish reproduction in aquaculture},
author = {C Mylonas and Y Zohar},
url = {https://doi.org/10.1533/9781845696474.1.109},
doi = {10.1533/9781845696474.1.109},
isbn = {978-1-84569-384-8},
year = {2009},
date = {2009-01-01},
booktitle = {New Technologies in Aquaculture},
pages = {109--142},
publisher = {Elsevier Inc.},
series = {Woodhead Publishing Series in Food Science, Technology and Nutrition},
abstract = {Industrial aquaculture is a new activity to most parts of the world and is looking for ways to establish a reliable and controlled system for the provision of seed stock for grow-out operations. Control of reproductive function can be achieved, in many fish species, by manipulating photoperiod, water temperature and spawning substrate. The reproductive cycle is separated in two phases - i.e., growth and maturation - which may be controlled by different reproductive hormones at the level of the pituitary and gonad. Although the first phase of reproductive development is concluded in captivity, the second stage of the reproductive cycle - i.e., oocyte maturation (OM) and ovulation in females, and spermiation in males - may require the employment of exogenous hormonal therapies. In some species, these hormonal manipulations are used only as a management tool to enhance the efficiency of egg production and facilitate hatchery operations, but in other fishes exogenous hormones are the only way to produce fertilized eggs at an industrial level. The reproductive cycle is controlled by the interactions of the hormones of the brain-pituitary-gonad axis. From the brain, gonadotropin releasing hormones (GnRHs) travel along neural axons and stimulate the gonadotroph cells of the pituitary to produce and secrete the two gonadotropins (GtH) follicle stimulating hormone (FSH) and luteinizing hormone (LH), which, in turn, act at the level of the gonad to induce steroidogenesis and the production of the androgens, estrogens and progestagens, which are the final effectors of reproductive function. Hormonal manipulations of reproductive function in cultured fishes have focused on the use of either exogenous LH preparations that act directly at the level of the gonad, or synthetic GnRH agonists (GnRHa) that act at the level of the pituitary to induce release of the endogenous LH stores, which, in turn act at the level of the gonad to induce steroidogenesis and the process of OM and spermiation. © 2009 Woodhead Publishing Limited. All rights reserved.},
note = {Publication Title: New Technologies in Aquaculture: Improving Production Efficiency, Quality and Environmental Management},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}

Industrial aquaculture is a new activity to most parts of the world and is looking for ways to establish a reliable and controlled system for the provision of seed stock for grow-out operations. Control of reproductive function can be achieved, in many fish species, by manipulating photoperiod, water temperature and spawning substrate. The reproductive cycle is separated in two phases - i.e., growth and maturation - which may be controlled by different reproductive hormones at the level of the pituitary and gonad. Although the first phase of reproductive development is concluded in captivity, the second stage of the reproductive cycle - i.e., oocyte maturation (OM) and ovulation in females, and spermiation in males - may require the employment of exogenous hormonal therapies. In some species, these hormonal manipulations are used only as a management tool to enhance the efficiency of egg production and facilitate hatchery operations, but in other fishes exogenous hormones are the only way to produce fertilized eggs at an industrial level. The reproductive cycle is controlled by the interactions of the hormones of the brain-pituitary-gonad axis. From the brain, gonadotropin releasing hormones (GnRHs) travel along neural axons and stimulate the gonadotroph cells of the pituitary to produce and secrete the two gonadotropins (GtH) follicle stimulating hormone (FSH) and luteinizing hormone (LH), which, in turn, act at the level of the gonad to induce steroidogenesis and the production of the androgens, estrogens and progestagens, which are the final effectors of reproductive function. Hormonal manipulations of reproductive function in cultured fishes have focused on the use of either exogenous LH preparations that act directly at the level of the gonad, or synthetic GnRH agonists (GnRHa) that act at the level of the pituitary to induce release of the endogenous LH stores, which, in turn act at the level of the gonad to induce steroidogenesis and the process of OM and spermiation. © 2009 Woodhead Publishing Limited. All rights reserved.

Papadakis, I E; Zaiss, M M; Kyriakou, Y; Georgiou, G; Divanach, P; Mylonas, C C

Histological evaluation of the elimination of Artemia nauplii from larval rearing protocols on the digestive system ontogeny of shi drum (Umbrina cirrosa L.) Journal Article

Aquaculture, 286 (1-2), pp. 45–52, 2009, ISSN: 00448486.

Abstract | Links | BibTeX

@article{papadakis_histological_2009,
title = {Histological evaluation of the elimination of Artemia nauplii from larval rearing protocols on the digestive system ontogeny of shi drum (Umbrina cirrosa L.)},
author = {I E Papadakis and M M Zaiss and Y Kyriakou and G Georgiou and P Divanach and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-56649095808&doi=10.1016%2fj.aquaculture.2008.08.028&partnerID=40&md5=98c4d0d5f556cfa435dead4371ff509a},
doi = {10.1016/j.aquaculture.2008.08.028},
issn = {00448486},
year = {2009},
date = {2009-01-01},
journal = {Aquaculture},
volume = {286},
number = {1-2},
pages = {45--52},
abstract = {The influence of the absence of Artemia nauplii from larval diet protocols on growth and digestive system ontogeny was studied using histological techniques in the shi drum (Umbrina cirrosa). One group of larvae was reared using the standard intensive rearing protocol, which offers a combination of enriched rotifers (Brachionus plicatilis), Artemia spp. nauplii and artificial diet (Std-group). Another group was reared using the same protocol, but without the offering of Artemia nauplii (group No-Artemia). The ontogenesis of the digestive system from hatching to metamorphosis was a very rapid process, and there were no differences between the two feeding regimes in the temporal appearance of the various components of the digestive system. The first organised presence of the hepatic and pancreatic tissue appeared at 2-3 d after hatching (dah), suggesting that these organs function from a very early developmental stage. In the No-Artemia larvae between 13 and 29 dah there was a reduction in the height of enterocytes in the intestinal mucosa, a progressive flattening of the primary intestinal folds in the anterior and posterior intestine and a decrease in lipid stores in the liver, suggesting a period of relative starvation. However, by the end of the study at 41 dah, there were no significant differences in body length, intestinal morphology or liver lipid stores between larvae reared under the two feeding regimes. The study suggests that the diet may influence the maturation and/or function, but not the ontogeny of the digestive system. Furthermore, the rapid differentiation of the digestive system in shi drum and the prompt recovery of the No-Artemia larvae from the symptoms of starvation by 29 dah, indicate a plasticity during ontogenesis and the ability of larvae to adapt to artificial diets at very early developmental stages. © 2008 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Pavlidis, M; Papandroulakis, N; Zaiss, M M; Tsafarakis, D; Papadakis, I E; Varsamos, S

Growth performance and osmoregulation in the shi drum (Umbrina cirrosa) adapted to different environmental salinities Journal Article

Aquaculture, 287 (1-2), pp. 203–210, 2009, ISSN: 00448486.

Abstract | Links | BibTeX

@article{mylonas_growth_2009,
title = {Growth performance and osmoregulation in the shi drum (Umbrina cirrosa) adapted to different environmental salinities},
author = {C C Mylonas and M Pavlidis and N Papandroulakis and M M Zaiss and D Tsafarakis and I E Papadakis and S Varsamos},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-58049194052&doi=10.1016%2fj.aquaculture.2008.10.024&partnerID=40&md5=a637928fdea05d4d7f37eda6ccf92d9c},
doi = {10.1016/j.aquaculture.2008.10.024},
issn = {00448486},
year = {2009},
date = {2009-01-01},
journal = {Aquaculture},
volume = {287},
number = {1-2},
pages = {203--210},
abstract = {In order to investigate the ability of shi drum (Umbrina cirrosa) to be reared at diverse locations, growth and osmoregulatory performance were assessed at full-strength seawater (40 psu), nearly iso-osmotic water (10 psu) and low salinity water (4 psu). At the end of the 84-day experimental period, fish reared at 4 psu displayed shorter mean fork length, lower mean body weight, lower specific growth rate and higher food conversion efficiency than fish reared at 10 or 40 psu. The effect of salinity on growth performance was also reflected by changes in plasma triglycerides and cholesterol, with fish reared at 4 psu exhibiting the lowest mean concentrations, while there was no significant difference in mean plasma glucose concentrations among treatments. Plasma osmolality was lower at 4 psu from day 42 onwards, while there was no significant difference in mean plasma K+ and Cl- concentrations. Plasma sodium and gill Na+/K+-ATPase activity showed minimum values on day 42 at 4 psu, but at the end of the experiment there was no difference among groups. Pavement cells, mucus cells and chloride cells were identified by histology on the gill epithelium. In shi drum reared at full seawater, mucus cells contained a mixture of acid and neutral mucins, whereas in fish adapted to hypo-osmotic environment neutral mucins were mainly observed. There was a significant increase in chloride cell number over the course of the study in all fish, but there was no difference among the three experimental salinities. Finally, in fish reared at 40 psu salinity, chloride cells increased in size significantly compared to fish adapted to 4 psu, whereas at 10 psu after 42 d there was a significant reduction in chloride cell size. These results indicate that shi drum reared from full-strength seawater to iso-osmotic salinity do not face any osmoregulatory imbalance, while fish reared in hypo-osmotic water displayed osmoregulatory impairment and low growth performance. © 2008 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

In order to investigate the ability of shi drum (Umbrina cirrosa) to be reared at diverse locations, growth and osmoregulatory performance were assessed at full-strength seawater (40 psu), nearly iso-osmotic water (10 psu) and low salinity water (4 psu). At the end of the 84-day experimental period, fish reared at 4 psu displayed shorter mean fork length, lower mean body weight, lower specific growth rate and higher food conversion efficiency than fish reared at 10 or 40 psu. The effect of salinity on growth performance was also reflected by changes in plasma triglycerides and cholesterol, with fish reared at 4 psu exhibiting the lowest mean concentrations, while there was no significant difference in mean plasma glucose concentrations among treatments. Plasma osmolality was lower at 4 psu from day 42 onwards, while there was no significant difference in mean plasma K+ and Cl- concentrations. Plasma sodium and gill Na+/K+-ATPase activity showed minimum values on day 42 at 4 psu, but at the end of the experiment there was no difference among groups. Pavement cells, mucus cells and chloride cells were identified by histology on the gill epithelium. In shi drum reared at full seawater, mucus cells contained a mixture of acid and neutral mucins, whereas in fish adapted to hypo-osmotic environment neutral mucins were mainly observed. There was a significant increase in chloride cell number over the course of the study in all fish, but there was no difference among the three experimental salinities. Finally, in fish reared at 40 psu salinity, chloride cells increased in size significantly compared to fish adapted to 4 psu, whereas at 10 psu after 42 d there was a significant reduction in chloride cell size. These results indicate that shi drum reared from full-strength seawater to iso-osmotic salinity do not face any osmoregulatory imbalance, while fish reared in hypo-osmotic water displayed osmoregulatory impairment and low growth performance. © 2008 Elsevier B.V. All rights reserved.

Guzmán, J M; Ramos, J; Mylonas, C C; Mañanós, E L

Spawning performance and plasma levels of GnRHa and sex steroids in cultured female Senegalese sole (Solea senegalensis) treated with different GnRHa-delivery systems Journal Article

Aquaculture, 291 (3-4), pp. 200–209, 2009, ISSN: 00448486.

Abstract | Links | BibTeX

@article{guzman_spawning_2009,
title = {Spawning performance and plasma levels of GnRHa and sex steroids in cultured female Senegalese sole (Solea senegalensis) treated with different GnRHa-delivery systems},
author = {J M Guzmán and J Ramos and C C Mylonas and E L Mañanós},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349179098&doi=10.1016%2fj.aquaculture.2009.03.024&partnerID=40&md5=f4ceaf77bba0209a875328955c517020},
doi = {10.1016/j.aquaculture.2009.03.024},
issn = {00448486},
year = {2009},
date = {2009-01-01},
journal = {Aquaculture},
volume = {291},
number = {3-4},
pages = {200--209},
abstract = {The aquaculture of Senegalese sole (Solea senegalensis) is limited by the poor spawning performance of the F1 generation cultured broodstock. The present study compared the efficiency of two sustained-release delivery systems loaded with gonadotropin-releasing hormone agonist (GnRHa) and a single GnRHa injection on the stimulation of oocyte maturation (OM), sex steroid hormone secretion and spawning. Analysis with an ELISA showed that the administered GnRHa was no longer detectable in the plasma 3, 7 and 14 d after administration via a single injection, microspheres and an implant, respectively. All GnRHa treatments induced a transient elevation of testosterone (T) and 17β estradiol (E2) plasma levels after 1-3 d. Only three spawns were obtained from controls on days 35, 41 and 42 of the study and ovarian biopsies showed abundant fully vitellogenic oocytes, but little OM. Fish given a GnRHa injection spawned sporadically with the first spawn at 20 days post-treatment (dpt). In contrast, GnRHa implants and microspheres stimulated OM and daily spawning starting at 4 and 5 dpt, respectively, and lasting for a period of 28 d. Total fecundity in the broodstock treated with GnRHa-delivery systems was 15-22 times greater than controls and 3-5 times greater than GnRHa-injected fish. Although egg quality appeared to be high, no fertilization was obtained. The results suggest that GnRHa-delivery systems are highly efficient on stimulating OM and spawning in Senegalese sole, presumably through the long-term elevation of pituitary luteinizing hormone release, which in turn stimulated the appropriate changes in ovarian steroidogenesis. However, the effectiveness of the treatment was negated by possible dysfunctions of the male breeders or of the reproductive behavior of the broodstock. © 2009 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Deloffre, L A M; Martins, R S T; Mylonas, C C; Canario, A V M

Alternative transcripts of DMRT1 in the European sea bass: Expression during gonadal differentiation Journal Article

Aquaculture, 293 (1-2), pp. 89–99, 2009, ISSN: 00448486.

Abstract | Links | BibTeX

@article{deloffre_alternative_2009,
title = {Alternative transcripts of DMRT1 in the European sea bass: Expression during gonadal differentiation},
author = {L A M Deloffre and R S T Martins and C C Mylonas and A V M Canario},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349236364&doi=10.1016%2fj.aquaculture.2009.03.048&partnerID=40&md5=aaf2bf165aa8ec873d79c4bc1b633d22},
doi = {10.1016/j.aquaculture.2009.03.048},
issn = {00448486},
year = {2009},
date = {2009-01-01},
journal = {Aquaculture},
volume = {293},
number = {1-2},
pages = {89--99},
abstract = {DMRT1 is conserved from invertebrates to human and has been implicated in sex differentiation and testis function in many organisms. We report the cloning of two DMRT1 transcripts, DMRT1a and DMRT1b, encoded by a single gene in the European sea bass, Dicentrarchus labrax, a teleost fish with polygenic sex determination influenced by temperature. DMRT1a and DMRT1b are specific to the testis and are present as transcripts of 2.7 and 4.6 kb, as determined by Northern blot, although the cloned cDNAs are 1.2 and 1.9 kb. DMRT1a, encodes a protein of 306-amino acids, of similar size to what has been found in other teleosts, while the DMRT1b encodes a unique protein which differ from DMRT1a by having a 26 amino acids insertion which separates the S and Y domains. This insertion is the result of an extra exon (exon 4), present in the genomes of teleosts but not in other vertebrate genomes. Furthermore, unlike in the European sea bass, the putative product of DMRT1b in other teleost species is a truncated peptide. In European sea bass, the two transcripts are expressed at a similar level and have a similar expression profile in developing gonads. They are first detected by reverse transcription-polymerase chain reaction at 150 days post-hatch coinciding with the start of sex differentiation. After 200 days, expression increases in testis and decreases in ovary. Although it is not clear whether the two transcripts have differential roles it is suggested that both are required for testicular function. © 2009 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2008

Peñaranda, D S; Pérez, L; Fakriadis, G; Mylonas, C C; Asturiano, J F

Effects of extenders and cryoprotectant combinations on motility and morphometry of sea bass (Dicentrarchus labrax) spermatozoa Journal Article

Journal of Applied Ichthyology, 24 (4), pp. 450–455, 2008, ISSN: 01758659.

Abstract | Links | BibTeX

Blázquez, M; González, A; Papadaki, M; Mylonas, C; Piferrer, F

General and Comparative Endocrinology, 158 (1), pp. 95–101, 2008, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{blazquez_sex-related_2008,
title = {Sex-related changes in estrogen receptors and aromatase gene expression and enzymatic activity during early development and sex differentiation in the European sea bass (Dicentrarchus labrax)},
author = {M Blázquez and A González and M Papadaki and C Mylonas and F Piferrer},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-47749115671&doi=10.1016%2fj.ygcen.2008.06.001&partnerID=40&md5=de231a70456b1272ea82f3d813879364},
doi = {10.1016/j.ygcen.2008.06.001},
issn = {00166480},
year = {2008},
date = {2008-01-01},
journal = {General and Comparative Endocrinology},
volume = {158},
number = {1},
pages = {95--101},
abstract = {The present study addresses the role of aromatase and estrogen receptors in sex differentiation and development. With this purpose, a sea bass female- and a male-dominant group were obtained by successive size gradings since in this species females are already larger than males at the time of sex differentiation. Changes in cyp19a and cyp19b gene expression and enzymatic activity were monitored by a validated real-time PCR and a tritiated water assay, respectively, during early development and sex differentiation. Changes in mRNA expression of estrogen receptors, both erb1 and erb2, were also assessed during this period. Results show clear sex-related differences in cyp19a gene expression and enzymatic activity in gonads, with females exhibiting significantly higher levels than males at 150 days post hatching (DPH), when histological signs of sex differentiation were evident. cyp19b gene expression and activity in brain were detectable during early ontogenesis at 50 DPH but no clear sex-related differences were observed. Both erb1 and erb2 showed higher gene expression levels in testis than in ovaries around 200-250 DPH, corresponding with the time of testicular differentiation and precocious male maturation, but no sex-related differences were found in the brain. Together these results indicate that in the European sea bass high expression levels of cyp19a are associated with ovarian differentiation and thus cyp19a can be considered as a suitable molecular marker of ovarian differentiation. However, the involvement of cyp19b in sex differentiation cannot be concluded. In addition, the higher levels of erb1 and erb2 in males versus females during sex differentiation, coinciding with precocious male maturation in the sea bass, suggest an important role for these receptors in testicular development and maturation. © 2008 Elsevier Inc. All rights reserved.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Guzmán, J M; Norberg, B; Ramos, J; Mylonas, C C; Mañanós, E L

Vitellogenin, steroid plasma levels and spawning performance of cultured female Senegalese sole (Solea senegalensis) Journal Article

General and Comparative Endocrinology, 156 (2), pp. 285–297, 2008, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{guzman_vitellogenin_2008,
title = {Vitellogenin, steroid plasma levels and spawning performance of cultured female Senegalese sole (Solea senegalensis)},
author = {J M Guzmán and B Norberg and J Ramos and C C Mylonas and E L Mañanós},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-40849111424&doi=10.1016%2fj.ygcen.2008.02.002&partnerID=40&md5=b63fe9ab1be5a2bfc82b19f3e7554f75},
doi = {10.1016/j.ygcen.2008.02.002},
issn = {00166480},
year = {2008},
date = {2008-01-01},
journal = {General and Comparative Endocrinology},
volume = {156},
number = {2},
pages = {285--297},
abstract = {The Senegalese sole (Solea senegalensis) is a high value market flatfish, which aquaculture is compromised by severe reproductive problems; these are mostly found in soles hatched and raised in captivity (F1 generation). To gain knowledge on the reproductive dysfunctions observed in cultured (F1) Senegalese sole, this work aimed at developing a specific vitellogenin (VTG) ELISA, for the measurement of plasma VTG levels in this species. Profiles of VTG were correlated with those of sexual steroids and spawning performance of an F1 broodstock, during three consecutive years. The Senegalese sole VTG (ssVTG) was purified by precipitation with MgCl2-EDTA and anion-exchange chromatography and showed a molecular mass of 172 kDa, by SDS-PAGE. Specific antibodies were obtained and used to develop a competitive ELISA, which had a sensitivity of 3.6 ng ml-1, and inter- and intra-assay coefficients of variation of 9.5% (n = 29) and 6.7% (n = 12), respectively. Annual profiles of plasma VTG showed a major peak at pre-spawning, and a second minor rise around autumn, which mirrored plasma profiles of both estradiol (E2) and testosterone (T) levels. Spontaneous spawning occurred every year in the spring season, but no fertilized eggs were obtained. In conclusion, this study described, for the first time, the purification and development of a sensitive and specific ELISA for Senegalese sole VTG. The endocrine and spawning data suggested that F1 female broodstock showed normal VTG and steroid releasing profiles in captivity with occurrence of spontaneous spawning, but no fertilization of the eggs was recorded. © 2008 Elsevier Inc. All rights reserved.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Papadaki, M; Papadopoulou, M; Siggelaki, I; Mylonas, C C

Egg and sperm production and quality of sharpsnout sea bream (Diplodus puntazzo) in captivity Journal Article

Aquaculture, 276 (1-4), pp. 187–197, 2008, ISSN: 00448486.

