Irene Sigelaki

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2024

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

2021

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

2020

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},
url = {https://pdf.sciencedirectassets.com/271224/1-s2.0-S0044848619X00186/1-s2.0-S0044848619326079/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEPb%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJGMEQCIEKiYyI3Ycqx63hZp9lWGRWcsYrKIYv1T3L%2FsVCZBXRLAiBT0R83WGN4OE%2BrF0Q2Iy1lEA1RMiC7UHkh9ziKtbtPFyq9Awie%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDA1OTAwMzU0Njg2NSIM4gS7FIQr6cp11X0pKpED%2FgoocYExFYA%2FLlo%2FsWYyzGVglS%2F6nkMLmZ%2ByMzYN3rGpSS8JnjWll%2BVBi9%2BQFiROQwjuZa3a%2FSAaLIRpIrqFJha5oaFJ1uYLfF5jH%2F62tRXpLB7sJQIii2PJpKgyFJfvrf62rUnhlVgggKANKBLslRjOQC8OAM6eh7pVSbTEeL5L2u1qmbgrN9sofvTRJjUhHYH6khAKTlWIN9Ms%2Bh%2FOYQd4hTDsXfs%2FCLNjH1yWN8vg5BwKN2LzwxBg4GRzlAPYuHtntee5qvC66DnoixqeUW9OTaf0KEv%2BJzwpT%2BfYdAWgXADTRYyGrESV0DPkx1DtTDORWmCg3rcA%2B2uudNnFW9OTbzBVItC8f9kdRQFCebf%2B8oUZjaQmpd6%2F9JT5xdXN8nmLLSD4B9f7HP4U9JMaLZ2mn8tdIZKFXY4RDIy4GDSatfnMgb2XPIRgWuB2PVcXkSf5FZFJA0%2BJ%2BNmXPCeB%2Brw8JB7L5LUaBqTpvV1HsryDzFT1ldBoXdenkb%2BNqHmCOXfEy1ym7f%2F1nzvO3WzGaPowo8Lu8QU67AFeu9OlXRP%2B4WswxYSqWZm5HLdCiyyyTFj51GbkOMdIlPKhnTIAVKhItiILXu%2BV72DuKLFa6Oi1iniDXP8KMQsuMUWjfimxW%2BdiyAeYmLmZMp09D130PUxEC8%2FPLMEyv0fXQY5U1q%2FlsoZwTHIjrGSmzdX9AV1AlVjKx9p6qyJ4fvBE%2BYBdfStdOdO5NaTrkff5pVoEXP1prc2HPySs%2BQ%2F%2FewSGTNjeUJHZDoVDpd17GFYHLwhoEHbOGt54OFz4kAAaHRh3S60uJxwRA6gSMwO%2But3nF4rDdIJSmL3QNM%2BO%2FY%2FK%2FF1ZYvaprhEPdQ%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20200206T064417Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYU72A2J4J%2F20200206%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=ea8ff719b68d48407c48376c1561efa9042ae1f7598e65d269d5ba562bbe8262&hash=a4e2bfffdc3a781228d030d4043afc6504ec3ebb0665612a27237bc5a0c78826&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S0044848619326079&tid=spdf-0066909c-c2cd-42a5-964f-1088618050da&sid=9f8cc34964ace14eda7b5f0927495aa20829gxrqb&type=client},
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}
}

2019

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

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

2018

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}
}

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

2016

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}
}

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}
}

2013

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.

2008

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}
}

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.

2004

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}
}

2003

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}
}