2023 |
Varamogianni-Mamatsi, Despoina; Nunes, Maria João; Marques, Vanda; Anastasiou, Thekla I; Kagiampaki, Eirini; Vernadou, Emmanouela; Dailianis, Thanos; Kalogerakis, Nicolas; Branco, Luís C; Rodrigues, Cecília M P; Sobral, Rita G; Gaudêncio, Susana P; Mandalakis, Manolis Marine Drugs, 21 (12), pp. 612, 2023, ISSN: 1660-3397. @article{varamogianni-mamatsi_comparative_2023, title = {Comparative Chemical Profiling and Antimicrobial/Anticancer Evaluation of Extracts from Farmed versus Wild Agelas oroides and Sarcotragus foetidus Sponges}, author = {Despoina Varamogianni-Mamatsi and Maria João Nunes and Vanda Marques and Thekla I Anastasiou and Eirini Kagiampaki and Emmanouela Vernadou and Thanos Dailianis and Nicolas Kalogerakis and Luís C Branco and Cecília M P Rodrigues and Rita G Sobral and Susana P Gaudêncio and Manolis Mandalakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/12/2023-Varamogianni-Mamatsi-marinedrugs-62.pdf https://www.mdpi.com/1660-3397/21/12/612}, doi = {10.3390/md21120612}, issn = {1660-3397}, year = {2023}, date = {2023-12-04}, urldate = {2023-12-05}, journal = {Marine Drugs}, volume = {21}, number = {12}, pages = {612}, abstract = {Marine sponges are highly efficient in removing organic pollutants and their cultivation, adjacent to fish farms, is increasingly considered as a strategy for improving seawater quality. Moreover, these invertebrates produce a plethora of bioactive metabolites, which could translate into an extra profit for the aquaculture sector. Here, we investigated the chemical profile and bioactivity of two Mediterranean species (i.e., Agelas oroides and Sarcotragus foetidus) and we assessed whether cultivated sponges differed substantially from their wild counterparts. Metabolomic analysis of crude sponge extracts revealed species-specific chemical patterns, with A. oroides and S. foetidus dominated by alkaloids and lipids, respectively. More importantly, farmed and wild explants of each species demonstrated similar chemical fingerprints, with the majority of the metabolites showing modest differences on a sponge mass-normalized basis. Furthermore, farmed sponge extracts presented similar or slightly lower antibacterial activity against methicillin-resistant Staphylococcus aureus, compared to the extracts resulting from wild sponges. Anticancer assays against human colorectal carcinoma cells (HCT-116) revealed marginally active extracts from both wild and farmed S. foetidus populations. Our study highlights that, besides mitigating organic pollution in fish aquaculture, sponge farming can serve as a valuable resource of biomolecules, with promising potential in pharmaceutical and biomedical applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Marine sponges are highly efficient in removing organic pollutants and their cultivation, adjacent to fish farms, is increasingly considered as a strategy for improving seawater quality. Moreover, these invertebrates produce a plethora of bioactive metabolites, which could translate into an extra profit for the aquaculture sector. Here, we investigated the chemical profile and bioactivity of two Mediterranean species (i.e., Agelas oroides and Sarcotragus foetidus) and we assessed whether cultivated sponges differed substantially from their wild counterparts. Metabolomic analysis of crude sponge extracts revealed species-specific chemical patterns, with A. oroides and S. foetidus dominated by alkaloids and lipids, respectively. More importantly, farmed and wild explants of each species demonstrated similar chemical fingerprints, with the majority of the metabolites showing modest differences on a sponge mass-normalized basis. Furthermore, farmed sponge extracts presented similar or slightly lower antibacterial activity against methicillin-resistant Staphylococcus aureus, compared to the extracts resulting from wild sponges. Anticancer assays against human colorectal carcinoma cells (HCT-116) revealed marginally active extracts from both wild and farmed S. foetidus populations. Our study highlights that, besides mitigating organic pollution in fish aquaculture, sponge farming can serve as a valuable resource of biomolecules, with promising potential in pharmaceutical and biomedical applications. |