Abstract | Links | BibTeX

@article{papadaki_egg_2008,
title = {Egg and sperm production and quality of sharpsnout sea bream (Diplodus puntazzo) in captivity},
author = {M Papadaki and M Papadopoulou and I Siggelaki and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-41549160104&doi=10.1016%2fj.aquaculture.2008.01.033&partnerID=40&md5=be9ddc2c84556c6f70f1ec0d752baef9},
doi = {10.1016/j.aquaculture.2008.01.033},
issn = {00448486},
year = {2008},
date = {2008-01-01},
journal = {Aquaculture},
volume = {276},
number = {1-4},
pages = {187--197},
abstract = {Egg production from captive-reared sharpsnout sea bream (Diplodus puntazzo) was monitored during the spawning seasons of 2003 to 2005, and sperm production during 2003. Spawning took place between September and December under water temperatures of 21.0-18.5 °C. Daily fecundity varied without a consistent trend and peak egg production occurred in October. Mean (± S.E.M.) number of spawning days per month was 20 ± 3 in 2003, and 14 ± 3 in 2004 and 2005. A significant (ANOVA, DNMR, P < 0.01) drop was observed in mean total annual relative fecundity from 4.9 ± 0.08 million eggs kg- 1 female body weight in 2003, to 2.4 ± 0.07 million eggs kg- 1 in 2004 and 2005. Mean monthly fertilization success also dropped significantly from 81 ± 1% in 2003 to 76 ± 2% in 2004 and 78 ± 2% in 2005. Annual hatching success did not vary significantly and was around 86 ± 2%. Finally, 5 day larval survival decreased significantly from 85 ± 2% in 2003 to 44 ± 3% in 2004. The first spermiating males were found in August and sperm production continued until December. Mean total volume of expressible sperm was maximal in November (3 ± 1 ml kg- 1) and the gonadosomatic index (GSI) ranged between 0.6 and 2.0% in spermiating fish, reaching its peak in September-November. Sperm motility (%) remained unchanged during the season, whereas motility duration (6.2 ± 1.7 min) and sperm density (2.7 ± 0.2 × 1010 spermatozoa ml- 1) peaked in October. Mean sperm survival ranged between 9 and 13 days during most of the spawning season, and decreased significantly to 5 days in December. The study suggests that egg production is stable for the first 3 months of the spawning season, with relatively unchanged egg quality. On the contrary, sperm production and quality peaks in the middle of the reproductive season in October. © 2008 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Heinisch, G; Corriero, A; Medina, A; Abascal, F J; Serna, De La J -M; Vassallo-Agius, R; Ríos, A B; García, A; Gándara, De La F; Fauvel, C; Bridges, C R; Mylonas, C C; Karakulak, S F; Oray, I; Metrio, De G; Rosenfeld, H; Gordin, H

Spatial-temporal pattern of bluefin tuna (Thunnus thynnus L. 1758) gonad maturation across the Mediterranean Sea Journal Article

Marine Biology, 154 (4), pp. 623–630, 2008, ISSN: 00253162.

Abstract | Links | BibTeX

@article{heinisch_spatial-temporal_2008,
title = {Spatial-temporal pattern of bluefin tuna (Thunnus thynnus L. 1758) gonad maturation across the Mediterranean Sea},
author = {G Heinisch and A Corriero and A Medina and F J Abascal and J -M De La Serna and R Vassallo-Agius and A B Ríos and A García and F De La Gándara and C Fauvel and C R Bridges and C C Mylonas and S F Karakulak and I Oray and G De Metrio and H Rosenfeld and H Gordin},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-44449176975&doi=10.1007%2fs00227-008-0955-6&partnerID=40&md5=757ee5d6344302cb3bb4339dbd6f056e},
doi = {10.1007/s00227-008-0955-6},
issn = {00253162},
year = {2008},
date = {2008-01-01},
journal = {Marine Biology},
volume = {154},
number = {4},
pages = {623--630},
abstract = {Atlantic bluefin tuna (BFT; Thunnus thynnus) is a migrating species straddling the North Atlantic Ocean and Mediterranean Sea. It is assumed that this species is divided into a western and an eastern stock, which spawn in the Gulf of Mexico and the Mediterranean Sea, respectively. To learn more about the reproductive behavior of the eastern BFT stock, we tracked gonadal development in adult fish that were sampled between April and July during three consecutive years (2003-2005). Sampling campaigns were carried out using common fishing methods at selected locations within the Mediterranean Sea, namely Levantine Sea, Malta, and Balearic Islands. An additional sampling point, Barbate, was situated northwest of the Straits of Gibraltar along the Atlantic coast. Morphometric parameters such as the total body mass (M B) and the weights of the gonads (M G) were recorded, and the respective gonadosomatic index (GSI) values were calculated. The data collected revealed two important trends: (1) GSI values are higher in fish caught in the eastern rather than the western locations across the Mediterranean Sea, and (2) the GSI reaches maximum values between late May and early June in Levantine Sea (eastern Mediterranean Sea), and only 2 and 4 weeks later in the central (Malta) and western (Balearic Islands) locations, respectively. The advanced gonadal development in BFT correlates well with higher sea surface temperatures. Our findings also distinguish the northern Levantine Sea BFT population (mean M B 78.41 ± 4.13 kg), and the Barbate BFT population with the greatest M B (all fish sampled > 100 kg). These data reflect a situation in which the eastern Mediterranean basin may function as a habitat for young BFT, until they gain a larger M B and are able to move to the Atlantic Ocean. However, the existence of genetically discrete BFT populations in the Mediterranean Sea cannot be ruled out. © 2008 Springer-Verlag.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Micale, V; Giancamillo, Di A; Domeneghini, C; Mylonas, C C; Nomikos, N; Papadakis, I E; Muglia, U

Ontogeny of the digestive tract in sharpsnout sea bream Diplodus puntazzo (Cetti, 1777) Journal Article

Histology and Histopathology, 23 (9), pp. 1077–1091, 2008, ISSN: 02133911.

Abstract | Links | BibTeX

@article{micale_ontogeny_2008,
title = {Ontogeny of the digestive tract in sharpsnout sea bream Diplodus puntazzo (Cetti, 1777)},
author = {V Micale and A Di Giancamillo and C Domeneghini and C C Mylonas and N Nomikos and I E Papadakis and U Muglia},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863988830&partnerID=40&md5=176459c6664c6e794375b702ca2d412e},
issn = {02133911},
year = {2008},
date = {2008-01-01},
journal = {Histology and Histopathology},
volume = {23},
number = {9},
pages = {1077--1091},
abstract = {The ontogeny of the digestive tract was studied histologically and histochemically in sharpsnout sea bream Diplodus puntazzo from hatching (0 DAH, Days After Hatching) until day 57 (57 DAH). At hatching, the digestive tract appeared as a histologically undifferentiated straight tube lying dorsally to the yolk sac. When the mouth opened at 3 DAH, the digestive tract was differentiated into buccopharynx, oesophagus, incipient stomach and intestine. The pancreas, liver and gall bladder were also differentiated at this stage and both the bile and pancreatic duct had opened into the anterior intestine. Active feeding began in 50% of larvae at 4 DAH, although permanence of yolk reserves until 7 DAH suggests a period of both endogenous and exogenous feeding. Nutrient absorption was first visible from 5 DAH, as colourless supra- and infranuclear vacuoles in the anterior intestinal mucosa, suggesting a lipid content, as well as supranuclear, eosinophilic vacuoles, containing protein, in the posterior intestinal mucosa. Early caecal development could be detected from 10 DAH, whereas gastric glands appeared at 30 DAH, indicating the transition from larval to juvenile stage and the acquisition of an adult mode of digestion. Goblet cells appeared in the digestive tract of sharpsnout sea bream larvae shortly after first feeding. The mucus content of goblet cells varied with the digestive region and, in the buccal cavity and oesophagus, also with the developmental phase. This study provides knowledge for better husbandry practices in the aquaculture industry, as well as for the implementation of future nutritional studies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Fanouraki, E; Papandroulakis, N; Ellis, T; Mylonas, C C; Scott, A P; Pavlidis, M

Water cortisol is a reliable indicator of stress in European sea bass, Dicentrarchus labrax Journal Article

Behaviour, 145 (10), pp. 1267–1281, 2008, ISSN: 00057959.

Abstract | Links | BibTeX

Corriero, A; Medina, A; Mylonas, C C; Santamaria, N; Losurdo, M; Abascal, F J; Spedicato, D; Aprea, A; Bridges, C R; Metrio, De G

Effects of gonadotropin-releasing hormone agonist (GnRHa) administration on male germ cell apoptosis in captive Atlantic bluefin tuna (Thunnus thynnus L.) Journal Article

Cybium, 32 (2 SUPPL.), pp. 203–204, 2008, ISSN: 03990974.

Abstract | Links | BibTeX

Fauvel, C; Suquet, M; Severe, A; Mylonas, C C; Nikos, Papandroulakis N

Slow-release GnRHa treatment prevented atresia during vitellogenesis and induced ovulation of captive wreckfish (Polyprion americanus) Journal Article

Cybium, 32 (2 SUPPL.), pp. 191, 2008, ISSN: 03990974.

Abstract | Links | BibTeX

Marco-Jiménez, F; Peñaranda, D S; Pérez, L; Viudes-De-Castro, M P; Mylonas, C C; Jover, M; Asturiano, J F

Morphometric characterization of sharpsnout sea bream (Diplodus puntazzo) and gilthead sea bream (Sparus aurata) spermatozoa using computer-assisted spermatozoa analysis (ASMA) Journal Article

Journal of Applied Ichthyology, 24 (4), pp. 382–385, 2008, ISSN: 01758659.

Abstract | Links | BibTeX

@article{marco-jimenez_morphometric_2008,
title = {Morphometric characterization of sharpsnout sea bream (Diplodus puntazzo) and gilthead sea bream (Sparus aurata) spermatozoa using computer-assisted spermatozoa analysis (ASMA)},
author = {F Marco-Jiménez and D S Peñaranda and L Pérez and M P Viudes-De-Castro and C C Mylonas and M Jover and J F Asturiano},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-48249111800&doi=10.1111%2fj.1439-0426.2008.01135.x&partnerID=40&md5=61fe013ab1e0956b42816ad0eda4f083},
doi = {10.1111/j.1439-0426.2008.01135.x},
issn = {01758659},
year = {2008},
date = {2008-01-01},
journal = {Journal of Applied Ichthyology},
volume = {24},
number = {4},
pages = {382--385},
abstract = {As part of a larger study on sperm quality and cryopreservation methods, the present study characterized the head morphometry of sharpsnout sea bream (Diplodus puntazzo) and gilthead sea bream (Sparus aurata) spermatozoa, using both scanning electron microscopy (SEM) and computer-assisted morphology analysis (ASMA). The latter method has been used rarely in fish and this is its first application on sharpsnout sea bream and gilthead sea bream spermatozoa. Results obtained using SEM are expensive and time-consuming, while ASMA provides a faster and automated evaluation of morphometric parameters of spermatozoa head. For sharpsnout sea bream spermatozoa, similar head measurement values were obtained using both ASMA and SEM, having a mean ± standard error length of 2.57 ± 0.01 μm vs 2.54 ± 0.02 μm, width of 2.22 ± 0.02 μm vs 2.26 ± 0.04 μm, surface area of 4.44 ± 0.02 μm 2 vs 4.50 ± 0.04 μm 2 and perimeter of 7.70 ± 0.02 μm vs 7.73 ± 0.04 μm using ASMA and SEM, respectively. Although gilthead sea bream spermatozoa were found to be smaller than those of sharpsnout sea bream, spermatozoal head morphometry parameters were also found to be similar regardless of evaluation method, having a mean head length of 1.97 ± 0.01 μm vs 1.94 ± 0.02 μm, head width of 1.80 ± 0.01 μm vs 1.78 ± 0.02 μm, surface area of 3.16 ± 0.03 μm 2 vs 3.18 ± 0.06 μm 2 and perimeter of 6.52 ± 0.04 μm vs 6.56 ± 0.08 μm using ASMA and SEM, respectively. The results demonstrate that ASMA can be considered as a reliable technique for spermatozoal morphology analysis, and can be a useful tool for studies on fish spermatozoa, providing quick and objective results. © 2008 Blackwell Verlag, Berlin.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Papandroulakis, N; Mylonas, C C; Syggelaki, E; Katharios, P; Divanach, P

First reproduction of captive-reared wreckfish (Polyprion americanus) using GnRH implants. Inproceedings

Aquaculture Europe 08, European Aquaculture Society, Krakow, Poland, 2008, (Backup Publisher: European Aquaculture Society).

BibTeX

Duncan, N; Estevez, A; Padros, F; Aguilera, C; Montero, F E; Norambuena, F; Carazo, I; Carbo, R; Mylonas, C C

Acclimation to captivity and GnRHa-induced spawning of meagre (Argyrosomus regius) Journal Article

Cybium, 32 (2 SUPPL.), pp. 332–333, 2008, ISSN: 03990974.

Abstract | Links | BibTeX

2007

Katharios, P; Agathaggelou, A; Paraskevopoulos, S; Mylonas, C C

Comparison of iodine and glutaraldehyde as surface disinfectants for red porgy (Pagrus pagrus) and white sea bream (Diplodus sargus sargus) eggs Journal Article

Aquaculture Research, 38 (5), pp. 527–536, 2007, ISSN: 1355557X.

Abstract | Links | BibTeX

Moles, G; Carrillo, M; Mañanós, E; Mylonas, C C; Zanuy, S

Temporal profile of brain and pituitary GnRHs, GnRH-R and gonadotropin mRNA expression and content during early development in European sea bass (Dicentrarchus labrax L.) Journal Article

General and Comparative Endocrinology, 150 (1), pp. 75–86, 2007, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{moles_temporal_2007,
title = {Temporal profile of brain and pituitary GnRHs, GnRH-R and gonadotropin mRNA expression and content during early development in European sea bass (Dicentrarchus labrax L.)},
author = {G Moles and M Carrillo and E Mañanós and C C Mylonas and S Zanuy},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845327171&doi=10.1016%2fj.ygcen.2006.07.012&partnerID=40&md5=71103ae9c092d705dd91b0d4f7ba5806},
doi = {10.1016/j.ygcen.2006.07.012},
issn = {00166480},
year = {2007},
date = {2007-01-01},
journal = {General and Comparative Endocrinology},
volume = {150},
number = {1},
pages = {75--86},
abstract = {A likely endocrine control mechanism for sexual differentiation in size-graded populations of European sea bass (Dicentrarchus labrax) is proposed by evaluating the brain expression and pituitary content of two forms of gonadotropin-releasing hormone (GnRH), namely sea bream (sbGnRH) and salmon (sGnRH), the pituitary expression of one subtype of GnRH receptor (dlGnRH-R-2A) and the three gonadotropin (GtH) subunits, namely glycoprotein α (GPα), follicle-stimulating hormone β (FSHβ) and luteinizing hormone β (LHβ), as well as the pituitary and plasma LH levels between 50 and 300 days post-hatching (dph). Four gradings were conducted between 2 and 8 months after hatching, resulting in a population of large and small individuals, having 96.5% females (female-dominant population) and 69.2% males (male-dominant population), respectively, after the last grading. The onset of gonadal differentiation was different in the two sexes, and coincided with a peak of expression of sbGnRH or sGnRH. Furthermore, the expression of these GnRHs was correlated with the expression of dlGnRH-R-2A. Sex-related differences in the brain and pituitary content of sbGnRH were also found at the time of sexual differentiation. Moreover, the observed sexual dimorphism at the transcriptional or synthesis level of these GnRH forms suggests that a different neuro-hormonal regulation is operating according to sex. At the onset of sex differentiation, FSHβ transcriptional activity reached maximal values, which were maintained until the completion of the process. The present study suggests a role for sbGnRH, sGnRH and the dlGnRH-R-2A during gonadal differentiation, possibly through enhancement of FSHβ gene expression. In males, a different endocrine regulation seems to exist also during spermiogenesis and spermiation, when gene transcription, peptide synthesis and release of LH are of greater importance. © 2006 Elsevier Inc. All rights reserved.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Agulleiro, M J; Scott, A P; Duncan, N; Mylonas, C C; Cerdà, J

Treatment of GnRHa-implanted Senegalese sole (Solea senegalensis) with 11-ketoandrostenedione stimulates spermatogenesis and increases sperm motility Journal Article

Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology, 147 (4), pp. 885–892, 2007, ISSN: 10956433.

Abstract | Links | BibTeX

@article{agulleiro_treatment_2007,
title = {Treatment of GnRHa-implanted Senegalese sole (Solea senegalensis) with 11-ketoandrostenedione stimulates spermatogenesis and increases sperm motility},
author = {M J Agulleiro and A P Scott and N Duncan and C C Mylonas and J Cerdà},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34249821062&doi=10.1016%2fj.cbpa.2007.02.008&partnerID=40&md5=2de590539379c82501ace5929c501f75},
doi = {10.1016/j.cbpa.2007.02.008},
issn = {10956433},
year = {2007},
date = {2007-01-01},
journal = {Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology},
volume = {147},
number = {4},
pages = {885--892},
abstract = {The effect of 11-ketoandrostenedione (OA) on plasma concentrations of sexual steroids and spermatogenesis of Senegalese sole (Solea senegalensis) implanted with gonadotropin-releasing hormone agonist (GnRHa) was investigated. Males were treated with saline (control) or with GnRHa implants (50 μg kg- 1) in the presence or absence of OA (2 or 7 mg kg- 1) during twenty eight days. Treatment with GnRHa alone slightly stimulated spermatogenesis and milt production with respect to controls, and this was associated with a transient elevation of plasma 11-ketotestosterone (11-KT) at day seven and an increase of 5β-reduced metabolite(s) of 17,20β-dihydroxy-pregn-4-en-3-one (17,20βP) at day twenty eight. However, treatment with GnRHa + OA increased plasma concentrations of 11-KT and free + sulphated 5β-reduced metabolites of 17,20βP at days seven, fourteen and twenty one. After twenty eight days, the testis of GnRHa + OA-treated fish showed a lower number of spermatogonia B and spermatocytes I, and a higher number of spermatids, than fish treated with GnRHa alone. In addition, the motility of spermatozoa produced by GnRHa + OA males was enhanced by 2-fold with respect to controls or GnRHa males. These results suggest that treatment of Senegalese sole with GnRHa + OA stimulates spermatogenesis resulting in more motile sperm. Such effects could be mediated by an increased synthesis of 11-KT and/or 17,20βP in the testis but further studies will be required to elucidate the specific mechanism involved. © 2007 Elsevier Inc. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Corriero, A; Medina, A; Mylonas, C C; Abascal, F J; Deflorio, M; Aragón, L; Bridges, C R; Santamaria, N; Heinisch, G; Vassallo-Agius, R; Belmonte, A; Fauvel, C; Garcia, A; Gordin, H; Metrio, De G

Histological study of the effects of treatment with gonadotropin-releasing hormone agonist (GnRHa) on the reproductive maturation of captive-reared Atlantic bluefin tuna (Thunnus thynnus L.) Journal Article

Aquaculture, 272 (1-4), pp. 675–686, 2007, ISSN: 00448486.

Abstract | Links | BibTeX

@article{corriero_histological_2007,
title = {Histological study of the effects of treatment with gonadotropin-releasing hormone agonist (GnRHa) on the reproductive maturation of captive-reared Atlantic bluefin tuna (Thunnus thynnus L.)},
author = {A Corriero and A Medina and C C Mylonas and F J Abascal and M Deflorio and L Aragón and C R Bridges and N Santamaria and G Heinisch and R Vassallo-Agius and A Belmonte and C Fauvel and A Garcia and H Gordin and G De Metrio},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-35848947039&doi=10.1016%2fj.aquaculture.2007.08.030&partnerID=40&md5=8de85559a67c857278c21ecf2d8faa9f},
doi = {10.1016/j.aquaculture.2007.08.030},
issn = {00448486},
year = {2007},
date = {2007-01-01},
journal = {Aquaculture},
volume = {272},
number = {1-4},
pages = {675--686},
abstract = {The effects of gonadotropin-releasing hormone agonist (GnRHa) administration on the gonads of 66 Atlantic bluefin tuna (Thunnus thynnus L.) reared in floating cages (La Azohía, Murcia, Spain) were evaluated using histological analyses. During two consecutive reproductive seasons (June-July 2004 and 2005), about half of the fish in each cage were administered a GnRHa implant using a spear gun, without being anesthetized or physically restrained, and were sacrificed for sampling 2-8 d later. Rearing for 1-3 years in captivity did not prevent vitellogenesis and oocyte growth, since yolk granule formation and oocyte diameter of fully vitellogenic oocytes were similar to wild fish. However, a lower gonad size and number of vitellogenic oocytes were observed compared to wild spawners. None of the 14 untreated Controls had oocytes at final oocyte maturation (FOM) at the time of sampling and postovulatory follicles (POFs) were observed only in three of them. In addition, a higher volume fraction of atretic oocytes was observed in untreated Controls when compared to the wild or GnRHa-treated fish, indicating a shut-down of reproductive activity at this time. On the contrary, all GnRHa-treated females had oocytes at FOM and/or POFs, with the exception of two fully atretic individuals. In the males, no differences in testicular histology were observed between GnRHa-treated and Control fish, and individuals were at early or late spermatogenesis. The study indicates that wild-caught Atlantic bluefin tuna reared in captivity undergo vitellogenesis and spermatogenesis, but females have a low capacity for spontaneous FOM and ovulation, whereas GnRHa treatment is effective in inducing multiple cycles of FOM and ovulation. © 2007 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Zohar, Y

Promoting oocyte maturation, ovulation and spawning in farmed fish Incollection

Babin, PJ; Cerdà, J; Lubzens, Esther (Ed.): The Fish Oocyte: From Basic Studies to Biotechnological Applications, pp. 437–474, Springer Netherlands, 2007, ISBN: 978-1-4020-6233-9, (Publication Title: The Fish Oocyte: From Basic Studies to Biotechnological Applications).

Abstract | Links | BibTeX

Martins, R S T; Deloffre, L A M; Mylonas, C C; Power, D M; Canário, A V M

Developmental expression of DAX1 in the European sea bass, Dicentrarchus labrax: Lack of evidence for sexual dimorphism during sex differentiation Journal Article

Reproductive Biology and Endocrinology, 5 , 2007, ISSN: 14777827.

Abstract | Links | BibTeX

@article{martins_developmental_2007,
title = {Developmental expression of DAX1 in the European sea bass, Dicentrarchus labrax: Lack of evidence for sexual dimorphism during sex differentiation},
author = {R S T Martins and L A M Deloffre and C C Mylonas and D M Power and A V M Canário},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34250618331&doi=10.1186%2f1477-7827-5-19&partnerID=40&md5=fe5c46e901d1142576a1e6ea05962ebf},
doi = {10.1186/1477-7827-5-19},
issn = {14777827},
year = {2007},
date = {2007-01-01},
journal = {Reproductive Biology and Endocrinology},
volume = {5},
abstract = {Background: DAX1 (NR0B1), a member of the nuclear receptors super family, has been shown to be involved in the genetic sex determination and in gonadal differentiation in several vertebrate species. In the aquaculture fish European sea bass, Dicentrarchus labrax, and in the generality of fish species, the mechanisms of sex determination and differentiation have not been elucidated. The present study aimed at characterizing the European DAX1 gene and its developmental expression at the mRNA level. Methods: A full length European sea bass DAX1 cDNA (sbDAX1) was isolated by screening a testis cDNA library. The structure of the DAX1 gene was determined by PCR and Southern blot. Multisequence alignments and phylogenetic analysis were used to compare the translated sbDAX1 product to that of other vertebrates. sbDAX1 expression was analysed by Northern blot and relative RT-PCR in adult tissues. Developmental expression of mRNA levels was analysed in groups of larvae grown either at 15°C or 20°C (masculinising temperature) during the first 60 days, or two groups of fish selected for fast (mostly females) and slow growth. Results: The sbDAX1 is expressed as a single transcript in testis and ovary encoding a predicted protein of 301 amino acids. A polyglutamine stretch of variable length in different DAX1 proteins is present in the DNA binding domain. The sbDAX1 gene is composed of two exons, separated by a single 283 bp intron with conserved splice sites in same region of the ligand binding domain as other DAX1 genes. sbDAX1 mRNA is not restricted to the brain-pituitary-gonadal axis and is also detected in the gut, heart, gills, muscle and kidney. sbDAX1 mRNA was detected as early as 4 days post hatching (dph) and expression was not affected by incubation temperature. Throughout gonadal sex differentiation (60-300 dph) no dimorphic pattern of expression was observed. Conclusion: The sbDAX1 gene and putative protein coding region is highly conserved and has a wide pattern of tissue expression. Although gene expression data suggests sbDAX1 to be important for the development and differentiation of the gonads, it is apparently not sex specific. © 2007 Martins et al; licensee BioMed Central Ltd.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Background: DAX1 (NR0B1), a member of the nuclear receptors super family, has been shown to be involved in the genetic sex determination and in gonadal differentiation in several vertebrate species. In the aquaculture fish European sea bass, Dicentrarchus labrax, and in the generality of fish species, the mechanisms of sex determination and differentiation have not been elucidated. The present study aimed at characterizing the European DAX1 gene and its developmental expression at the mRNA level. Methods: A full length European sea bass DAX1 cDNA (sbDAX1) was isolated by screening a testis cDNA library. The structure of the DAX1 gene was determined by PCR and Southern blot. Multisequence alignments and phylogenetic analysis were used to compare the translated sbDAX1 product to that of other vertebrates. sbDAX1 expression was analysed by Northern blot and relative RT-PCR in adult tissues. Developmental expression of mRNA levels was analysed in groups of larvae grown either at 15°C or 20°C (masculinising temperature) during the first 60 days, or two groups of fish selected for fast (mostly females) and slow growth. Results: The sbDAX1 is expressed as a single transcript in testis and ovary encoding a predicted protein of 301 amino acids. A polyglutamine stretch of variable length in different DAX1 proteins is present in the DNA binding domain. The sbDAX1 gene is composed of two exons, separated by a single 283 bp intron with conserved splice sites in same region of the ligand binding domain as other DAX1 genes. sbDAX1 mRNA is not restricted to the brain-pituitary-gonadal axis and is also detected in the gut, heart, gills, muscle and kidney. sbDAX1 mRNA was detected as early as 4 days post hatching (dph) and expression was not affected by incubation temperature. Throughout gonadal sex differentiation (60-300 dph) no dimorphic pattern of expression was observed. Conclusion: The sbDAX1 gene and putative protein coding region is highly conserved and has a wide pattern of tissue expression. Although gene expression data suggests sbDAX1 to be important for the development and differentiation of the gonads, it is apparently not sex specific. © 2007 Martins et al; licensee BioMed Central Ltd.

Socorro, S; Martins, R S; Deloffre, L; Mylonas, C C; Canario, A V M

A cDNA for European sea bass (Dicentrachus labrax) 11β-hydroxylase: Gene expression during the thermosensitive period and gonadogenesis Journal Article

General and Comparative Endocrinology, 150 (1), pp. 164–173, 2007, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{socorro_cdna_2007,
title = {A cDNA for European sea bass (Dicentrachus labrax) 11β-hydroxylase: Gene expression during the thermosensitive period and gonadogenesis},
author = {S Socorro and R S Martins and L Deloffre and C C Mylonas and A V M Canario},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845192413&doi=10.1016%2fj.ygcen.2006.07.018&partnerID=40&md5=c6f180cf4e2308552b2e4c7024ef3a29},
doi = {10.1016/j.ygcen.2006.07.018},
issn = {00166480},
year = {2007},
date = {2007-01-01},
journal = {General and Comparative Endocrinology},
volume = {150},
number = {1},
pages = {164--173},
abstract = {Steroid P450 11β-hydroxylase, encoded by the CYP11B gene, is a key mitochondrial enzyme for the production of 11-oxygenated androgens, which have been shown to be potent masculinising steroids in several fish species. In this study we have isolated a CYP11B cDNA of 1903 base pairs from the testis of European sea bass (Dicentrarchus labrax) encoding a predicted protein of 552 amino acids. The amino acid identities to other vertebrate 11β-hydroxylase proteins ranged from 66% to 72% to other fish; 45% to amphibian and 35-39% to mammalian. Southern blot indicated that a single CYP11B gene is present. Northern blot analysis detected two transcripts in testis and head kidney, one of the same size of the isolated clone and the other of 3.9 kb. Reverse transcriptase-polymerase chain reaction showed abundant mRNA expression only in testis and head kidney, being residual in a range of other tissues. Expression of CYP11B and CYP19A (which encodes for ovarian aromatase) was detected from at least 4 days post-hatching and did not appear to be affected by rearing temperature (15 and 20 °C) during the first 60 days, a period in which high temperatures promote masculinisation in European sea bass. Throughout, gonadogenesis (60-300 dph), a highly dimorphic pattern of CYP11B expression was consistent with a role of this gene in testicular development. © 2006 Elsevier Inc. All rights reserved.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Katharios, P; Garaffo, M; Sarter, K; Athanassopoulou, F; Mylonas, C C

A case of high mortality due to heavy infestation of Ceratomyxa diplodae in sharpsnout sea bream (Diplodus puntazzo) treated with reproductive steroids Journal Article

Bulletin of the European Association of Fish Pathologists, 27 (1), pp. 43–47, 2007, ISSN: 01080288.

Abstract | Links | BibTeX

Mylonas, C C; Bridges, C; Gordin, H; Ríos, A B; García, A; Gándara, De La F; Fauvel, C; Suquet, M; Medina, A; Papadaki, M; Heinisch, G; Metrio, De G; Corriero, A; Vassallo-Agius, R; Guzmán, J -M; Mañanos, E; Zohar, Y

Preparation and administration of gonadotropin-releasing hormone agonist (GnRHa) implants for the artificial control of reproductive maturation in captive-reared Atlantic bluefin tuna (Thunnus thynnus thynnus) Journal Article

Reviews in Fisheries Science, 15 (3), pp. 183–210, 2007, ISSN: 10641262.

Abstract | Links | BibTeX

@article{mylonas_preparation_2007,
title = {Preparation and administration of gonadotropin-releasing hormone agonist (GnRHa) implants for the artificial control of reproductive maturation in captive-reared Atlantic bluefin tuna (Thunnus thynnus thynnus)},
author = {C C Mylonas and C Bridges and H Gordin and A B Ríos and A García and F De La Gándara and C Fauvel and M Suquet and A Medina and M Papadaki and G Heinisch and G De Metrio and A Corriero and R Vassallo-Agius and J -M Guzmán and E Mañanos and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-35648987213&doi=10.1080%2f10641260701484572&partnerID=40&md5=e9c5bc33d2bd695220a31847ed892503},
doi = {10.1080/10641260701484572},
issn = {10641262},
year = {2007},
date = {2007-01-01},
journal = {Reviews in Fisheries Science},
volume = {15},
number = {3},
pages = {183--210},
abstract = {Mature migrating Atlantic bluefin tuna (Thunnus thynnus thynnus) were captured in the Mediterranean Sea with a purse seine and reared in floating cages for 2 to 3 years. During the natural spawning period (June-July) of two consecutive years, fish were randomly implanted underwater with a controlled-release delivery system (implant) loaded with gonadotropin-releasing hormone agonist (GnRHa), in order to induce final oocyte maturation (FOM), ovulation/spermiation, and spawning. At the time of sampling, males were significantly larger than females (ANOVA, P 0.001), having a mean ( SE) fork length and body weight of 190 3 cm and 122 5 kg, compared to 176 3 cm and 94 4 kg of females, respectively. All fish were reproductively mature, with their age ranging between 5 and 12 years and males being a year older, on average. After GnRHa implantation, fish were monitored for spawning and the release of eggs, and were sacrificed at different times after hormone treatment in order to examine the progressive effect of the treatment on gonad maturation. The in vitro GnRHa release from the produced implants was maximal during the first 2 d, with a mean ( SE) release of 525 166 g GnRHa implant-1 day-1. The plasma GnRHa profile in vivo reflected the release in vitro, and statistically significant elevations in plasma GnRHa levels were measured until 7 d after treatment (ANOVA, P 0.01). The underwater implantation procedure was improved between 2004 and 2005, requiring an average ( SD) of 3.1 1.4 min for each fish, and was 64 and 84% successful in 2004 and 2005, respectively. There were no differences between the histological appearance of the testes of GnRHa-treated and control males, and almost all of them contained intra-testicular spermatozoa. However, the proportion of spermiating control males (n = 17) was only 12% compared to 26% for the GnRHa-implanted males (n = 19). Also, there were no differences between controls and GnRHa-implanted fish in sperm concentration, initial spermatozoa motility, or duration of forward motility, which ranged between 29.02-48.54 1010 spermatozoa ml-1, 58-63% and 8-9 min, respectively. Final oocyte maturation (FOM) and post-ovulatory follicles (POFs) occurred in 63% and 88%, respectively, of the GnRHa implanted females (n = 16), compared to 0% and 21%, respectively, of the control females (n = 14). In addition, two GnRHa-implanted females in 2005 were found to be ovulated at the time of sacrifice, and their eggs were fertilized in vitro with sperm from spermiating males, which resulted in viable embryos and larvae. Finally, although spawning was not observed, fertilized eggs were collected from the cages. Larvae produced from these eggs were identified as Atlantic bluefin tuna, demonstrating that the present GnRHa implantation method can be used to induce FOM, ovulation/spermiation, and spawning in captive-reared Atlantic bluefin tuna. Copyright © Taylor & Francis Group, LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mature migrating Atlantic bluefin tuna (Thunnus thynnus thynnus) were captured in the Mediterranean Sea with a purse seine and reared in floating cages for 2 to 3 years. During the natural spawning period (June-July) of two consecutive years, fish were randomly implanted underwater with a controlled-release delivery system (implant) loaded with gonadotropin-releasing hormone agonist (GnRHa), in order to induce final oocyte maturation (FOM), ovulation/spermiation, and spawning. At the time of sampling, males were significantly larger than females (ANOVA, P 0.001), having a mean ( SE) fork length and body weight of 190 3 cm and 122 5 kg, compared to 176 3 cm and 94 4 kg of females, respectively. All fish were reproductively mature, with their age ranging between 5 and 12 years and males being a year older, on average. After GnRHa implantation, fish were monitored for spawning and the release of eggs, and were sacrificed at different times after hormone treatment in order to examine the progressive effect of the treatment on gonad maturation. The in vitro GnRHa release from the produced implants was maximal during the first 2 d, with a mean ( SE) release of 525 166 g GnRHa implant-1 day-1. The plasma GnRHa profile in vivo reflected the release in vitro, and statistically significant elevations in plasma GnRHa levels were measured until 7 d after treatment (ANOVA, P 0.01). The underwater implantation procedure was improved between 2004 and 2005, requiring an average ( SD) of 3.1 1.4 min for each fish, and was 64 and 84% successful in 2004 and 2005, respectively. There were no differences between the histological appearance of the testes of GnRHa-treated and control males, and almost all of them contained intra-testicular spermatozoa. However, the proportion of spermiating control males (n = 17) was only 12% compared to 26% for the GnRHa-implanted males (n = 19). Also, there were no differences between controls and GnRHa-implanted fish in sperm concentration, initial spermatozoa motility, or duration of forward motility, which ranged between 29.02-48.54 1010 spermatozoa ml-1, 58-63% and 8-9 min, respectively. Final oocyte maturation (FOM) and post-ovulatory follicles (POFs) occurred in 63% and 88%, respectively, of the GnRHa implanted females (n = 16), compared to 0% and 21%, respectively, of the control females (n = 14). In addition, two GnRHa-implanted females in 2005 were found to be ovulated at the time of sacrifice, and their eggs were fertilized in vitro with sperm from spermiating males, which resulted in viable embryos and larvae. Finally, although spawning was not observed, fertilized eggs were collected from the cages. Larvae produced from these eggs were identified as Atlantic bluefin tuna, demonstrating that the present GnRHa implantation method can be used to induce FOM, ovulation/spermiation, and spawning in captive-reared Atlantic bluefin tuna. Copyright © Taylor & Francis Group, LLC.

2006

Sarter, K; Papadaki, M; Zanuy, S; Mylonas, C C

Permanent sex inversion in 1-year-old juveniles of the protogynous dusky grouper (Epinephelus marginatus) using controlled-release 17α-methyltestosterone implants Journal Article

Aquaculture, 256 (1-4), pp. 443–456, 2006, ISSN: 00448486.