Anastasiou, Thekla I; Kagiampaki, Eirini; Kondylatos, Gerasimos; Tselepides, Anastasios; Peristeraki, Panagiota; Mandalakis, Manolis Marine Drugs, 21 (10), pp. 520, 2023, ISSN: 1660-3397. @article{anastasiou_assessing_2023, title = {Assessing the Toxicity of Lagocephalus sceleratus Pufferfish from the Southeastern Aegean Sea and the Relationship of Tetrodotoxin with Gonadal Hormones}, author = {Thekla I Anastasiou and Eirini Kagiampaki and Gerasimos Kondylatos and Anastasios Tselepides and Panagiota Peristeraki and Manolis Mandalakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/10/2023-Anastasiou-Mardrugs-55.pdf https://www.mdpi.com/1660-3397/21/10/520}, doi = {10.3390/md21100520}, issn = {1660-3397}, year = {2023}, date = {2023-10-11}, urldate = {2023-10-17}, journal = {Marine Drugs}, volume = {21}, number = {10}, pages = {520}, abstract = {Given the dramatic increase in the L. sceleratus population in the southeastern Aegean Sea, there is growing interest in assessing the toxicity of this pufferfish and the factors controlling its tetrodotoxin (TTX) content. In the present study, liver, gonads, muscle and skin of 37 L. sceleratus specimens collected during May and June 2021 from the island of Rhodes, Greece, were subjected to multi-analyte profiling using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to quantitate TTX and evaluate whether this biotoxin interrelates with hormones. TTX and its analogues 4-epiTTX, 11-deoxyTTX, 11-norTTX-6-ol, 4,9-anhydroTTX and 5,11/6,11-dideoxyTTX were detected in all tissue types. Liver and gonads were the most toxic tissues, with the highest TTX concentrations being observed in the ovaries of female specimens. Only 22% of the analyzed muscle samples were non-toxic according to the Japanese toxicity threshold (2.2 μg TTX eq g−1), confirming the high poisoning risk from the inadvertent consumption of this species. Four steroid hormones (i.e., cortisol, testosterone, androstenedione and β-estradiol) and the gonadotropin-releasing hormone (GnRH) were detected in the gonads. Androstenedione dominated in female specimens, while GnRH was more abundant in males. A positive correlation of TTX and its analogues with β-estradiol was observed. However, a model incorporating sex rather than β-estradiol as the independent variable proven to be more efficient in predicting TTX concentration, implying that other sex-related characteristics are more important than specific hormone-regulated processes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Given the dramatic increase in the L. sceleratus population in the southeastern Aegean Sea, there is growing interest in assessing the toxicity of this pufferfish and the factors controlling its tetrodotoxin (TTX) content. In the present study, liver, gonads, muscle and skin of 37 L. sceleratus specimens collected during May and June 2021 from the island of Rhodes, Greece, were subjected to multi-analyte profiling using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to quantitate TTX and evaluate whether this biotoxin interrelates with hormones. TTX and its analogues 4-epiTTX, 11-deoxyTTX, 11-norTTX-6-ol, 4,9-anhydroTTX and 5,11/6,11-dideoxyTTX were detected in all tissue types. Liver and gonads were the most toxic tissues, with the highest TTX concentrations being observed in the ovaries of female specimens. Only 22% of the analyzed muscle samples were non-toxic according to the Japanese toxicity threshold (2.2 μg TTX eq g−1), confirming the high poisoning risk from the inadvertent consumption of this species. Four steroid hormones (i.e., cortisol, testosterone, androstenedione and β-estradiol) and the gonadotropin-releasing hormone (GnRH) were detected in the gonads. Androstenedione dominated in female specimens, while GnRH was more abundant in males. A positive correlation of TTX and its analogues with β-estradiol was observed. However, a model incorporating sex rather than β-estradiol as the independent variable proven to be more efficient in predicting TTX concentration, implying that other sex-related characteristics are more important than specific hormone-regulated processes. |