Abstract | Links | BibTeX

@article{sarter_permanent_2006,
title = {Permanent sex inversion in 1-year-old juveniles of the protogynous dusky grouper (Epinephelus marginatus) using controlled-release 17α-methyltestosterone implants},
author = {K Sarter and M Papadaki and S Zanuy and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646896490&doi=10.1016%2fj.aquaculture.2006.01.034&partnerID=40&md5=fae7d76571a7060e8182bf08f6c00e7e},
doi = {10.1016/j.aquaculture.2006.01.034},
issn = {00448486},
year = {2006},
date = {2006-01-01},
journal = {Aquaculture},
volume = {256},
number = {1-4},
pages = {443--456},
abstract = {Long-term treatments (April-June 2004) with 17α-methyltestosterone (MT) and/or human chorionic gonadotropin (hCG) were used to induce precocious sex change in 1-year-old juveniles (mean ± SD body weight of 131 ± 25 g) of the protogynous dusky grouper (Epinephelus marginatus). The MT treatment was given once a month using controlled-release implants (1.5 mg per implant, ∼11 mg kg- 1 body weight), whereas hCG was injected intramuscularly once a month (MT/hCG group) or every 2 weeks (hCG group). In vitro mean (± SEM) daily and total MT release from the implants was 22.6 ± 5.4 μg day- 1 implant- 1 and 686 ± 113 μg implant- 1, respectively. In vivo, plasma MT levels of European sea bas (Dicentrarchus labrax) used as model fish (203 ± 41 g body weight) and given a single MT implant were 18.5 ± 0.5 ng ml- 1 one day after implantation, declined to 9.6 ± 2.7 ng ml- 1 by day 11 and remained stable between 7.9 and 5.5 ng ml- 1 until day 32. Plasma MT levels were significantly elevated (2-way ANOVA, P < 0.01) in dusky grouper juveniles in response to the MT treatment, both 6 and 12 weeks after beginning the treatment. On the contrary, no significant differences (2-way ANOVA, P > 0.05) between MT/hCG-treated and control fish were observed in plasma testosterone (T) or 11-keto T (11-KT). Pituitary luteinizing hormone (LH) content was significantly lower in both the MT/hCG and hCG groups, compared to controls (2-way ANOVA, P < 0.001), while plasma LH was below detection limits in all treatments. At the onset of the experiment all but one fish were already differentiated into females, having ovaries with primary oocytes. No signs of vitellogenesis or sex inversion were observed in fish from the control and hCG groups during the study. On the contrary, the MT implants induced complete sex change after 12 weeks, with the gonads organized in lobules and cysts filled with germ cells at all stages of spermatogenesis, including spermatozoa. This sex inversion was permanent and fish underwent complete spermatogenesis again during the following year. The results demonstrate that the produced MT-implants, but not the hCG injections, were highly efficient in inducing both sex inversion and complete spermatogenesis in pre-pubertal dusky grouper at the completion of their second year in life. Production of male fish at such an early age may dramatically reduce by many years the time required for natural puberty, sex inversion and the production of sperm by dusky grouper reared under culture conditions. © 2006 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Long-term treatments (April-June 2004) with 17α-methyltestosterone (MT) and/or human chorionic gonadotropin (hCG) were used to induce precocious sex change in 1-year-old juveniles (mean ± SD body weight of 131 ± 25 g) of the protogynous dusky grouper (Epinephelus marginatus). The MT treatment was given once a month using controlled-release implants (1.5 mg per implant, ∼11 mg kg- 1 body weight), whereas hCG was injected intramuscularly once a month (MT/hCG group) or every 2 weeks (hCG group). In vitro mean (± SEM) daily and total MT release from the implants was 22.6 ± 5.4 μg day- 1 implant- 1 and 686 ± 113 μg implant- 1, respectively. In vivo, plasma MT levels of European sea bas (Dicentrarchus labrax) used as model fish (203 ± 41 g body weight) and given a single MT implant were 18.5 ± 0.5 ng ml- 1 one day after implantation, declined to 9.6 ± 2.7 ng ml- 1 by day 11 and remained stable between 7.9 and 5.5 ng ml- 1 until day 32. Plasma MT levels were significantly elevated (2-way ANOVA, P < 0.01) in dusky grouper juveniles in response to the MT treatment, both 6 and 12 weeks after beginning the treatment. On the contrary, no significant differences (2-way ANOVA, P > 0.05) between MT/hCG-treated and control fish were observed in plasma testosterone (T) or 11-keto T (11-KT). Pituitary luteinizing hormone (LH) content was significantly lower in both the MT/hCG and hCG groups, compared to controls (2-way ANOVA, P < 0.001), while plasma LH was below detection limits in all treatments. At the onset of the experiment all but one fish were already differentiated into females, having ovaries with primary oocytes. No signs of vitellogenesis or sex inversion were observed in fish from the control and hCG groups during the study. On the contrary, the MT implants induced complete sex change after 12 weeks, with the gonads organized in lobules and cysts filled with germ cells at all stages of spermatogenesis, including spermatozoa. This sex inversion was permanent and fish underwent complete spermatogenesis again during the following year. The results demonstrate that the produced MT-implants, but not the hCG injections, were highly efficient in inducing both sex inversion and complete spermatogenesis in pre-pubertal dusky grouper at the completion of their second year in life. Production of male fish at such an early age may dramatically reduce by many years the time required for natural puberty, sex inversion and the production of sperm by dusky grouper reared under culture conditions. © 2006 Elsevier B.V. All rights reserved.

Agulleiro, M J; Anguis, V; Cañavate, J P; Martínez-Rodríguez, G; Mylonas, C C; Cerdà, J

Induction of spawning of captive-reared Senegal sole (Solea senegalensis) using different administration methods for gonadotropin-releasing hormone agonist Journal Article

Aquaculture, 257 (1-4), pp. 511–524, 2006, ISSN: 00448486.

Abstract | Links | BibTeX

@article{agulleiro_induction_2006,
title = {Induction of spawning of captive-reared Senegal sole (Solea senegalensis) using different administration methods for gonadotropin-releasing hormone agonist},
author = {M J Agulleiro and V Anguis and J P Cañavate and G Martínez-Rodríguez and C C Mylonas and J Cerdà},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33744478945&doi=10.1016%2fj.aquaculture.2006.02.001&partnerID=40&md5=2c10889e6bad052483983bc9ef891f55},
doi = {10.1016/j.aquaculture.2006.02.001},
issn = {00448486},
year = {2006},
date = {2006-01-01},
journal = {Aquaculture},
volume = {257},
number = {1-4},
pages = {511--524},
abstract = {Captive-reared Senegal sole were treated with intramuscular injection or sustained-release implants of gonadotropin-releasing hormone agonist [D-Ala6, Pro9, NEt] GnRHa (GnRHa) to induce spermiation and spawning. Fish were treated with GnRHa during spring (April-May) or autumn (October), the natural spawning seasons known to occur in wild Senegal sole. During spring, females injected with a dose of 5 μg GnRHa kg- 1 three times a week, or treated with a single GnRHa-loaded implant (50 μg kg- 1) showed multiple ovulations and spawns within a period of approximately 30 days. Plasma levels of 17β-estradiol (E2) were elevated at 7 days post-treatment, preceding the spawns with the highest fecundity, concomitant with a decrease in the levels of plasma testosterone (T). During autumn, however, females changed their responsiveness to GnRHa treatment, a dose of 5 μg kg- 1 being ineffective in inducing spawning, while a dose of 1 μg kg- 1 induced a few spawns. Accordingly, plasma E2 levels showed a small increase after injection of 1 μg kg- 1 GnRHa. In contrast to females, GnRHa injection or implantation in males was ineffective in enhancing spermiation or milt production, regardless of the season when the treatments were applied. However, GnRHa treatment in males increased plasma levels of T and 11-ketotestosterone (11-KT) during spring, while in autumn the levels of plasma androgens decreased after GnRHa injection. These results show that administration of GnRHa during spring either by injection or sustained-release implants induces multiple spawns in captive Senegal sole, although these treatments were ineffective in inducing or enhancing sperm production in males. © 2006 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Zaiss, M M; Papadakis, I E; Maingot, E; Divanach, P; Mylonas, C C

Ontogeny of the digestive tract in shi drum (Umbrina cirrosa L.) reared using the mesocosm larval rearing system Journal Article

Aquaculture, 260 (1-4), pp. 357–368, 2006, ISSN: 00448486.

Abstract | Links | BibTeX

@article{zaiss_ontogeny_2006,
title = {Ontogeny of the digestive tract in shi drum (Umbrina cirrosa L.) reared using the mesocosm larval rearing system},
author = {M M Zaiss and I E Papadakis and E Maingot and P Divanach and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33747800319&doi=10.1016%2fj.aquaculture.2006.06.001&partnerID=40&md5=4f7c6eb4f3932426b7e5fb62cafa6f95},
doi = {10.1016/j.aquaculture.2006.06.001},
issn = {00448486},
year = {2006},
date = {2006-01-01},
journal = {Aquaculture},
volume = {260},
number = {1-4},
pages = {357--368},
abstract = {Histological changes of the digestive tract were studied in shi drum (Umbrina cirrosa) from hatching until 41 days post hatching (dph), when the fry had a mean (±S.D.) total length (TL) of 32 ± 2 mm and wet weight (WW) of 0.42 ± 0.07 g. Larvae were reared using the mesocosm technique, the most natural among commercially employed rearing methods for marine larvae. Shi drum opened their mouth at 2 dph (2.78 ± 0.09 mm TL), at which time 90% of the larvae already had an inflated swim bladder. The differentiation of the digestive tract into buccopharynx, esophagus, and anterior and posterior intestine was completed by 3 dph (2.82 ± 0.07 mm TL), 1 day after the onset of exogenous feeding. The alimentary canal started coiling and formed its first loop at 2 dph, while the pancreas and liver were differentiated at 3 dph. Yolk sac reserves lasted until 7 dph (4.3 ± 0.1 mm TL), suggesting a brief period of endogenous and exogenous feeding. The first esophageal goblet cells appeared at 7 dph containing acid mucins and at 8 dph taste buds appeared on the buccopharyngeal epithelium. The stomach was morphologically differentiated at 9 dph (5.5 ± 0.1 mm TL) when gastric glands became abundant in the cardiac region, and the first pyloric caeca appeared at 14 dph (10.1 ± 0.9 mm TL). Supranuclear eosinophilic vacuoles were observed in the posterior intestine between 3 and 11 dph (6.3 ± 0.9 mm TL). Their number decreased as the stomach differentiated, suggesting a change in the protein digestion mechanism. The results of the study suggest a rapid development of shi drum and its digestive system and underline the possibility of weaning larvae to artificial feed even earlier than the 12 dph employed in the present study. © 2006 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Katharios, P; Garaffo, M; Sarter, K; Poulou, Athanasso F; Mylonas, C C; Divanach, P

Mortality of steroid-treated sharpsnout sea bream Diplodus puntazzo caused by Ceratomyxa diplodae (Protozoa: Myxosporea). Inproceedings

Fifth International Symposium on Aquatic Animal Health, pp. 148, San Francisco, U.S., 2006.

BibTeX

Franch, R; Louro, B; Tsalavouta, M; Chatziplis, D; Tsigenopoulos, C S; Sarropoulou, E; Antonello, J; Magoulas, A; Mylonas, C C; Babbucci, M; Patarnello, T; Power, D M; Kotoulas, G; Bargelloni, L

A genetic linkage map of the hermaphrodite teleost fish Sparus aurata L. Journal Article

Genetics, 174 (2), pp. 851–861, 2006, ISSN: 00166731.

Abstract | Links | BibTeX

@article{franch_genetic_2006,
title = {A genetic linkage map of the hermaphrodite teleost fish Sparus aurata L.},
author = {R Franch and B Louro and M Tsalavouta and D Chatziplis and C S Tsigenopoulos and E Sarropoulou and J Antonello and A Magoulas and C C Mylonas and M Babbucci and T Patarnello and D M Power and G Kotoulas and L Bargelloni},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33750471928&doi=10.1534%2fgenetics.106.059014&partnerID=40&md5=5223c21cec86860a04d8be5eff57e24c},
doi = {10.1534/genetics.106.059014},
issn = {00166731},
year = {2006},
date = {2006-01-01},
journal = {Genetics},
volume = {174},
number = {2},
pages = {851--861},
abstract = {The gilthead sea bream (Sparus aurata L.) is a marine fish of great importance for fisheries and aquaculture. It has also a peculiar sex-determination system, being a protandrous hermaphrodite. Here we report the construction of a first-generation genetic linkage map for S. aurata, based on 204 microsatellite markers. Twenty-six linkage groups (LG) were found. The total map length was 1241.9 cM. The ratio between sex-specific map lengths was 1:1.2 (male:female). Comparison with a preliminary radiation hybrid (RH) map reveals a good concordance, as all markers located in a single LG are located in a single RH group, except for Ad-25 and CId-31. Comparison with the Tetraodon nigroviridis genome revealed a considerable number of evolutionary conserved regions (ECRs) between the two species. The mean size of ECRs was 182 bp (sequence identity 60-90%). Forty-one ECRs have a known chromosomal location in the pufferfish genome. Despite the limited number of anchoring points, significant syntenic relationships were found. The linkage map presented here provides a robust comparative framework for QTL analysis in S. aurata and is a step toward the identification of genetic loci involved both in the determination of economically important traits and in the individual timing of sex reversal. Copyright © 2006 by the Genetics Society of America.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2005

Mylonas, C C; Cardinaletti, G; Sigelaki, I; Polzonetti-Magni, A

Comparative efficacy of clove oil and 2-phenoxyethanol as anesthetics in the aquaculture of European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) at different temperatures Journal Article

Aquaculture, 246 (1-4), pp. 467–481, 2005, ISSN: 00448486, (Publisher: Elsevier).

Abstract | Links | BibTeX

@article{mylonas_comparative_2005,
title = {Comparative efficacy of clove oil and 2-phenoxyethanol as anesthetics in the aquaculture of European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) at different temperatures},
author = {C C Mylonas and G Cardinaletti and I Sigelaki and A Polzonetti-Magni},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-17944372332&doi=10.1016%2fj.aquaculture.2005.02.046&partnerID=40&md5=c28d66ffa819306390f68fb47b57ced5},
doi = {10.1016/j.aquaculture.2005.02.046},
issn = {00448486},
year = {2005},
date = {2005-01-01},
journal = {Aquaculture},
volume = {246},
number = {1-4},
pages = {467--481},
abstract = {The efficacy of clove oil as an anesthetic was evaluated in juvenile European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata), and was compared to the commonly used 2-phenoxyethanol through a series of experiments simulating aquaculture activities. Firstly, using as a criterion the acquisition of complete anesthesia (stage A5) in < 3 min and recovery (stage R5) in < 10 min, the optimal doses at 25°C were determined to be 40 mg l-1 of clove oil for both species, and 350 mg l-1 and 300 mg l-1 of 2-phenoxyethanol for European sea bass and gilthead sea bream, respectively. At 15°C, the optimal doses for the European sea bass were determined to be around 30 mg l-1 clove oil and 300 mg l -1 2-phenoxyethanol, and for gilthead sea bream 55 mg l-1 clove oil and 450 mg l-1 2-phenoxyethanol. Increasing the exposure time of fish to the optimal anesthetic dose for 5, 10 or 15 min after stage A5 anesthesia prolonged recovery time (ANOVA, P < 0.001), especially in gilthead sea bream, which also suffered significant mortality (10-83%). As expected, the lower temperature resulted in significantly longer anesthesia induction and recovery times (ANOVA, P < 0.001), presumably due to the positive relationship between temperature, and opercular ventilation rates (ANOVA, P < 0.001) and metabolism. Finally, repeated exposure to anesthetics at 0 h, 3 h and 24 h increased significantly the induction time to stage A5 anesthesia (ANOVA, P < 0.001), suggesting the development of a slight tolerance, especially to the clove oil. The study demonstrated that clove oil can be used as an effective anesthetic in European sea bass and gilthead sea bream aquaculture, at almost 10-fold lower doses than 2-phenoxyethanol. The observed differences in (a) dose response, (b) anesthesia induction and recovery times, (c) ventilation rates and (d) mortality after prolonged exposure among the two species, underscore the need to undertake extensive studies with the specific fish species, anesthetic and experimental procedure employed, before clove oil or any other anesthetic is proposed for commercial use in an aquaculture species. © 2005 Elsevier B.V. All rights reserved.},
note = {Publisher: Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The efficacy of clove oil as an anesthetic was evaluated in juvenile European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata), and was compared to the commonly used 2-phenoxyethanol through a series of experiments simulating aquaculture activities. Firstly, using as a criterion the acquisition of complete anesthesia (stage A5) in < 3 min and recovery (stage R5) in < 10 min, the optimal doses at 25°C were determined to be 40 mg l-1 of clove oil for both species, and 350 mg l-1 and 300 mg l-1 of 2-phenoxyethanol for European sea bass and gilthead sea bream, respectively. At 15°C, the optimal doses for the European sea bass were determined to be around 30 mg l-1 clove oil and 300 mg l -1 2-phenoxyethanol, and for gilthead sea bream 55 mg l-1 clove oil and 450 mg l-1 2-phenoxyethanol. Increasing the exposure time of fish to the optimal anesthetic dose for 5, 10 or 15 min after stage A5 anesthesia prolonged recovery time (ANOVA, P < 0.001), especially in gilthead sea bream, which also suffered significant mortality (10-83%). As expected, the lower temperature resulted in significantly longer anesthesia induction and recovery times (ANOVA, P < 0.001), presumably due to the positive relationship between temperature, and opercular ventilation rates (ANOVA, P < 0.001) and metabolism. Finally, repeated exposure to anesthetics at 0 h, 3 h and 24 h increased significantly the induction time to stage A5 anesthesia (ANOVA, P < 0.001), suggesting the development of a slight tolerance, especially to the clove oil. The study demonstrated that clove oil can be used as an effective anesthetic in European sea bass and gilthead sea bream aquaculture, at almost 10-fold lower doses than 2-phenoxyethanol. The observed differences in (a) dose response, (b) anesthesia induction and recovery times, (c) ventilation rates and (d) mortality after prolonged exposure among the two species, underscore the need to undertake extensive studies with the specific fish species, anesthetic and experimental procedure employed, before clove oil or any other anesthetic is proposed for commercial use in an aquaculture species. © 2005 Elsevier B.V. All rights reserved.

Mylonas, C C; Anezaki, L; Divanach, P; Zanuy, S; Piferrer, F; Ron, B; Peduel, A; Atia, Ben I; Gorshkov, S; Tandler, A

Influence of rearing temperature during the larval and nursery periods on growth and sex differentiation in two Mediterranean strains of Dicentrarchus labrax Journal Article

Journal of Fish Biology, 67 (3), pp. 652–668, 2005, ISSN: 00221112.

Abstract | Links | BibTeX

Koumoundouros, G; Kouttouki, S; Georgakopoulou, E; Papadakis, I; Maingot, E; Kaspiris, P; Kiriakou, Y; Georgiou, G; Divanach, P; Kentouri, M; Mylonas, C C

Ontogeny of the shi drum Umbrina cirrosa (Linnaeus 1758), a candidate new species for aquaculture Journal Article

Aquaculture Research, 36 (13), pp. 1265–1272, 2005, ISSN: 1355557X.

Abstract | Links | BibTeX

Papadaki, M; Piferrer, F; Zanuy, S; Maingot, E; Divanach, P; Mylonas, C C

Growth, sex differentiation and gonad and plasma levels of sex steroids in male- and female-dominant populations of Dicentrarchus labrax obtained through repeated size grading Journal Article

Journal of Fish Biology, 66 (4), pp. 938–956, 2005, ISSN: 00221112, (Publisher: Blackwell Publishing Ltd).

Abstract | Links | BibTeX

Kokokiris, L; Canario, A; Mylonas, C; Pavlidis, M; Kentouri, M; Divanach, P

Induction of ovulation and spawning in the Mediterranean Red Porgy, Pagrus Pagrus, by controlled delivery and acute injection of GnRHa Journal Article

Israeli Journal of Aquaculture - Bamidgeh, 57 (4), pp. 223–230, 2005, ISSN: 0792156X.

Abstract | Links | BibTeX

@article{kokokiris_induction_2005,
title = {Induction of ovulation and spawning in the Mediterranean Red Porgy, Pagrus Pagrus, by controlled delivery and acute injection of GnRHa},
author = {L Kokokiris and A Canario and C Mylonas and M Pavlidis and M Kentouri and P Divanach},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-29744437550&partnerID=40&md5=fe674a5bea66c6aa820eb3a5b7d62661},
issn = {0792156X},
year = {2005},
date = {2005-01-01},
journal = {Israeli Journal of Aquaculture - Bamidgeh},
volume = {57},
number = {4},
pages = {223--230},
abstract = {Gonadotropin-releasing hormone analogue (GnRHa) in the form of saline injections or sustained-release microspheres was used to induce oocyte maturation, ovulation, and spawning in captive red porgy (Pagrus pagrus). Individually tagged vitellogenic females (n = 9 or 10) were treated at the beginning of the spawning season (March) with 20 μg/kg body weight (bw) GnRHa-loaded microspheres, a single injection of 20 μg/ kg bw dissolved in saline, or physiological saline (control). Females were placed in tanks (one tank per treatment) connected to overflow egg collectors and monitored for 11 days. In addition to the eggs collected from the tank overflow, eggs were stripped from the fish on a daily basis. Only one spawn was obtained from the control fish, probably from a single female, given the small relative fecundity (700 eggs/kg bw). On the contrary, treatment with a GnRHa injection produced two spawns (9 and 11 days after treatment) and 50% of the fish ovulated. Treatment with GnRHa microspheres induced seven spawns (3 and 6-11 days after treatment) and 100% of the females ovulated. Females did not spawn all the eggs ovulated on a particular day, evident from the significant number of eggs obtained by manual stripping. Egg quality did not significantly differ among treatments, whereas number of spawned eggs and total relative fecundity were significantly higher in fish treated with GnRHa microspheres (ANOVA, ptextless0.05). The results demonstrate the potential of GnRHa-loaded microspheres to induce spawning in red porgy, as a method of overcoming spawning failures in commercial hatcheries.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Papandroulakis, N; Mylonas, C C; Maingot, E; Divanach, P

First results of greater amberjack (Seriola dumerili) larval rearing in mesocosm Journal Article

Aquaculture, 250 (1-2), pp. 155–161, 2005, ISSN: 00448486.

Abstract | Links | BibTeX

@article{papandroulakis_first_2005,
title = {First results of greater amberjack (Seriola dumerili) larval rearing in mesocosm},
author = {N Papandroulakis and C C Mylonas and E Maingot and P Divanach},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-27344450721&doi=10.1016%2fj.aquaculture.2005.02.036&partnerID=40&md5=85aba7698333eb1cdf77b60229a40d1b},
doi = {10.1016/j.aquaculture.2005.02.036},
issn = {00448486},
year = {2005},
date = {2005-01-01},
journal = {Aquaculture},
volume = {250},
number = {1-2},
pages = {155--161},
abstract = {Species diversification is considered a major approach for the sustainable development of aquaculture. The greater amberjack (Seriola dumerili) has particular characteristics-advantages making it an appropriate candidate: high growth rate, large size, and established worldwide market. In the present study, the mesocosm method for larval rearing was applied, since it has been shown to be effective in the larval rearing of several species so far. This method is a semi-intensive technology, based on daily exogenous food addition, but also having the capacity of some endogenous productivity. Greater amberjack eggs were obtained from wild-caught fish matured in captivity in 6 years, after induced spawning with implants containing gonadotropin-releasing hormone agonist (GnRHa). A total of 9800 eggs survived after embryo appearance and were incubated in a 40-m3 tank with natural seawater of 40 psu. Rearing lasted 40 days. After mouth opening on day 2 post hatching, exogenous feeding with rotifers, Artemia nauplii and inert feed was initiated, while endogenous produced copepods contributed as food for the larvae from day 7 post hatching onwards. During rearing, larvae grew with an exponential rate of 0.073 day -1 in terms of total length (TL), and reached 39.9 ± 5.4 mm and 0.5 ± 0.1 g body weight at the end of the trial. All larvae inflated their swim bladder and completed metamorphosis at about 5 mm and 8 mm TL, respectively. Schooling behavior was first observed when larvae reached 9-10 mm TL, while aggression against the smallest individuals was first noticed the same period. The final population of about 350 individuals (3.5% survival) was transferred at the end of the trial for subsequent on-growing. The results obtained indicate the reliability of the technology for the larval rearing of the greater amberjack, and also its appropriateness for diversification with difficult marine species. © 2005 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2004

Mylonas, C C; Papadaki, M; Pavlidis, M; Divanach, P

Evaluation of egg production and quality in the Mediterranean red porgy (Pagrus pagrus) during two consecutive spawning seasons Journal Article

Aquaculture, 232 (1-4), pp. 637–649, 2004, ISSN: 00448486.

Abstract | Links | BibTeX

@article{mylonas_evaluation_2004,
title = {Evaluation of egg production and quality in the Mediterranean red porgy (Pagrus pagrus) during two consecutive spawning seasons},
author = {C C Mylonas and M Papadaki and M Pavlidis and P Divanach},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-1542321216&doi=10.1016%2fS0044-8486%2803%2900534-9&partnerID=40&md5=bb798427551c7d2bdbf2d0812cf57e45},
doi = {10.1016/S0044-8486(03)00534-9},
issn = {00448486},
year = {2004},
date = {2004-01-01},
journal = {Aquaculture},
volume = {232},
number = {1-4},
pages = {637--649},
abstract = {Egg production from two broodstocks of captive-reared red porgy (Pagrus pagrus) was monitored for two consecutive seasons (2001 and 2002). Spawning lasted from January to April-May under water temperature between 15.8 and 19.2°C. Spawning was mostly daily, though over the course of the two spawning seasons, the mean interval was 1.5-1.2 days spawn-1. There was a large variation in daily fecundity without a consistent trend, except for a slight peak in the middle of the spawning season. Mean (S.E.M.) annual relative fecundity ranged between 408,300 (95,800) and 442,500 (180,800) eggs kg-1 year-1. Mean fertilization success increased significantly from 36.9 (2.0)% in 2001 to 68.9 (2.5)% in 2002, resulting in mean annual viable egg production of 174,800 (87,600) and 301,500 (99,800) eggs kg-1, respectively. There were no significant differences between the 2 years in other egg quality parameters, which ranged between 74.5 and 79. 3% 1-day embryo survival, 81.6-85.5% hatching success and 76.7-78.8% 5-day larval survival. Of the relations examined, fertilization % had a significantly positive correlation with 1-day embryo survival, which in turn was significantly correlated with hatching %. Larval survival was further correlated with hatching %. These data suggest that decisions on whether to proceed with the incubation of a batch of eggs and rearing of the larvae can be made within 1 day from egg collection, before much effort is invested by the hatchery. The present study presents further information on the spawning kinetics, and egg production and quality characteristics of the Mediterranean red porgy in culture, and demonstrates the suitability of this species for reproduction in captivity. © 2004 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Kyriakou, Y; Sigelaki, I; Georgiou, G; Stephanou, D; Divanach, P

Reproductive biology of the shi drum (Umrina cirrosa) in captivity and induction of spawning using GNRHA Journal Article

Israeli Journal of Aquaculture - Bamidgeh, 56 (2), pp. 77–94, 2004, ISSN: 0792156X.

Abstract | Links | BibTeX

@article{mylonas_reproductive_2004,
title = {Reproductive biology of the shi drum (Umrina cirrosa) in captivity and induction of spawning using GNRHA},
author = {C C Mylonas and Y Kyriakou and I Sigelaki and G Georgiou and D Stephanou and P Divanach},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-3142760090&partnerID=40&md5=9f2ed2f2e75086d9b738a1ab4dedd38d},
issn = {0792156X},
year = {2004},
date = {2004-01-01},
journal = {Israeli Journal of Aquaculture - Bamidgeh},
volume = {56},
number = {2},
pages = {77--94},
abstract = {The reproductive biology of the shi drum (Umbrina cirrosa) in culture was histologically examined and sperm quality was monitored during an entire reproductive period. Already in April, the ovary contained oocytes in all stages of maturation, from primary oocytes to full vitellogenesis, as expected from a group-synchronous multiple-batch spawning fish. Vitellogenesis of the first batch of oocytes occurred very rapidly and their mean diameter (500 μm) did not increase significantly (p>0.05) as the reproductive period proceeded. The spermiation index peaked in May-June, but fish never produced copious amounts of milt upon abdominal pressure. The spermatozoa motility percentage remained unchanged throughout the spawning season (80%) and a significant percentage (40%) maintained viability after overnight storage at 4°C. Sperm density and motility duration increased during the reproductive period and varied 13-26 × 109 spermatozoa/ml and 26-40 s, respectively. Spontaneous spawning was not observed during the two-year study. Injection of post-vitellogenic females with an agonist of gonadotropin-releasing hormone (GnRHa) was successful in inducing a single spawning after two days, with fertilization, hatching and 4-day larval survival rates of 65%, 42-76% and 46-80%, respectively. The results underline the failure of female shi drum in culture to undergo final oocyte maturation and, although GnRHa injection was effective in inducing spawning of viable eggs, multiple treatments did not induce multiple spawns, as was expected from fish with multiple-batch group-synchronous ovarian biology.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Halm, S; Martínez-Rodríguez, G; Rodríguez, L; Prat, F; Mylonas, C C; Carrillo, M; Zanuy, S

Cloning, characterisation, and expression of three oestrogen receptors (ERα, ERβ1 and ERβ2) in the European sea bass, Dicentrarchus labrax Journal Article

Molecular and Cellular Endocrinology, 223 (1-2), pp. 63–75, 2004, ISSN: 03037207.

Abstract | Links | BibTeX

@article{halm_cloning_2004,
title = {Cloning, characterisation, and expression of three oestrogen receptors (ERα, ERβ1 and ERβ2) in the European sea bass, Dicentrarchus labrax},
author = {S Halm and G Martínez-Rodríguez and L Rodríguez and F Prat and C C Mylonas and M Carrillo and S Zanuy},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-3342941616&doi=10.1016%2fj.mce.2004.05.009&partnerID=40&md5=46ce79c38bedf1df217fcb12ab9d17c8},
doi = {10.1016/j.mce.2004.05.009},
issn = {03037207},
year = {2004},
date = {2004-01-01},
journal = {Molecular and Cellular Endocrinology},
volume = {223},
number = {1-2},
pages = {63--75},
abstract = {Three oestrogen receptor [ER] subtypes have been described in teleost fish, namely ERα, and two ERβ subtypes, called ERβ1 and ERβ2 (or ERβ and ERγ in Atlantic croaker). Their expression during embryonic development and gonadal growth has evoked interest in their potential role in sexual differentiation and gonadal development in fish. We cloned three oestrogen receptors from adult liver (sb-ERα cDNA) and ovary (partial sb-ERβ1 and sb-ERβ2 cDNAs) of the European sea bass, and according to their phylogenetic relatedness to other ERs in teleosts, named them sea bass [sb-] ERα, ERβ1 and ERβ2. Deduced amino acid numbers for sb-ERα, sb-ERβ1 and sb-ERβ2 were 639, 517 and 608, respectively, representing in the case of sb-ERβ1 and sb-ERβ2 about 90% of the open reading frame. Highest amino acid identities were found for sb-ERα with eelpout ERα (88.7%), for sb-ERβ1 with Atlantic croaker ERγ (85.8%), and for sb-ERβ2 with Atlantic croaker ERβ (90.1%). Southern analysis confirmed that all three sea bass oestrogen receptors (sb-ERs) are the products of three distinct genes. In adult sea bass, ERα was predominantly expressed in liver and pituitary, while sb-ERβ1 and sb-ERβ2 were more ubiquitously expressed, with highest expression levels in pituitary. In a mixed-sex population of juvenile sea bass, sb-ERα expression was significantly elevated in gonads at 200 days posthatch (dph), while for sb-ERβ1 and sb-ERβ2 highest expression levels were observed in gonads at 250 dph. For sb-ERβ2, expression was also significantly higher in the brain at 250 dph. The cloning of these three ER subtypes in the European sea bass together with the results obtained on expression levels in adult and juvenile animals has given us the foundation to investigate their possible role in sexual differentiation and development in this species in future studies. © 2004 Elsevier Ireland Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Papandroulakis, N; Smboukis, A; Papadaki, M; Divanach, P

Induction of spawning of cultured greater amberjack (Seriola dumerili) using GnRHa implants Journal Article

Aquaculture, 237 (1-4), pp. 141–154, 2004, ISSN: 00448486.

Abstract | Links | BibTeX

@article{mylonas_induction_2004,
title = {Induction of spawning of cultured greater amberjack (Seriola dumerili) using GnRHa implants},
author = {C C Mylonas and N Papandroulakis and A Smboukis and M Papadaki and P Divanach},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-3142566876&doi=10.1016%2fj.aquaculture.2004.04.015&partnerID=40&md5=1d5f2c1607615bf23df2ad0e72aaa783},
doi = {10.1016/j.aquaculture.2004.04.015},
issn = {00448486},
year = {2004},
date = {2004-01-01},
journal = {Aquaculture},
volume = {237},
number = {1-4},
pages = {141--154},
abstract = {The objective of the current study was to examine the possibility of maturing Mediterranean greater amberjack (Seriola dumerili) in culture at two different facilities in Greece and inducing spawning using gonadotropin releasing-hormone agonist (GnRHa) implants. Males in both stocks (n=8) were in spermiating condition in mid June, though sperm motility was low ranging between 5% and 30%, while motility duration ranged between 2.1 and 2.5 min. Females of the first stock (n=4) at the same time had ovaries with either primary oocytes or early vitellogenic oocytes at advanced stages of atresia, indicating a failure in oogenesis. On the contrary, the only female of the second stock contained oocytes at all stages of oogenesis, including early final oocyte maturation (FOM; oocyte diameter 650 μm). Implantation with a GnRHa implant induced the first spawn about 36 h later. In the absence of another spawn, a gonadal biopsy was taken 15 days later, indicating the existence of more oocytes at post vitellogenesis and some with almost complete lipid droplet coalescence. A second GnRHa implantation at this time resulted in consecutive egg releases after 36 h, 4 and 5 days, with fertilized eggs only at 36 h and 5 days. The study underlines the existence of important reproductive dysfunctions of greater amberjack in captivity, and demonstrates that GnRHa implants can be used for the induction of multiple spawns of viable eggs. © 2004 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Galay-Burgos, M; Llewellyn, L; Mylonas, C C; Canario, A V M; Zanuy, S; Sweeney, G E

Analysis of the Sox gene family in the European sea bass (Dicentrarchus labrax) Journal Article

Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology, 137 (2), pp. 279–284, 2004, ISSN: 10964959, (Publisher: Elsevier Inc.).

Abstract | Links | BibTeX

2003

Marino, G; Panini, E; Longobardi, A; Mandich, A; Finoia, M G; Zohar, Y; Mylonas, C C

Induction of ovulation in captive-reared dusky grouper, Epinephelus marginatus (Lowe, 1834), with a sustained-release GnRHa implant Journal Article

Aquaculture, 219 (1-4), pp. 841–858, 2003, ISSN: 00448486, (Publisher: Elsevier).

Abstract | Links | BibTeX

Rainis, S; Mylonas, C C; Kyriakou, Y; Divanach, P

Enhancement of spermiation in European sea bass (Dicentrarchus labrax) at the end of the reproductive season using GnRHa implants Journal Article

Aquaculture, 219 (1-4), pp. 873–890, 2003, ISSN: 00448486, (Publisher: Elsevier).

Abstract | Links | BibTeX

@article{rainis_enhancement_2003,
title = {Enhancement of spermiation in European sea bass (Dicentrarchus labrax) at the end of the reproductive season using GnRHa implants},
author = {S Rainis and C C Mylonas and Y Kyriakou and P Divanach},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037414059&doi=10.1016%2fS0044-8486%2803%2900028-0&partnerID=40&md5=1ef1061621cd17c6bab8bac850349250},
doi = {10.1016/S0044-8486(03)00028-0},
issn = {00448486},
year = {2003},
date = {2003-01-01},
journal = {Aquaculture},
volume = {219},
number = {1-4},
pages = {873--890},
abstract = {Spermiating European sea bass (Dicentrarchus labrax) were treated at the end of the reproductive period (22 February 2002) with implants of gonadotropin-releasing hormone agonist (GnRHa), in order to examine their potential in enhancing expressible milt volume, sperm quality and in vitro fertilization success. The GnRHa implants at all doses (20, 40 and 80 μg GnRHa kg-1 body weight [bw]) stimulated a significantly higher production of milt compared to controls over a 27-day period, increasing total volume from 0.5 to 2.2 ml kg-1 sample time-1. No differences in milt production were observed among the three GnRHa doses. Histological evaluation of the testes indicated that, by day 21, control fish had entered into gonadal regression, containing almost exclusively spermatogonia. At the same time, testes from GnRHa-implanted fish still contained large numbers of spermatozoa in the testes, indicating that spermiation was still underway. Sperm density varied between 7.4 and 14.4 × 1010 spermatozoa ml-1, but remained unchanged in response to GnRHa implantation. Sperm motility was high at the beginning of the experiment (92-100%) and decreased significantly by day 27 (32-55%), whereas motility duration was unchanged (0.9-1.2 min). Neither sperm motility nor motility duration was affected by the GnRHa treatment. Finally, fertilization success was high (40-80%) and not significantly different in response to GnRHa implantation. These results demonstrate that GnRHa implants are effective at increasing milt production at the end of the spermiation period, maintaining high sperm density and not affecting, either positively or negatively, sperm quality and fertilization capacity. © 2003 Elsevier Science B.V. All rights reserved.},
note = {Publisher: Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Papadaki, M; Divanach, P

Seasonal changes in sperm production and quality in the red porgy Pagrus pagrus (L.) Journal Article

Aquaculture Research, 34 (13), pp. 1161–1170, 2003, ISSN: 1355557X.

Abstract | Links | BibTeX

Mylonas, C C; Sigelaki, I; Divanach, P; Mananõs, E; Carrillo, M; Afonso-Polyviou, A

Multiple spawning and egg quality of individual European sea bass (Dicentrarchus labrax) females after repeated injections of GnRHa Journal Article

Aquaculture, 221 (1-4), pp. 605–620, 2003, ISSN: 00448486, (Publisher: Elsevier).

Abstract | Links | BibTeX

@article{mylonas_multiple_2003,
title = {Multiple spawning and egg quality of individual European sea bass (Dicentrarchus labrax) females after repeated injections of GnRHa},
author = {C C Mylonas and I Sigelaki and P Divanach and E Mananõs and M Carrillo and A Afonso-Polyviou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037402489&doi=10.1016%2fS0044-8486%2803%2900120-0&partnerID=40&md5=4fa3ca75d178e099a929643bd3f005cd},
doi = {10.1016/S0044-8486(03)00120-0},
issn = {00448486},
year = {2003},
date = {2003-01-01},
journal = {Aquaculture},
volume = {221},
number = {1-4},
pages = {605--620},
abstract = {Using multiple injections of gonadotropin-releasing hormone agonist (GnRHa) (10 μg kg-1 bw) spaced 7-14 days apart, we investigated the multiple-batch group-synchronous spawning kinetics of individual European sea bass females (n = 6) and examined batch fecundity and egg quality parameters. Spawning was obtained 3-4 days after each GnRHa injection. A mean of 2.8 spawns female-1 was obtained, with a minimum of 2 and maximum of 4. Mean relative fecundity of the first spawn was 320,211 eggs kg-1 bw and decreased continuously in subsequent spawns, reaching 52,381 eggs kg-1. Total mean relative fecundity for all spawns was 637,900 eggs kg-1. Mean fertilization success did not vary significantly among sequential spawns and ranged between 67% and 91%. On the contrary, there were significant differences among the four spawns in embryo survival 1 day after egg collection, hatching percentage and larval survival 4 days after egg collection, but there was no consistent trend during the study. Significant positive correlations existed between 4-day larval survival and hatching percentage (P=0.0002), and between hatching percentage and embryo survival 1 day after egg collection (P=0.03), indicating that 1-day embryo survival can be a potential biomarker for egg quality in commercial hatcheries. The results of the study demonstrate that European sea bass can produce up to four sequential spawns of high quality eggs in response to repeated acute treatments of GnRHa, and suggest that a pulsatile treatment of GnRHa may be necessary to induce the appropriate cycles of hormone changes for the recruitment, maturation and ovulation of multiple batches of viable eggs. © 2003 Elsevier Science B.V. All rights reserved.},
note = {Publisher: Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Anezaki, L; Divanach, P; Zanuy, S; Piferrer, F; Ron, B; Peduel, A; Atia, Ben I; Gorshkov, S; Tandler, A

Influence of rearing temperature at two periods during early life on growth and sex differentiation of two strains of European sea bass Journal Article

Fish Physiology and Biochemistry, 28 (1-4), pp. 167–168, 2003, ISSN: 09201742.

Abstract | Links | BibTeX

Rodríguez, L; Halm, S; Mylonas, C; Zanuy, S

Gene expression of estrogen receptors α and β during early sexual differentiation in the European sea bass (Dicentrarchus labrax) Journal Article

Fish Physiology and Biochemistry, 28 (1-4), pp. 175, 2003, ISSN: 09201742.

Abstract | Links | BibTeX

2002

Mañanós, E; Carrillo, M; Sorbera, L A; Mylonas, C C; Asturiano, J F; Bayarri, M J; Zohar, Y; Zanuy, S

Luteinizing hormone and sexual steroid plasma levels after treatment of European sea bass with sustained-release delivery systems for gonadotropin-releasing hormone analogue Journal Article

Journal of Fish Biology, 60 (2), pp. 328–339, 2002, ISSN: 00221112.