Varamogianni-Mamatsi, Despoina; Anastasiou, Thekla I; Vernadou, Emmanouela; Kouvarakis, Nikos; Kagiampaki, Eirini; Kalogerakis, Nicolas; Dailianis, Thanos; Mandalakis, Manolis Uptake of aquaculture-related dissolved organic pollutants by marine sponges: Kinetics and mechanistic insights from a laboratory study Journal Article Science of The Total Environment, 899 , pp. 165601, 2023, ISSN: 00489697. @article{varamogianni-mamatsi_uptake_2023, title = {Uptake of aquaculture-related dissolved organic pollutants by marine sponges: Kinetics and mechanistic insights from a laboratory study}, author = {Despoina Varamogianni-Mamatsi and Thekla I Anastasiou and Emmanouela Vernadou and Nikos Kouvarakis and Eirini Kagiampaki and Nicolas Kalogerakis and Thanos Dailianis and Manolis Mandalakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/08/2023-Varamogianni-Mamatsi-STEnv-40-preprint.pdf https://linkinghub.elsevier.com/retrieve/pii/S0048969723042249}, doi = {10.1016/j.scitotenv.2023.165601}, issn = {00489697}, year = {2023}, date = {2023-08-01}, urldate = {2023-08-14}, journal = {Science of The Total Environment}, volume = {899}, pages = {165601}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Polymenakou, Paraskevi N; Nomikou, Paraskevi; Hannington, Mark; Petersen, Sven; Kilias, Stephanos P; Anastasiou, Thekla I; Papadimitriou, Vasiliki; Zaka, Eleutheria; Kristoffersen, Jon Bent; Lampridou, Danai; Wind, Sandra; Heinath, Verena; Lange, Sabine; Magoulas, Antonios Taxonomic diversity of microbial communities in sub-seafloor hydrothermal sediments of the active Santorini-Kolumbo volcanic field Journal Article Frontiers in Microbiology, 14 , pp. 1188544, 2023, ISSN: 1664-302X. @article{polymenakou_taxonomic_2023, title = {Taxonomic diversity of microbial communities in sub-seafloor hydrothermal sediments of the active Santorini-Kolumbo volcanic field}, author = {Paraskevi N Polymenakou and Paraskevi Nomikou and Mark Hannington and Sven Petersen and Stephanos P Kilias and Thekla I Anastasiou and Vasiliki Papadimitriou and Eleutheria Zaka and Jon Bent Kristoffersen and Danai Lampridou and Sandra Wind and Verena Heinath and Sabine Lange and Antonios Magoulas}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/07/2023-Polymenakou-FrontMicro-35.pdf https://www.frontiersin.org/articles/10.3389/fmicb.2023.1188544/full}, doi = {10.3389/fmicb.2023.1188544}, issn = {1664-302X}, year = {2023}, date = {2023-07-06}, urldate = {2023-07-06}, journal = {Frontiers in Microbiology}, volume = {14}, pages = {1188544}, abstract = {Introduction Active hydrothermal vents of volcanic origin provide a remarkable manifestation of life on Earth under extreme conditions, which may have consequences for our understanding of habitability on other terrestrial bodies as well. Methods Here, we performed for the first time Illumina sequencing of bacterial and archaeal communities on sub-seafloor samples collected from the Santorini-Kolumbo volcanic field. A total of 19 (3-m long) gravity corers were collected and processed for microbial community analysis. Results From a total of 6,46,671 produced V4 sequences for all samples, a total of 10,496 different Operational Taxonomic Units (OTUs) were identified that were assigned to 40 bacterial and 9 archaeal phyla and 14 candidate divisions. On average, the most abundant phyla in all samples were Chloroflexi (Chloroflexota) (24.62%), followed by Proteobacteria (Pseudomonadota) (11.29%), Firmicutes (Bacillota) (10.73%), Crenarchaeota (Thermoproteota) (8.55%), and Acidobacteria (Acidobacteriota) (8.07%). At the genus level, a total of 286 known genera and candidate genera were mostly dominated by members of Bacillus, Thermoflexus, Desulfatiglans, Pseudoalteromonas , and Pseudomonas . Discussion In most of the stations, the