Abstract | Links | BibTeX

@article{mananos_luteinizing_2002,
title = {Luteinizing hormone and sexual steroid plasma levels after treatment of European sea bass with sustained-release delivery systems for gonadotropin-releasing hormone analogue},
author = {E Mañanós and M Carrillo and L A Sorbera and C C Mylonas and J F Asturiano and M J Bayarri and Y Zohar and S Zanuy},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036464151&doi=10.1006%2fjfbi.2001.1839&partnerID=40&md5=6f51e3fd5612a507457f3a7cfecdc891},
doi = {10.1006/jfbi.2001.1839},
issn = {00221112},
year = {2002},
date = {2002-01-01},
journal = {Journal of Fish Biology},
volume = {60},
number = {2},
pages = {328--339},
abstract = {Spermiating male European sea bass Dicentrarchus labrax were treated with gonadotropin-releasing hormone agonists (GnRHa), either a GnRHa injection (IN; 25 μg kg-1 body mass) or one of three types of controlled-release GnRHa-delivery systems: fast release implants (EVAc; 100 μg kg-1), slow release implants (EVSL; 100 μg kg-1) and slow release microspheres (MC; 50 μg kg-1). Luteinizing hormone (LH) release was highly stimulated by all GnRHa treatments, with elevated plasma levels lasting for 2 days in injected fish (IN) and 2, 4 and 6 weeks in controlled-release-treated fish (EVAc, MC and EVSL, respectively), correlating with a 1, 3, 5 and 5 week period of stimulation of milt production, respectively. Plasma levels of the androgens testosterone (T) and 11-ketotestosterone (11-KT), were not significantly affected by the GnRHa treatments. Plasma T was high at early spermiation and declined sharply near the end of this period. Plasma 11-KT levels declined continuously throughout the experiment. Levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P), a proposed maturation-inducing steroid (MIS) in European sea bass, fluctuated around 0.2-1 ng ml-1 and were not greatly affected by the treatments. These results indicated a close correlation between sustained stimulation of LH release, achieved by GnRHa-delivery systems, and long-term enhancement of milt production. They also show an absence of changes in the common sex steroids, associated with elevated LH and enhanced spermiation. © 2002 The Fisheries Society of the British Isles.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

2001

Greenwood, L N; Scott, A P; Vermeirssen, E L M; Mylonas, C C; Pavlidis, M

Plasma steroids in mature common dentex (Dentex dentex) stimulated with a gonadotropin-releasing hormone agonist Journal Article

General and Comparative Endocrinology, 123 (1), pp. 1–12, 2001, ISSN: 00166480.

Abstract | Links | BibTeX

@article{greenwood_plasma_2001,
title = {Plasma steroids in mature common dentex (Dentex dentex) stimulated with a gonadotropin-releasing hormone agonist},
author = {L N Greenwood and A P Scott and E L M Vermeirssen and C C Mylonas and M Pavlidis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034944955&doi=10.1006%2fgcen.2000.7519&partnerID=40&md5=a67970e64ad41e8b9ec71482ff619e51},
doi = {10.1006/gcen.2000.7519},
issn = {00166480},
year = {2001},
date = {2001-01-01},
journal = {General and Comparative Endocrinology},
volume = {123},
number = {1},
pages = {1--12},
abstract = {The aim of this study was to identify the major C21 steroids produced in vivo during artificially induced final oocyte maturation and spawning in female common dentex (Dentex dentex). During the spawning season, mature females were treated with a gonadotropin-releasing hormone agonist (GnRHa)-loaded delivery system, with or without pimozide (given as a single dose at the beginning of the experiment). Blood samples were collected at various intervals during the experiment and were assayed for GnRHa, 17, 20β-dihydroxy-4-pregnen-3-one (17, 20β-P), and 17, 20β, 21-trihydroxy-4-pregnen-3-one (17, 20β, 21-P). A higher percentage of ovulated females was observed in GnRHa-implanted fish, which produced over 10 times more eggs than controls. Relative fecundity was highest in the GnRHa + pimozide group and lowest in controls. The viability of naturally released eggs was low (2 to 15%) in all groups. Plasma concentrations of 17, 20β-P in GnRHa-implanted fish did not increase, but those in control fish decreased, such that there was a significant difference between control and treated fish between 2 and 10 days after treatment. In another experiment, ovulating common dentex were injected intramuscularly with a single dose of 50 μg kg−1 of GnRHa in saline and were sampled for blood at 0, 3, 6, 12, and 24 h postinjection. A single water sample was taken from the tanks at 9 h postinjection, the tanks having been emptied and refilled at 6 h. Measurements were made of plasma and water concentrations of free and conjugated 17, 20β-P, 17, 20β, 21-P, 17β-oestradiol (E2), and GnRHa (plasma only). The GnRHa injection increased plasma levels of all steroids, with free 17, 20β-P reaching maximal levels within 3 h. GnRHa treatment also increased the amounts of free and conjugated steroids released into the water between 6 and 9 h. © 2001 British Crown.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Zohar, Y; Mylonas, C C

Endocrine manipulations of spawning in cultured fish: From hormones to genes Journal Article

Aquaculture, 197 (1-4), pp. 99–136, 2001, ISSN: 00448486.

Abstract | Links | BibTeX

@article{zohar_endocrine_2001,
title = {Endocrine manipulations of spawning in cultured fish: From hormones to genes},
author = {Y Zohar and C C Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035371765&doi=10.1016%2fS0044-8486%2801%2900584-1&partnerID=40&md5=a0f675c73f277d13cecaf3b092505c8c},
doi = {10.1016/S0044-8486(01)00584-1},
issn = {00448486},
year = {2001},
date = {2001-01-01},
journal = {Aquaculture},
volume = {197},
number = {1-4},
pages = {99--136},
abstract = {Almost all fish reared in captivity exhibit some form of reproductive dysfunction. In females, there is often failure to undergo final oocyte maturation, ovulation and spawning; while in males milt production may be reduced and of low quality. These dysfunctions are due to the fact that fish in captivity do not experience the conditions of the spawning grounds, and as a result there is a failure of the pituitary to release the maturational gonadotropin, luteinizing hormone (LH). Reproductive hormones have been utilized since the 1930s to stimulate reproductive processes and induce ovulation/spermiation and spawning. The first methods employed freshly ground pituitaries collected from reproductively mature fish, which contained gonadotropins (mainly LH) and induced steroidogenesis and gonadal maturation. Eventually, purified gonadotropins became available, both of piscine and mammalian origin, e.g., carp or salmon gonadotropin, and human chorionic gonadotropin. In the 1970s, spawning induction methods begun employing the newly discovered gonadotropin-releasing hormone (GnRH), which induces the secretion of the fish's own gonadotropin from the pituitary, thereby overcoming the endocrine failure observed in captive broodstocks. Development of highly potent, synthetic agonists of GnRH (GnRHa) constituted the next generation of hormonal manipulation therapies, and created a surge in the use of hormones to control reproductive processes in aquaculture. The most recent development is the incorporation of GnRHa into polymeric sustained-release delivery systems, which release the hormone over a period of days to weeks. These delivery systems alleviate the need for multiple treatments and induce (a) long-term elevation in sperm production and (b) multiple spawning in fish with asynchronous or multiple-batch group-synchronous ovarian physiology. Based on the recent discovery of GnRH multiplicity in fish and the increasing understanding of its functional significance, new GnRH agonists can be designed for more potent, affordable and physiologically-compatible spawning induction therapies. Future strategies for improved spawning manipulations will be based on understanding the captivity-induced alterations in the GnRH system, and on new approaches for their repair at the level of GnRH gene expression and release. © 2001 Elsevier Science B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Almost all fish reared in captivity exhibit some form of reproductive dysfunction. In females, there is often failure to undergo final oocyte maturation, ovulation and spawning; while in males milt production may be reduced and of low quality. These dysfunctions are due to the fact that fish in captivity do not experience the conditions of the spawning grounds, and as a result there is a failure of the pituitary to release the maturational gonadotropin, luteinizing hormone (LH). Reproductive hormones have been utilized since the 1930s to stimulate reproductive processes and induce ovulation/spermiation and spawning. The first methods employed freshly ground pituitaries collected from reproductively mature fish, which contained gonadotropins (mainly LH) and induced steroidogenesis and gonadal maturation. Eventually, purified gonadotropins became available, both of piscine and mammalian origin, e.g., carp or salmon gonadotropin, and human chorionic gonadotropin. In the 1970s, spawning induction methods begun employing the newly discovered gonadotropin-releasing hormone (GnRH), which induces the secretion of the fish's own gonadotropin from the pituitary, thereby overcoming the endocrine failure observed in captive broodstocks. Development of highly potent, synthetic agonists of GnRH (GnRHa) constituted the next generation of hormonal manipulation therapies, and created a surge in the use of hormones to control reproductive processes in aquaculture. The most recent development is the incorporation of GnRHa into polymeric sustained-release delivery systems, which release the hormone over a period of days to weeks. These delivery systems alleviate the need for multiple treatments and induce (a) long-term elevation in sperm production and (b) multiple spawning in fish with asynchronous or multiple-batch group-synchronous ovarian physiology. Based on the recent discovery of GnRH multiplicity in fish and the increasing understanding of its functional significance, new GnRH agonists can be designed for more potent, affordable and physiologically-compatible spawning induction therapies. Future strategies for improved spawning manipulations will be based on understanding the captivity-induced alterations in the GnRH system, and on new approaches for their repair at the level of GnRH gene expression and release. © 2001 Elsevier Science B.V.

Forniés, M A; Mañanós, E; Carrillo, M; Rocha, A; Laureau, S; Mylonas, C C; Zohar, Y; Zanuy, S

Spawning induction of individual European sea bass females (Dicentrarchus labrax) using different GnRHa-delivery systems Journal Article

Aquaculture, 202 (3-4), pp. 221–234, 2001, ISSN: 00448486, (Publisher: Elsevier).

Abstract | Links | BibTeX

@article{fornies_spawning_2001,
title = {Spawning induction of individual European sea bass females (Dicentrarchus labrax) using different GnRHa-delivery systems},
author = {M A Forniés and E Mañanós and M Carrillo and A Rocha and S Laureau and C C Mylonas and Y Zohar and S Zanuy},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035509922&doi=10.1016%2fS0044-8486%2801%2900773-6&partnerID=40&md5=9b233b084d0915f643c35513f1180854},
doi = {10.1016/S0044-8486(01)00773-6},
issn = {00448486},
year = {2001},
date = {2001-01-01},
journal = {Aquaculture},
volume = {202},
number = {3-4},
pages = {221--234},
abstract = {The present study evaluated the effect of different delivery systems loaded with gonadotropin-releasing hormone agonist (GnRHa) on spawning induction, and egg and larval quality in female European sea bass (Dicentrarchus labrax). Mature females (mean ± S.E.M. oocyte diameter = 905 ± 10 μm) were treated with [D-Ala6, Pro9 NEt]-mGnRHa using GnRHa-loaded microspheres, Mc (60 μg kg-1 body weight, bw) GnRHa-loaded implants, EVAc (50 μg kg-1 bw) or received a single injection of GnRHa in saline, IN (15 μg kg-1 bw). Controls (C) were injected with saline. Females were allocated individually in 2-m3 tanks with two GnRHa-treated males and were allowed to spawn without further handling. All GnRHa treatments induced spawning 3 days after treatment (d.a.t.), whereas control fish did not spawn during the 21-day experimental period. GnRHa microspheres and implants induced up to four consecutive spawns in one female, whereas GnRHa-injected fish spawned only once. Egg quality seemed relatively lower in all GnRHa-treated groups compared to spontaneously spawning fish (natural spawns, NAT group) maintained in large populations (80 fish in 15-m3 tanks), possibly due to both the isolation of individual females in separate tanks and the stress from handling. Mean egg quality of the first spawns was variable, but similar in all GnRHa treatments (6.6-18.2% buoyancy; 21.7-27.4% hatching). In subsequent spawns, the Mc-treated females produced eggs of higher buoyancy than the EVAc group (20.5 ± 6.0% vs. 2.87 ± 1.14%), and similar to the first spawn of the GnRHa-injected group. Our results indicate that, compared to a single GnRHa injection, GnRHa-loaded microspheres can induce multiple spawns in European sea bass, without a negative effect on egg quality. © 2001 Elsevier Science B.V. All rights reserved.},
note = {Publisher: Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Zohar, Y

Endocrine regulation and artificial induction of oocyte maturation and spermiation in basses of the genus Morone Journal Article

Aquaculture, 202 (3-4), pp. 205–220, 2001, ISSN: 00448486.

Abstract | Links | BibTeX

@article{mylonas_endocrine_2001,
title = {Endocrine regulation and artificial induction of oocyte maturation and spermiation in basses of the genus Morone},
author = {C C Mylonas and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035510250&doi=10.1016%2fS0044-8486%2801%2900772-4&partnerID=40&md5=234515ff5965a8f17502acba9688f431},
doi = {10.1016/S0044-8486(01)00772-4},
issn = {00448486},
year = {2001},
date = {2001-01-01},
journal = {Aquaculture},
volume = {202},
number = {3-4},
pages = {205--220},
abstract = {Studying the process of final oocyte maturation (FOM) and spermiation in striped bass (Morone saxatilis), it was determined that the failure to undergo FOM and produce normal amounts of milt in captivity was due to low plasma levels of luteinizing hormone (LH) during the spawning period. As a result, the expected changes in the plasma profiles of the steroids involved in FOM and spermiation do not take place. Based on the hormone profiles and the associated histological examinations, FOM can be separated into an early phase (germinal vesicle (gv) migration) and a late phase (germinal vesicle breakdown). The progestogen 17,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P) was identified as the maturation-inducing steroid (MIS), but the high levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) present during late FOM, suggest a role for this steroid also. In wild striped bass, spermiation was associated with increases in LH and unchanged plasma levels of 17,20β,21-P and 17, 20β-P. In culture, spermiation in both striped bass and white bass (M. chrysops) proceeds under undetectable levels of LH, 17,20β,21-P and 17,20β-P. GnRHa-induced spermiation, however, was associated with increases in plasma LH and 17,20β-P, but not 17,20β,21-P. Treatment of females with GnRHa-delivery systems induced long-term increases in plasma LH and the appropriate changes in sex-steroid hormones. In white bass, GnRHa-delivery systems induced two successive spawns within 3 days from treatment, and in a commercial production facility induced ovulation of 90% of the females, producing 294,500 eggs kg-1 with 81% fertilization. Similarly treated striped bass underwent FOM and ovulation within 10 days after treatment, while tank spawning resulted in the production of 170,000 eggs kg-1 with 47% fertilization success. In male fish, GnRHa-delivery systems induced significant elevations of expressible milt for up to 20 days, resulting in a fourfold increase in production of spermatozoa, without affecting sperm density, motility or fertilization %. © 2001 Published by Elsevier Science B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Studying the process of final oocyte maturation (FOM) and spermiation in striped bass (Morone saxatilis), it was determined that the failure to undergo FOM and produce normal amounts of milt in captivity was due to low plasma levels of luteinizing hormone (LH) during the spawning period. As a result, the expected changes in the plasma profiles of the steroids involved in FOM and spermiation do not take place. Based on the hormone profiles and the associated histological examinations, FOM can be separated into an early phase (germinal vesicle (gv) migration) and a late phase (germinal vesicle breakdown). The progestogen 17,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P) was identified as the maturation-inducing steroid (MIS), but the high levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) present during late FOM, suggest a role for this steroid also. In wild striped bass, spermiation was associated with increases in LH and unchanged plasma levels of 17,20β,21-P and 17, 20β-P. In culture, spermiation in both striped bass and white bass (M. chrysops) proceeds under undetectable levels of LH, 17,20β,21-P and 17,20β-P. GnRHa-induced spermiation, however, was associated with increases in plasma LH and 17,20β-P, but not 17,20β,21-P. Treatment of females with GnRHa-delivery systems induced long-term increases in plasma LH and the appropriate changes in sex-steroid hormones. In white bass, GnRHa-delivery systems induced two successive spawns within 3 days from treatment, and in a commercial production facility induced ovulation of 90% of the females, producing 294,500 eggs kg-1 with 81% fertilization. Similarly treated striped bass underwent FOM and ovulation within 10 days after treatment, while tank spawning resulted in the production of 170,000 eggs kg-1 with 47% fertilization success. In male fish, GnRHa-delivery systems induced significant elevations of expressible milt for up to 20 days, resulting in a fourfold increase in production of spermatozoa, without affecting sperm density, motility or fertilization %. © 2001 Published by Elsevier Science B.V.

Panini, E B; Mylonas, C C; Zanuy, S; Carrillo, M; Ramos, J; Bruce, M P

Incubation of embryos and larvae of marine fish using microtiter plates Journal Article

Aquaculture International, 9 (2), pp. 189–195, 2001, ISSN: 09676120.

Links | BibTeX

2000

Mylonas, C C; Zohar, Y

Use of GnRHa-delivery systems for the control of reproduction in fish Journal Article

Reviews in Fish Biology and Fisheries, 10 (4), pp. 463–491, 2000, ISSN: 09603166.

Abstract | Links | BibTeX

@article{mylonas_use_2000,
title = {Use of GnRHa-delivery systems for the control of reproduction in fish},
author = {C C Mylonas and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034528406&doi=10.1023%2fA%3a1012279814708&partnerID=40&md5=93dc83bb17d6f49997555b7c15c0bd30},
doi = {10.1023/A:1012279814708},
issn = {09603166},
year = {2000},
date = {2000-01-01},
journal = {Reviews in Fish Biology and Fisheries},
volume = {10},
number = {4},
pages = {463--491},
abstract = {The most commonly observed reproductive dysfunctions in cultured fish are the unpredictability of final oocyte maturation (FOM) in females, and the diminished volume and quality of sperm in males. Gonadotropin-releasing hormone agonists (GnRHa) have been used extensively in order to stimulate the release of pituitary luteinizing hormone (LH) required to induce FOM, ovulation and spermiation. Because multiple hormonal treatments are often necessary for a successful response, fish must be monitored and handled extensively, which is labor intensive, stressful to the fish and can often result in broodstock mortalities. To ameliorate this problem, sustained-release delivery systems for GnRHa have been developed during the last two decades and have been increasingly applied in controlling reproduction of a variety of cultured fish. Solid implants of cholesterol or poly[ethylene-vinyl acetate], and biodegradable microspheres of poly[lactide-glycolide] or poly[fatty acid dimer-sebasic acid] release GnRHa for a period of time (from a few days to many weeks.) GnRHa-delivery systems do not cause desensitization of the pituitary gonadotrophs in fish, and by stimulating a sustained elevation of plasma LH they induce the natural progression of plasma steroid increases associated with FOM and spermiation. This method has been used with very encouraging results in females of more than 40 cultured species and has been effective in inducing FOM, ovulation or spawning in fish with synchronous, group-synchronous and asynchronous ovarian development. In males, GnRHa-delivery systems have been tested in more than 20 species, producing significant increases in milt production for up to 5 weeks. Future research should focus on the optimization of this technology in terms of (a) using the most potent GnRHa, (b) identifying the most appropriate GnRHa release kinetics according to the reproductive biology of different species, and (c) determining minimum effective doses. Developments in these areas will greatly enhance the effectiveness and efficiency of GnRHa-delivery systems, while at the same time reducing their cost thus making them more affordable to the aquaculture industry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The most commonly observed reproductive dysfunctions in cultured fish are the unpredictability of final oocyte maturation (FOM) in females, and the diminished volume and quality of sperm in males. Gonadotropin-releasing hormone agonists (GnRHa) have been used extensively in order to stimulate the release of pituitary luteinizing hormone (LH) required to induce FOM, ovulation and spermiation. Because multiple hormonal treatments are often necessary for a successful response, fish must be monitored and handled extensively, which is labor intensive, stressful to the fish and can often result in broodstock mortalities. To ameliorate this problem, sustained-release delivery systems for GnRHa have been developed during the last two decades and have been increasingly applied in controlling reproduction of a variety of cultured fish. Solid implants of cholesterol or poly[ethylene-vinyl acetate], and biodegradable microspheres of poly[lactide-glycolide] or poly[fatty acid dimer-sebasic acid] release GnRHa for a period of time (from a few days to many weeks.) GnRHa-delivery systems do not cause desensitization of the pituitary gonadotrophs in fish, and by stimulating a sustained elevation of plasma LH they induce the natural progression of plasma steroid increases associated with FOM and spermiation. This method has been used with very encouraging results in females of more than 40 cultured species and has been effective in inducing FOM, ovulation or spawning in fish with synchronous, group-synchronous and asynchronous ovarian development. In males, GnRHa-delivery systems have been tested in more than 20 species, producing significant increases in milt production for up to 5 weeks. Future research should focus on the optimization of this technology in terms of (a) using the most potent GnRHa, (b) identifying the most appropriate GnRHa release kinetics according to the reproductive biology of different species, and (c) determining minimum effective doses. Developments in these areas will greatly enhance the effectiveness and efficiency of GnRHa-delivery systems, while at the same time reducing their cost thus making them more affordable to the aquaculture industry.

1998

Vermeirssen, E L M; Scott, A P; Mylonas, C C; Zohar, Y

Gonadotrophin-releasing hormone agonist stimulates milt fluidity and plasma concentrations of 17,20β-dihydroxylated and 5β-reduced, 3α- hydroxylated C21 steroids in male plaice (Pleuronectes platessa) Journal Article

General and Comparative Endocrinology, 112 (2), pp. 163–177, 1998, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{vermeirssen_gonadotrophin-releasing_1998,
title = {Gonadotrophin-releasing hormone agonist stimulates milt fluidity and plasma concentrations of 17,20β-dihydroxylated and 5β-reduced, 3α- hydroxylated C21 steroids in male plaice (Pleuronectes platessa)},
author = {E L M Vermeirssen and A P Scott and C C Mylonas and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031791147&doi=10.1006%2fgcen.1998.7132&partnerID=40&md5=084f5de31828689e1bc39bc6cff252d6},
doi = {10.1006/gcen.1998.7132},
issn = {00166480},
year = {1998},
date = {1998-01-01},
journal = {General and Comparative Endocrinology},
volume = {112},
number = {2},
pages = {163--177},
abstract = {Spermiating male plaice were caught in the North Sea and acclimatised to laboratory conditions. In two experiments, males were injected intramuscularly with either microspheres or pellets containing gonadotrophin- releasing hormone agonist (GnRHa). Blood was sampled at 2- to 5-day intervals. Individual blood plasma specimens were assayed for testosterone, 5β-reduced, 3α-hydroxy ('5β,3α') steroids and sulphated 17,20βdihydroxy ('17,20β') steroids. Pooled plasma samples were also assayed for free and sulphated 17,20β-dihydroxy-4-pregnen-3-one, free 11-ketotestosterone, and glucuronidated testosterone and 11-ketotestosterone. Plasma concentrations of all steroids were significantly elevated by GnRHa from 2 to 5 days onwards following treatment. The most marked changes occurred in the concentrations of the sulphated 17,20β steroids, which comprised approximately equal amounts of 5β-pregnane-3α, 17,20β-triol 20-sulphate (3α,17,20β-P-5β-S) and 5β-pregnane-3β,17,20β-triol 20-sulphate, rising from ca. 1 to 30-80 ng/ml in the first and from ca. 8 to 80 ng/ml in the second experiment. Concentrations of 511,3α steroids matched those of 17,20β steroids in one experiment. However, in the other experiment, the two RIAs yielded highly disparate results in about 50% of the fish (including males in the control group). The plasma of these fish contained excessive amounts of 5β,3α- immunoreactive material between 10 and 25 days. This material was identified as 3α,17,21-trihydroxy-5β-pregnan-20-one 21-sulphate (a metabolite of 11- deoxycortisol). All previous studies have indicated that when plasma concentrations of this steroid are high, so are those of 3α,17,20β-P-5β- S. This is the first indication that these steroids are regulated independently. In a third experiment, milt fluidity and production were assessed at 10, 15, and 25 days following GnRHa implantation. Milt volume and fluidity were significantly enhanced by the GnRHa treatment.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Zohar, Y; III, Woods L C; Thomas, P; Schulz, R W

Hormone profiles of captive striped bass Morone saxatilis during spermiation, and long-term enhancement of milt production Journal Article

Journal of the World Aquaculture Society, 29 (4), pp. 379–392, 1998, ISSN: 08938849, (Publisher: World Aquaculture Society).

Abstract | Links | BibTeX

@article{mylonas_hormone_1998,
title = {Hormone profiles of captive striped bass Morone saxatilis during spermiation, and long-term enhancement of milt production},
author = {C C Mylonas and Y Zohar and L C Woods III and P Thomas and R W Schulz},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032261401&doi=10.1111%2fj.1749-7345.1998.tb00662.x&partnerID=40&md5=d718fea93ab4b8da4e8fb81c44a88e58},
doi = {10.1111/j.1749-7345.1998.tb00662.x},
issn = {08938849},
year = {1998},
date = {1998-01-01},
journal = {Journal of the World Aquaculture Society},
volume = {29},
number = {4},
pages = {379--392},
abstract = {Plasma profiles of reproductive and thyroid hormones were studied in captive striped bass Morone saxatilis during an 11-wk period encompassing the spawning season, and the effect of a sustained-release gonadotropin-releasing hormone agonist (GnRHa)-delivery system (GnRHa-implant) on milt production was evaluated. The highest percentage of spermiating fish was observed between mid-April and mid-May, and mean total expressible milt ranged from 3.5 to 6.0 mL/kg. Plasma gonadotropin II (GtH II) increased significantly, though inconsistently, during the spermiation period, whereas testosterone and 11-ketotestosterone levels declined continually. Plasma 17,20β-dihydroxy-4-pregnen-3-one and 17,20β,21-dihydroxy-4-pregnen-3-one remained low and unchanged during the peak of the spermiation period, while thyroid hormones were high and fluctuated without exhibiting a trend consistent with spermiation. The observed endocrine profiles suggest that captivity can diminish plasma GtH II and triiodothyronine levels in striped bass. Transfer of spermiating males from large holding tanks to small spawning tanks reduced total expressible milt after 14 d, but treatment with a GnRHa-implant restored milt volume, presumably due to the prolonged elevation of plasma GnRHa and GtH II induced by the GnRHa-implant. Also, treatment with the GnRHa-implant induced a two-to four-fold elevation of expressible milt for at least 20 d compared to control fish, while resulting in only a 5 to 15% decrease in sperm density. It appears that captivity and hatchery operations can diminish milt production in striped bass, and that GnRHa-delivery systems, via sustained elevation of plasma GtH II, can induce long-term enhancement in milt volume without affecting sperm density greatly.},
note = {Publisher: World Aquaculture Society},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; III, Woods L C; Thomas, P; Zohar, Y

Endocrine profiles of female-striped bass (Morone saxatilis) in captivity, during postvitellogenesis and induction of final oocyte maturation via controlled-release GnRHa-delivery systems Journal Article

General and Comparative Endocrinology, 110 (3), pp. 276–289, 1998, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{mylonas_endocrine_1998,
title = {Endocrine profiles of female-striped bass (Morone saxatilis) in captivity, during postvitellogenesis and induction of final oocyte maturation via controlled-release GnRHa-delivery systems},
author = {C C Mylonas and L C Woods III and P Thomas and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031840295&doi=10.1006%2fgcen.1998.7073&partnerID=40&md5=c7317f6fe3df89e568e9b512562853c4},
doi = {10.1006/gcen.1998.7073},
issn = {00166480},
year = {1998},
date = {1998-01-01},
journal = {General and Comparative Endocrinology},
volume = {110},
number = {3},
pages = {276--289},
abstract = {Plasma levels of reproductive and thyroid hormones were measured in captive striped bass females during postvitellogenesis and the spawning period (March-June). Circulating gonadotropin II (GtH II), 17,20β-dihydroxy- 4-pregnen-3-one (17,20β-P), and 17,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P) remained low and unchanged in nonmaturing females, while 17β- estradiol (E2) and testosterone (T) declined throughout postvitellogenesis. Plasma thyroxine (T4) declined significantly in mid-April, while triiodothyronine (T3) increased in mid-May. The only female that ovulated spontaneously had markedly different E2, T, and T3 profiles during postvitellogenesis, and had a surge in plasma GtH II during final oocyte maturation (FOM). The lack of a GtH II surge is presumably responsible for the absence of FOM, but earlier, and as of yet unknown, endocrine disruptions during postvitellogenesis may determine the female's ability to undergo FOM. Treatment of females with a gonadotropin-releasing hormone agonist (GnRHa)- delivery system induced FOM and ovulation within 3 and 10 days, respectively, and resulted in the production of fertile eggs. Plasma GtH II increased continually after GnRHa implantation, even in the presence of declining GnRHa plasma levels. Plasma E2 increased first and peaked prior to FOM, whereas T peaked at the peripheral germinal vesicle (GV) stage. Plasma 17,20β-P and 17,20β,21-P increased dramatically at the GV breakdown (GVBD) stage. Plasma T4 was unaffected by the GnRHa treatment, whereas T3 decreased after GnRHa implantation and remained low throughout FOM. Based on the observed hormonal profiles, FOM can be separated into an early phase (lipid-droplet coalescence, GV migration) associated with E2 and T elevations, and a late phase (yolk-globule coalescence, GVBD) associated with 17,20β-P and 17,20β,21-P elevation.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

1997

Mylonas, C C; Scott, A P; Zohar, Y

Plasma gonadotropin II, sex steroids, and thyroid hormones in wild striped bass (Morone saxatilis) during spermiation and final oocyte maturation Journal Article

General and Comparative Endocrinology, 108 (2), pp. 223–236, 1997, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{mylonas_plasma_1997,
title = {Plasma gonadotropin II, sex steroids, and thyroid hormones in wild striped bass (Morone saxatilis) during spermiation and final oocyte maturation},
author = {C C Mylonas and A P Scott and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030728062&doi=10.1006%2fgcen.1997.6967&partnerID=40&md5=e2e788f3e08d9b279b44c1e17b96812f},
doi = {10.1006/gcen.1997.6967},
issn = {00166480},
year = {1997},
date = {1997-01-01},
journal = {General and Comparative Endocrinology},
volume = {108},
number = {2},
pages = {223--236},
abstract = {The blood levels of gonadotropin II (GtH II), sex-steroid hormones, and thyroid hormones were determined in wild spermiating male striped bass (Morone saxatilis) in males and in females at various stages of final oocyte maturation (FOM), captured on their spawning grounds. The progression of spermiation was associated with increases in plasma GtH II and decreases in plasma testosterone (T), 11-ketotestosterone, and thyroxine (T4). Plasma triiodothyronine (T3) remained at high and relatively unchanged levels. Plasma levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) and 17,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P), the proposed maturation-inducing steroids (MIS) in striped bass, were low and unchanged during the same period. It was concluded that low progestogen levels are adequate to induce spermiation in striped bass, and that higher levels may be associated with spawning behavior. In the females, based on the profiles of the studied hormones, FOM was separated into two phases. Early FOM, which included germinal vesicle (GV) migration and lipid-droplet coalescence, was associated with elevations in plasma GtH II, T, and estradiol 17β. Late FOM, which included GV breakdown and yolk-globule coalescence, was associated with a further surge in plasma GtH II, increases in the levels of the two MIS, mainly 17,20β-P, and a drop in T4. Plasma T3 levels did not change during FOM. Examination of conjugated steroids demonstrated, in the males, a reduction in conjugated androgens at the peak of the spawning season and, in the females, a small increase in conjugated 17,20β-dihydroxylated and 5β- reduced, 3α-hydroxylated steroids after spawning. This is the most comprehensive report, to date, on the endocrine regulation of gonadal maturation in wild striped bass, demonstrating that a two-stage process of FOM is regulated by different endocrine signals, providing further evidence for the involvement of 17,20β-P as a MIS in the females, and indicating that both males and females are in an euthyroid state during the spawning season.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The blood levels of gonadotropin II (GtH II), sex-steroid hormones, and thyroid hormones were determined in wild spermiating male striped bass (Morone saxatilis) in males and in females at various stages of final oocyte maturation (FOM), captured on their spawning grounds. The progression of spermiation was associated with increases in plasma GtH II and decreases in plasma testosterone (T), 11-ketotestosterone, and thyroxine (T4). Plasma triiodothyronine (T3) remained at high and relatively unchanged levels. Plasma levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) and 17,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P), the proposed maturation-inducing steroids (MIS) in striped bass, were low and unchanged during the same period. It was concluded that low progestogen levels are adequate to induce spermiation in striped bass, and that higher levels may be associated with spawning behavior. In the females, based on the profiles of the studied hormones, FOM was separated into two phases. Early FOM, which included germinal vesicle (GV) migration and lipid-droplet coalescence, was associated with elevations in plasma GtH II, T, and estradiol 17β. Late FOM, which included GV breakdown and yolk-globule coalescence, was associated with a further surge in plasma GtH II, increases in the levels of the two MIS, mainly 17,20β-P, and a drop in T4. Plasma T3 levels did not change during FOM. Examination of conjugated steroids demonstrated, in the males, a reduction in conjugated androgens at the peak of the spawning season and, in the females, a small increase in conjugated 17,20β-dihydroxylated and 5β- reduced, 3α-hydroxylated steroids after spawning. This is the most comprehensive report, to date, on the endocrine regulation of gonadal maturation in wild striped bass, demonstrating that a two-stage process of FOM is regulated by different endocrine signals, providing further evidence for the involvement of 17,20β-P as a MIS in the females, and indicating that both males and females are in an euthyroid state during the spawning season.

Schulz, R W; Wind, Van Der F; Janssen-Dommerholt, C; Peute, J; Mylonas, C C; Zohar, Y; Swanson, P; Goos, H J T

Modulation of testicular androgen production in adolescent African catfish (Clarias gariepinus) Journal Article

General and Comparative Endocrinology, 108 (1), pp. 56–66, 1997, ISSN: 00166480, (Publisher: Academic Press Inc.).

Abstract | Links | BibTeX

@article{schulz_modulation_1997,
title = {Modulation of testicular androgen production in adolescent African catfish (Clarias gariepinus)},
author = {R W Schulz and F Van Der Wind and C Janssen-Dommerholt and J Peute and C C Mylonas and Y Zohar and P Swanson and H J T Goos},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031260440&doi=10.1006%2fgcen.1997.6951&partnerID=40&md5=13ca91398eaf6fdeffb0cdab1a93756c},
doi = {10.1006/gcen.1997.6951},
issn = {00166480},
year = {1997},
date = {1997-01-01},
journal = {General and Comparative Endocrinology},
volume = {108},
number = {1},
pages = {56--66},
abstract = {At 6 months of age the first spermatozoa appear in the testes of the African catfish considered to be adolescent, since the development to adulthood (12 months of age) is accompanied by further morphological and functional differentiation of Leydig cells. There are increasing plasma levels of 11-ketotestosterone (11-KT) and an increasing responsiveness to luteinizing hormone (LH) of testicular androgen secretion in vitro. Whether treatment of adolescent males with key hormones of the brain-pituitary-gonad axis [gonadotropin-releasing hormone (GnRH), LH, and 11-KT] affects the testicular steroidogenic response to a challenge with LH in vitro 7 days later has been investigated. Injection of GnRH (2.5 μg chicken GnRH-II per kilogram of body weight), LH (25 μg/kg), or a high dose of 11-KT (50 μg/kg) down-regulated basal and LH-stimulated testicular androgen secretion to a minimum of 35% of control values. Treatment with LH was, moreover, associated with changes in the ultrastructure of Leydig cell mitochondria which were either swollen and had a less electron-dense matrix or showed an elongated shape. Conversely, a moderate dose of 11-KT (20 μg/kg) enhanced LH- stimulated, but not basal, androgen secretion in vitro to a maximum of 190% of control values. In view of the generally low LH plasma levels and of the steadily increasing 11-KT plasma levels during puberty, 11-KT may be involved in the up-regulation of the testicular steroidogenic capacity observed during development to full maturity.},
note = {Publisher: Academic Press Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; III, Woods L C; Zohar, Y

Cyto-histological examination of post-vitellogenesis and final oocyte maturation in captive-reared striped bass Journal Article

Journal of Fish Biology, 50 (1), pp. 34–49, 1997, ISSN: 00221112.

Abstract | Links | BibTeX

Mylonas, C C; Magnus, Y; Klebanov, Y; Gissis, A; Zohar, Y

Reproductive biology and endocrine regulation of final oocyte maturation of captive white bass Journal Article

Journal of Fish Biology, 51 (2), pp. 234–250, 1997, ISSN: 00221112.

Abstract | Links | BibTeX

@article{mylonas_reproductive_1997,
title = {Reproductive biology and endocrine regulation of final oocyte maturation of captive white bass},
author = {C C Mylonas and Y Magnus and Y Klebanov and A Gissis and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030741032&doi=10.1006%2fjfbi.1997.0433&partnerID=40&md5=aa2b0d7a5082efd22a1935123608e83a},
doi = {10.1006/jfbi.1997.0433},
issn = {00221112},
year = {1997},
date = {1997-01-01},
journal = {Journal of Fish Biology},
volume = {51},
number = {2},
pages = {234--250},
abstract = {The ovarian development, and plasma levels of gonadotropin II (GtH II) and sex-steroid hormones at the end of vitellogenesis were examined in captive white bass Morone chrysops. The changes in plasma hormone levels and oocyte morphology associated with gonadotropin-releasing hormone agonist (GnRHa)-induced final oocyte maturation (FOM) were studied. Although plasma 17β-oestradiol (E2) and oocyte diameter increased, there were no changes in GtH II, testosterone (T), 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) or 17,20β,21-dihydroxy-4-pregnen-3-one (17,20β,21-P) in non-hormone-treated females, and no FOM was observed. Treatment with a sustained-release GnRHa delivery system (GnRHa implant) induced two FOM cycles separated by about 24 h, with the release of approximately equal numbers of eggs in each spawn. Plasma GtH II levels were elevated significantly throughout FOM, reaching a maximum of 9.07 ± 1.55 ng ml-1 in ovulated fish. Both plasma E2 and T increased soon after the GnRHa treatment, but E2 declined in fish undergoing germinal vesicle (GV) migration. Plasma T increased further during FOM (7.55 ± 2.87 ng ml-1), but declined precipitously at ovulation. A surge in plasma 17,20β-P and 17,20β,21-P (4.11 ± 0.97 ng ml-1 and 3.10 ± 0.77 ng ml-1, respectively) was observed in females undergoing GV breakdown (GVBD). Based on the involvement of different sex-steroid hormones, FOM was separated into two stages. Early FOM included lipid-droplet coalescence and GV migration, and was associated with elevations in plasma GtH II and T. Late FOM included GVBD and yolk-globule coalescence, and was associated with elevations in plasma GtH II, 17,20β-P and 17,20β,21-P. The results of this study point to the absence of a surge in plasma GtH II as the missing link in the reproductive axis responsible for the failure of captive white bass to undergo FOM at the end of vitellogenesis. Sustained elevation of plasma GtH II via treatment with a GnRHa implant induced two consecutive spawns with an overall egg production two- to eightfold higher than previously obtained from captive broodstocks, and similar to annual egg production values reported for wild fish.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

The ovarian development, and plasma levels of gonadotropin II (GtH II) and sex-steroid hormones at the end of vitellogenesis were examined in captive white bass Morone chrysops. The changes in plasma hormone levels and oocyte morphology associated with gonadotropin-releasing hormone agonist (GnRHa)-induced final oocyte maturation (FOM) were studied. Although plasma 17β-oestradiol (E2) and oocyte diameter increased, there were no changes in GtH II, testosterone (T), 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) or 17,20β,21-dihydroxy-4-pregnen-3-one (17,20β,21-P) in non-hormone-treated females, and no FOM was observed. Treatment with a sustained-release GnRHa delivery system (GnRHa implant) induced two FOM cycles separated by about 24 h, with the release of approximately equal numbers of eggs in each spawn. Plasma GtH II levels were elevated significantly throughout FOM, reaching a maximum of 9.07 ± 1.55 ng ml-1 in ovulated fish. Both plasma E2 and T increased soon after the GnRHa treatment, but E2 declined in fish undergoing germinal vesicle (GV) migration. Plasma T increased further during FOM (7.55 ± 2.87 ng ml-1), but declined precipitously at ovulation. A surge in plasma 17,20β-P and 17,20β,21-P (4.11 ± 0.97 ng ml-1 and 3.10 ± 0.77 ng ml-1, respectively) was observed in females undergoing GV breakdown (GVBD). Based on the involvement of different sex-steroid hormones, FOM was separated into two stages. Early FOM included lipid-droplet coalescence and GV migration, and was associated with elevations in plasma GtH II and T. Late FOM included GVBD and yolk-globule coalescence, and was associated with elevations in plasma GtH II, 17,20β-P and 17,20β,21-P. The results of this study point to the absence of a surge in plasma GtH II as the missing link in the reproductive axis responsible for the failure of captive white bass to undergo FOM at the end of vitellogenesis. Sustained elevation of plasma GtH II via treatment with a GnRHa implant induced two consecutive spawns with an overall egg production two- to eightfold higher than previously obtained from captive broodstocks, and similar to annual egg production values reported for wild fish.