Chao1 values at the deeper layers were comparable to the surface sediment samples denoting the high diversity in the subsurface of these ecosystems. Heatmap analysis based on the 100 most abundant OTUs, grouped the sampling stations according to their geographical location, placing together the two hottest stations (up to 99°C). This result indicates that this specific area within the active Kolumbo crater create a distinct niche, where microorganisms with adaptation strategies to withstand heat stresses can thrive, such as the endospore-forming Firmicutes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Introduction Active hydrothermal vents of volcanic origin provide a remarkable manifestation of life on Earth under extreme conditions, which may have consequences for our understanding of habitability on other terrestrial bodies as well. Methods Here, we performed for the first time Illumina sequencing of bacterial and archaeal communities on sub-seafloor samples collected from the Santorini-Kolumbo volcanic field. A total of 19 (3-m long) gravity corers were collected and processed for microbial community analysis. Results From a total of 6,46,671 produced V4 sequences for all samples, a total of 10,496 different Operational Taxonomic Units (OTUs) were identified that were assigned to 40 bacterial and 9 archaeal phyla and 14 candidate divisions. On average, the most abundant phyla in all samples were Chloroflexi (Chloroflexota) (24.62%), followed by Proteobacteria (Pseudomonadota) (11.29%), Firmicutes (Bacillota) (10.73%), Crenarchaeota (Thermoproteota) (8.55%), and Acidobacteria (Acidobacteriota) (8.07%). At the genus level, a total of 286 known genera and candidate genera were mostly dominated by members of Bacillus, Thermoflexus, Desulfatiglans, Pseudoalteromonas , and Pseudomonas . Discussion In most of the stations, the Chao1 values at the deeper layers were comparable to the surface sediment samples denoting the high diversity in the subsurface of these ecosystems. Heatmap analysis based on the 100 most abundant OTUs, grouped the sampling stations according to their geographical location, placing together the two hottest stations (up to 99°C). This result indicates that this specific area within the active Kolumbo crater create a distinct niche, where microorganisms with adaptation strategies to withstand heat stresses can thrive, such as the endospore-forming Firmicutes. |
2022 |
Varamogianni-Mamatsi, Despoina; Anastasiou, Thekla I; Vernadou, Emmanouela; Papandroulakis, Nikos; Kalogerakis, Nicolas; Dailianis, Thanos; Mandalakis, Manolis A Multi-Species Investigation of Sponges’ Filtering Activity towards Marine Microalgae Journal Article Marine Drugs, 20 (1), pp. 24, 2022, ISSN: 1660-3397. @article{varamogianni-mamatsi_multi-species_2022, title = {A Multi-Species Investigation of Sponges’ Filtering Activity towards Marine Microalgae}, author = {Despoina Varamogianni-Mamatsi and Thekla I Anastasiou and Emmanouela Vernadou and Nikos Papandroulakis and Nicolas Kalogerakis and Thanos Dailianis and Manolis Mandalakis}, url = {https://www.mdpi.com/1660-3397/20/1/24}, doi = {10.3390/md20010024}, issn = {1660-3397}, year = {2022}, date = {2022-01-01}, urldate = {2022-02-28}, journal = {Marine Drugs}, volume = {20}, number = {1}, pages = {24}, abstract = {Chronic discharge of surplus organic matter is a typical side effect of fish aquaculture, occasionally leading to coastal eutrophication and excessive phytoplankton growth. Owing to their innate filter-feeding capacity, marine sponges could mitigate environmental impact under integrated multitrophic aquaculture (IMTA) scenarios. Herein, we investigated the clearance capacity of four ubiquitous Mediterranean sponges (Agelas oroides, Axinella cannabina, Chondrosia reniformis and Sarcotragus foetidus) against three microalgal substrates with different size/motility characteristics: the nanophytoplankton Nannochloropsis sp. (textasciitilde3.2 μm, nonmotile) and Isochrysis sp. (textasciitilde3.8 μm, motile), as well as the diatom Phaeodactylum tricornutum (textasciitilde21.7 μm, nonmotile). In vitro cleaning experiments were conducted using sponge explants in 1 L of natural seawater and applying different microalgal cell concentrations under light/dark conditions. The investigated sponges exhibited a wide range of retention efficiencies for the different phytoplankton cells, with the lowest average values found for A. cannabina (37%) and the highest for A. oroides (70%). The latter could filter up to 14.1 mL seawater per hour and gram of sponge wet weight, by retaining 100% of Isochrysis at a density of 105 cells mL−1, under darkness. Our results highlight differences in filtering capacity among sponge species and preferences for microalgal substrates with distinct size and motility traits.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Chronic discharge of surplus organic matter is a typical side effect of fish aquaculture, occasionally leading to coastal eutrophication and excessive phytoplankton growth. Owing to their innate filter-feeding capacity, marine sponges could mitigate environmental impact under integrated multitrophic aquaculture (IMTA) scenarios. Herein, we investigated the clearance capacity of four ubiquitous Mediterranean sponges (Agelas oroides, Axinella cannabina, Chondrosia reniformis and Sarcotragus foetidus) against three microalgal substrates with different size/motility characteristics: the nanophytoplankton Nannochloropsis sp. (textasciitilde3.2 μm, nonmotile) and Isochrysis sp. (textasciitilde3.8 μm, motile), as well as the diatom Phaeodactylum tricornutum (textasciitilde21.7 μm, nonmotile). In vitro cleaning experiments were conducted using sponge explants in 1 L of natural seawater and applying different microalgal cell concentrations under light/dark conditions. The investigated sponges exhibited a wide range of retention efficiencies for the different phytoplankton cells, with the lowest average values found for A. cannabina (37%) and the highest for A. oroides (70%). The latter could filter up to 14.1 mL seawater per hour and gram of sponge wet weight, by retaining 100% of Isochrysis at a density of 105 cells mL−1, under darkness. Our results highlight differences in filtering capacity among sponge species and preferences for microalgal substrates with distinct size and motility traits. |
2021 |
Papadaki, Maria; Mandalakis, Manolis; Anastasiou, Thekla I; Pouli, Marina; Asderis, Michalis; Katharios, Pantelis; Papandroulakis, Nikos; Mylonas, Constantinos C Fish Physiology and Biochemistry, 47 (6), pp. 1777–1792, 2021, ISSN: 1573-5168. @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} } 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. |
Christidis, Georgios; Mandalakis, Manolis; Anastasiou, Thekla I; Tserpes, George; Peristeraki, Panagiota; Somarakis, Stylianos Keeping Lagocephalus sceleratus off the Table: Sources of Variation in the Quantity of TTX, TTX Analogues, and Risk of Tetrodotoxication Journal Article Toxins, 13 (12), pp. 896, 2021, ISSN: 2072-6651, (BIODIV). @article{christidis_keeping_2021b, title = {Keeping Lagocephalus sceleratus off the Table: Sources of Variation in the Quantity of TTX, TTX Analogues, and Risk of Tetrodotoxication}, author = {Georgios Christidis and Manolis Mandalakis and Thekla I Anastasiou and George Tserpes and Panagiota Peristeraki and Stylianos Somarakis}, url = {https://www.mdpi.com/2072-6651/13/12/896}, doi = {10.3390/toxins13120896}, issn = {2072-6651}, year = {2021}, date = {2021-12-01}, urldate = {2022-01-17}, journal = {Toxins}, volume = {13}, number = {12}, pages = {896}, abstract = {The invasion of the tetrodotoxin (TTX)-bearing silver-cheeked toadfish and potential poisoning due to its consumption (tetrodotoxication) threatens public safety in the Mediterranean Sea. In this study, TTX and TTX analogues of Lagocephalus sceleratus (Gmelin, 1789) were measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in fish collected off the island of Crete (Southern Mediterranean). We tested the synergistic effect of a suite of factors