Larsson, D G J; Mylonas, C C; Zohar, Y; Crim, L W

Gonadotropin-releasing hormone analogue (GnRH-A) induces multiple ovulations of high-quality eggs in a cold-water, batch-spawning teleost, the yellowtail flounder (Pleuronectes ferrugineus) Journal Article

Canadian Journal of Fisheries and Aquatic Sciences, 54 (9), pp. 1957–1964, 1997, ISSN: 0706652X.

Abstract | Links | BibTeX

@article{larsson_gonadotropin-releasing_1997,
title = {Gonadotropin-releasing hormone analogue (GnRH-A) induces multiple ovulations of high-quality eggs in a cold-water, batch-spawning teleost, the yellowtail flounder (Pleuronectes ferrugineus)},
author = {D G J Larsson and C C Mylonas and Y Zohar and L W Crim},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031449685&doi=10.1139%2fcjfas-54-9-1957&partnerID=40&md5=52dbd73406a33867ec5f010c83f98ca6},
doi = {10.1139/cjfas-54-9-1957},
issn = {0706652X},
year = {1997},
date = {1997-01-01},
journal = {Canadian Journal of Fisheries and Aquatic Sciences},
volume = {54},
number = {9},
pages = {1957--1964},
abstract = {Sustained delivery systems for a gonadotropin-releasing hormone analogue (GnRH-A) were used for the first time in a cold-ocean teleost for inducing multiple ovulations. Intramuscular implants of 75-224 μg/kg GnRH-A ((D-Ala6,Pro9-NHEt)LHRH) were administered to female yellowtail flounder (Pleuronectes ferrugineus) either as a cholesterol pellet or as biodegradable microspheres. Females implanted with GnRH-A ovulated 3-4 weeks earlier than controls, producing multiple batches of high-quality eggs (average rates of fertilization 66-68% and hatching 55-60%); control fish eggs had significantly lower fertilization (39%) and hatching rates (25%). GnRH-A treatment doubled the egg production, synchronized the females, and shortened the interovulatory periods. The proportion of round, clear, and floating eggs lacking a perivitelline space before fertilization was an indicator of the fertilization (r2= 0.60) and hatching (r2 = 0.56) success. Moreover, egg collections of less than 10 mL varied greatly in quality, whereas larger batches, generally promoted by GnRH-A, consisted of relatively high-quality eggs. GnRH-A treated fish had increased plasma levels of estradiol- 17β 4 days after implantation. A model for prediction of the time between hormone treatment and first spawning (T; days) was developed using the initial follicle diameter (D; μm) as the only predictor (T = 365(D - 380)-082; r2 = 0.91).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Gissis, A; Magnus, Y; Zohar, Y

Hormonal changes in male white bass (Morone chrysops) and evaluation of milt quality after treatment with a sustained-release GnRHa delivery system Journal Article

Aquaculture, 153 (3-4), pp. 301–311, 1997, ISSN: 00448486.

Abstract | Links | BibTeX

@article{mylonas_hormonal_1997,
title = {Hormonal changes in male white bass (Morone chrysops) and evaluation of milt quality after treatment with a sustained-release GnRHa delivery system},
author = {C C Mylonas and A Gissis and Y Magnus and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030759556&doi=10.1016%2fS0044-8486%2897%2987566-7&partnerID=40&md5=46bd2d2d502a25d0f3ec6e54a305aba9},
doi = {10.1016/S0044-8486(97)87566-7},
issn = {00448486},
year = {1997},
date = {1997-01-01},
journal = {Aquaculture},
volume = {153},
number = {3-4},
pages = {301--311},
abstract = {Captive white bass, (Morone chrysops) were exposed to an increase in temperature and treated with a gonadotropin-releasing hormone agonist (GnRHa) delivery system during the spermiation period. Circulating levels of various reproductive hormones, and milt production and quality were examined before and after GnRHa treatment. Circulating levels of gonadotropin II (GtH II) prior to GnRHa treatment were below the assay detection limit (0.4 ng ml-1), while mean (±SEM) plasma levels of 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P) were 0.09 ± 0.03 ng ml-1 testosterone (T) levels were 0,79 ± 0.11 ng ml-1 and 11-ketotestosterone (11-KT) levels were 1.7 ± 0.3 ng ml-1. Treatment with the GnRHa delivery system induced significant increases in plasma GtH 11 and 17,20β-P after 7 days, whereas T and 11-KT were unaffected. Plasma 17α,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P) remained unchanged during the experiment with a mean of 0.55 ± 0.05 ng ml-1. Mean total expressible milt increased significantly after treatment with the GnRHa delivery system, from 2.0 ± 0.1 ml kg-1 body weight on day 0 to 3.6 ± 0.5 ml kg-1 on day 7. Milt production remained constant in saline-injected control fish and averaged 2.1 ± 0.2 ml kg-1. Sperm density, motility and fertilization percentage of total inseminated eggs did not differ between milt from GnRHa- and saline-injected fish, and averaged 52 ± 2 x 109 spermatozoa ml-1, 50 ± 4% motile spermatozoa and 60 ± 5% fertilized eggs, respectively. These results demonstrate the effectiveness of sustained GnRHa treatment in enhancing mill production in white bass, without negatively affecting mill quality. It is assumed that enhancement of milt production is caused by high circulating GtH II levels, via the action of 17.20β-P.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Scott, A P; Vermeirssen, E L M; Zohar, Y

Changes in plasma gonadotropin II and sex steroid hormones, and sperm production of striped bass after treatment with controlled-release gonadotropin-releasing hormone agonist-delivery systems Journal Article

Biology of Reproduction, 57 (3), pp. 669–675, 1997, ISSN: 00063363.

Abstract | Links | BibTeX

@article{mylonas_changes_1997,
title = {Changes in plasma gonadotropin II and sex steroid hormones, and sperm production of striped bass after treatment with controlled-release gonadotropin-releasing hormone agonist-delivery systems},
author = {C C Mylonas and A P Scott and E L M Vermeirssen and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030838590&doi=10.1095%2fbiolreprod57.3.669&partnerID=40&md5=611a3480a18c07ff0a4dcaa0996716a2},
doi = {10.1095/biolreprod57.3.669},
issn = {00063363},
year = {1997},
date = {1997-01-01},
journal = {Biology of Reproduction},
volume = {57},
number = {3},
pages = {669--675},
abstract = {Spermiating striped bass, a perciform fish, were treated with two controlled-release gonadotropin-releasing hormone agonist (GnRHa)-delivery systems, and the resulting changes in plasma gonadotropin II (GTH II), testosterone (T), 11-ketotestosterone (11-KT), 17,20β-dihydroxy-4-pregnen- 3-one (17,20β-P), and 17,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P) were correlated with changes in milt production and sperm density. GnRHa- delivery systems induced a sustained elevation of plasma GnRHa and GTH II for 14 days. Plasma T levels were unchanged after GnRHa treatment, while 11-KT levels increased significantly. Plasma 17,20β-P also increased after GnRHa treatment and remained elevated compared to levels in controls, while plasma 17,20β,21-P levels were unaffected. Both GnRHa-delivery systems induced many-fold increases in total expressible milt, lasting throughout the 14 days of the study. Sperm density decreased 2 days after GnRHa treatment, with a subsequent increase by Day 7. This study demonstrates that GnRHa-delivery systems induce a sustained elevation of plasma GTH II levels in striped bass, resulting in a long-term enhancement of milt production. The endocrine changes observed suggest that 11-KT and 17,20β-P, but not 17,20β,21-P, are mediating the effects of GTH II on spermiation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

1996

Sorbera, L A; Mylonas, C C; Zanuy, S; Carrillo, M; Zohar, Y

Sustained administration of GnRHa increases milt volume without altering sperm counts in the sea bass Journal Article

Journal of Experimental Zoology, 276 (5), pp. 361–368, 1996, ISSN: 0022104X.

Abstract | Links | BibTeX

@article{sorbera_sustained_1996,
title = {Sustained administration of GnRHa increases milt volume without altering sperm counts in the sea bass},
author = {L A Sorbera and C C Mylonas and S Zanuy and M Carrillo and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030443470&doi=10.1002%2f%28SICI%291097-010X%2819961201%29276%3a5%3c361%3a%3aAID-JEZ6%3e3.0.CO%3b2-M&partnerID=40&md5=da145966d5c694db401ff311d820caab},
doi = {10.1002/(SICI)1097-010X(19961201)276:5<361::AID-JEZ6>3.0.CO;2-M},
issn = {0022104X},
year = {1996},
date = {1996-01-01},
journal = {Journal of Experimental Zoology},
volume = {276},
number = {5},
pages = {361--368},
abstract = {The role of gonadotropin-releasing hormone (GnRH) in spermiogenesis and spermiation is not well understood. This study examined the effects of different modes of administration of a GnRH analog (GnRHa; [D-Ala6, Pro9NEt]-mGnRH) on spermiation in the sea bass, Dicentrarchus labrax. Groups of sea bass received either GnRHa injection in saline (I; 25 μg/kg body weight [BW] or one of three types of GnRHa sustained release polymeric device: a fast-releasing implant (ethylene-vinyl acetate copolymer [EVAc]; 100 μg/kg BW), a slower-releasing implant (ethylene-vinyl acetate copolymer [EVSL]; 100 μg/kg BW), or biodegradable microspheres (M; 50 μg/kg BW). Total expressible milt was collected and assessed for volume, motility, and counts at various intervals for 44 days. Untreated males produced a total of 9.4 ± 3.4 ml/kg BW (mean ± SEM) of milt over the 44-day experimental period, with milt production ending by day 28. All GnRHa treatments stimulated a significant increase in total milt volume (ml/kg BW) peaking by day 2 (I: 11.8 ± 1.8) or day 7 (EVAc: 20.0 ± 1.5; M: 26.8 ± 2.7; EVSL: 27.9 ± 4.3) posttreatment. While milt volumes in injected males returned to control values by day 14, all groups treated with sustained GnRHa delivery systems maintained significantly elevated milt volumes for 21 days (EVAc group) or 35 days (EVSL and M groups). Sperm motility was consistently good to excellent (70-100% vigorously active) in all groups when expressible milt volume was above 1.0 ml, and there were no significant differences in sperm counts (averaging 5.5 ± 0.1 x 109 spermatozoa/ml). These data show that sustained administration of GnRHa significantly increases and prolongs spermiation in the sea bass without altering sperm concentration or quality.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Holland, M C; Mylonas, C C; Zohar, Y

Sperm characteristics of precocious 1-year-old male striped bass Morone saxatilis Journal Article

Journal of the World Aquaculture Society, 27 (2), pp. 208–212, 1996, ISSN: 08938849.

Abstract | Links | BibTeX

Mylonas, C C; Magnus, Y; Gissis, A; Klebanov, Y; Zohar, Y

Application of controlled-release, GnRHa-delivery systems in commercial production of white bass X striped bass hybrids (sunshine bass), using captive broodstocks Journal Article

Aquaculture, 140 (3), pp. 265–280, 1996, ISSN: 00448486, (Publisher: Elsevier).

Abstract | Links | BibTeX

@article{mylonas_application_1996,
title = {Application of controlled-release, GnRHa-delivery systems in commercial production of white bass X striped bass hybrids (sunshine bass), using captive broodstocks},
author = {C C Mylonas and Y Magnus and A Gissis and Y Klebanov and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0000911285&doi=10.1016%2f0044-8486%2895%2901178-1&partnerID=40&md5=5c8c94d7c52f9d763d1866eec84ca115},
doi = {10.1016/0044-8486(95)01178-1},
issn = {00448486},
year = {1996},
date = {1996-01-01},
journal = {Aquaculture},
volume = {140},
number = {3},
pages = {265--280},
abstract = {Hatchery-produced white bass (Morone chrysops) and striped bass (M. saxatilis) reared to maturity in a commercial aquaculture facility, were successfully spawned using controlled-release delivery systems containing the gonadotropin-releasing hormone analog DAla6, Pro9[NEt]-GnRH (GnRHa). Two-year-old white bass females (mean weight, 0.81 kg) were implanted with different polymer-based, GnRHa delivery systems at doses ranging from 40 to 89 μg GnRHa kg-1 body weight. GnRHa treatment on 20 February 1994, when females contained oocytes up to 720 μm in diameter, induced ovulation of all fish between 35 to 82 h after treatment. The white bass eggs produced were fertilized with sperm from striped bass for the production of sunshine bass. An average of 294500 eggs kg-1 were produced, with a mean fertility of 81.2%, 24 h survival of 46.5%, and overall hatching success of 45%. Survival from hatch to 30 days post-hatch was 78% and the fry weighed between 0.07 and 0.1 g. Overripening of eggs began within 1 h from ovulation and maximum fertilization (60%) was observed when eggs were stripped 0.5 h after ovulation. Fertilization success decreased thereafter to 31% and 10% by 1 h and 3 h after ovulation, respectively. Control fish not treated with GnRHa did not show any signs of final oocyte maturation during the period of the study. GnRHa administration via controlled-release delivery systems appears to be a very effective method for inducing high fecundity ovulation of captive white bass broodstocks, and producing eggs of high fertility and hatching success.},
note = {Publisher: Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

1995

Mylonas, C C; Tabata, Y; Langer, R; Zohar, Y

Preparation and evaluation of polyanhydride microspheres containing gonadotropin-releasing hormone (GnRH), for inducing ovulation and spermiation in fish Journal Article

Journal of Controlled Release, 35 (1), pp. 23–34, 1995, ISSN: 01683659.

Abstract | Links | BibTeX

@article{mylonas_preparation_1995,
title = {Preparation and evaluation of polyanhydride microspheres containing gonadotropin-releasing hormone (GnRH), for inducing ovulation and spermiation in fish},
author = {C C Mylonas and Y Tabata and R Langer and Y Zohar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029072968&doi=10.1016%2f0168-3659%2895%2900009-W&partnerID=40&md5=7ed29a4581d9db234fa69df97c5fbe8b},
doi = {10.1016/0168-3659(95)00009-W},
issn = {01683659},
year = {1995},
date = {1995-01-01},
journal = {Journal of Controlled Release},
volume = {35},
number = {1},
pages = {23--34},
abstract = {We developed a microspheric delivery system for a synthetic analog of gonadotropin-releasing hormone (GnRHa) for inducing ovulation and enhancing spermiation in broodfish which, relative to mammals, are maintained at low temperatures (10-22°C). The microspheres were based on a biodegradable copolymer of fatty acid dimer and sebacic acid (p[FAD-SA]) of a 25:75 molar ratio, and were prepared by a solvent evaporation method, using double emulsion. The GnRH analog [d-Ala6, Pro9NEt]-GnRH was entrapped into the microspheres at 3% loading with 86% (± 5.4) efficiency. The prepared microspheres had a spherical shape, with diameters from 10 to 240 μm. In vitro, GnRHa was released for at least 90 days at 15°C, following an initial release of 8.8% of the total amount. The release during the first 30 days followed first-order kinetics described by the equation GnRHa (μg) = 1.7[day]0.33 (R2=0.99), and zero-order kinetics thereafter, described by the equation GnRHa (μg) = 0.027[day] + 4.5 (R2 = 0.98). Plasma GnRHa levels of microsphere-injected striped bass (Morone saxatilis) remained elevated for at least 8 weeks at 16°C, although the levels dropped dramatically after day 28. Microsphere injection of post-vitellogenic striped bass females and Atlantic salmon (Salmo salar) induced 100% ovulation by day 11 and 15 after treatment, respectively. Similar treatment induced a 4-10-fold increase in sperm production of striped bass males for at least 14 days after treatment and resulted in a 2.5-fold increase of expressible sperm volume of male Atlantic salmon 10 days after treatment. © 1995.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Mylonas, C C; Zohar, Y; Richardson, B M; Minkkinen, S P

Induced Spawning of Wild American Shad Alosa sapidissima Using Sustained Administration of Gonadotropin‐Releasing Hormone Analog (GnRHa) Journal Article

Journal of the World Aquaculture Society, 26 (3), pp. 240–251, 1995, ISSN: 08938849.

Abstract | Links | BibTeX

1994

Mylonas, C C; Sullivan, C V; Hinshaw, J M

Thyroid hormones in brown trout (Salmo trutta) reproduction and early development Journal Article

Fish Physiology and Biochemistry, 13 (6), pp. 485–493, 1994, ISSN: 09201742, (Publisher: Kluwer Academic Publishers).

Abstract | Links | BibTeX

@article{mylonas_thyroid_1994,
title = {Thyroid hormones in brown trout (Salmo trutta) reproduction and early development},
author = {C C Mylonas and C V Sullivan and J M Hinshaw},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028190849&doi=10.1007%2fBF00004331&partnerID=40&md5=4c117fff843229fa02b99bbd3ebb7664},
doi = {10.1007/BF00004331},
issn = {09201742},
year = {1994},
date = {1994-01-01},
journal = {Fish Physiology and Biochemistry},
volume = {13},
number = {6},
pages = {485--493},
abstract = {Gravid brown trout (Salmo trutta) females were injected with various doses of a synthetic gonadotropin-releasing hormone analog (GnRHa), given with or without an injection of triiodothyronine (T3), in order to investigate the potential of T3 (a) to enhance the stimulatory effect of GnRHa on ovulation, and (b) to enhance the growth and survival of the produced progeny. From the time the hormonal treatments were initiated until ovulation was detected 5-38 days later, endogenous plasma T3 levels increased from an average of 3.6 to 11.6 ng ml-1. Injection with 20 mg T3 kg-1 body weight, further elevated plasma T3 levels at ovulation (16.0 ng ml-1. Mean time to ovulation was reduced significantly in fish injected with 10 μg kg-1 of GnRHa, whereas treatment with lower doses was ineffective. Injection with T3 did not enhance the ovulatory response of brown trout to GnRHa. Unfertilized eggs obtained from T3-injected females had a higher T3 content, suggesting a transfer of T3 from the maternal circulation into the oocytes. Maternal T3 injection had no effect on egg fertilization rates, embryo survival to eyeing and hatching, or the prevalence of abnormal larvae at the time of hatching. Length and weight gain of the progeny during yolk absorption was also not influenced by maternal T3 treatment. At the completion of yolk-sac absorption, progeny from females injected with T3 had a higher prevalence of skeletal abnormalities than controls. The results suggest that in teleosts like brown trout, which have high endogenous circulating T3 levels, treatment of females with T3 does not enhance responsiveness to GnRHa and it has the potential for deleterious effects on their offspring. © 1994 Kugler Publications.},
note = {Publisher: Kluwer Academic Publishers},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

1992

Mylonas, C C; Hinshaw, J M; Sullivan, C V

GnRHa-induced ovulation of brown trout (Salmo trutta) and its effects on egg quality Journal Article

Aquaculture, 106 (3-4), pp. 379–392, 1992, ISSN: 00448486.

Abstract | Links | BibTeX