potentially affecting toxins’ levels and tetrodotoxication risk using general and generalized linear models, respectively. The type of tissue, geographic origin (Cretan Sea, Libyan Sea), sex, and fish maturity stage were significant predictors of toxin concentrations. Mean TTX was higher in gonads and lower in muscles, higher in the Libyan Sea and in female fish, and lower in juvenile (virgin) fish. The concentration of TTX was also significantly and positively correlated with the concentration of several TTX analogues (4-epiTTX, 4,9-anhydroTTX, 11-deoxyTTX, 5,11/6,11-dideoxyTTX, 5,6,11-trideoxyTTX, 11-norTTX-6-ol). The analysis showed that fish originating from the Libyan Sea had significantly higher probability to cause tetrodotoxication in case of consumption. The variability explained by the models developed in this study was relatively low, indicating that toxin levels are hard to predict and the consumption of L. sceleratus should therefore be avoided.}, note = {BIODIV}, keywords = {}, pubstate = {published}, tppubtype = {article} } The invasion of the tetrodotoxin (TTX)-bearing silver-cheeked toadfish and potential poisoning due to its consumption (tetrodotoxication) threatens public safety in the Mediterranean Sea. In this study, TTX and TTX analogues of Lagocephalus sceleratus (Gmelin, 1789) were measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in fish collected off the island of Crete (Southern Mediterranean). We tested the synergistic effect of a suite of factors potentially affecting toxins’ levels and tetrodotoxication risk using general and generalized linear models, respectively. The type of tissue, geographic origin (Cretan Sea, Libyan Sea), sex, and fish maturity stage were significant predictors of toxin concentrations. Mean TTX was higher in gonads and lower in muscles, higher in the Libyan Sea and in female fish, and lower in juvenile (virgin) fish. The concentration of TTX was also significantly and positively correlated with the concentration of several TTX analogues (4-epiTTX, 4,9-anhydroTTX, 11-deoxyTTX, 5,11/6,11-dideoxyTTX, 5,6,11-trideoxyTTX, 11-norTTX-6-ol). The analysis showed that fish originating from the Libyan Sea had significantly higher probability to cause tetrodotoxication in case of consumption. The variability explained by the models developed in this study was relatively low, indicating that toxin levels are hard to predict and the consumption of L. sceleratus should therefore be avoided. |
Bravakos, Panos; Mandalakis, Manolis; Nomikou, Paraskevi; Anastasiou, Thekla I; Kristoffersen, Jon Bent; Stavroulaki, Melanthia; Kilias, Stephanos; Kotoulas, Georgios; Magoulas, Antonios; Polymenakou, Paraskevi N Genomic adaptation of Pseudomonas strains to acidity and antibiotics in hydrothermal vents at Kolumbo submarine volcano, Greece Journal Article Sci Rep, 11 (1), pp. 1336, 2021, ISSN: 2045-2322. @article{bravakos_genomic_2021, title = {Genomic adaptation of Pseudomonas strains to acidity and antibiotics in hydrothermal vents at Kolumbo submarine volcano, Greece}, author = {Panos Bravakos and Manolis Mandalakis and Paraskevi Nomikou and Thekla I Anastasiou and Jon Bent Kristoffersen and Melanthia Stavroulaki and Stephanos Kilias and Georgios Kotoulas and Antonios Magoulas and Paraskevi N Polymenakou}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/02/2021-Bravakos-SciReport-4.pdf http://www.nature.com/articles/s41598-020-79359-y}, doi = {10.1038/s41598-020-79359-y}, issn = {2045-2322}, year = {2021}, date = {2021-01-01}, urldate = {2021-02-02}, journal = {Sci Rep}, volume = {11}, number = {1}, pages = {1336}, abstract = {Abstract Although the rise of antibiotic and multidrug resistant bacteria is one of the biggest current threats to human health, our understanding of the mechanisms involved in antibiotic resistance selection remains scarce. We performed whole genome sequencing of 21 Pseudomonas strains, previously isolated from an active submarine volcano of Greece, the Kolumbo volcano. Our goal was to identify the genetic basis of the enhanced co-tolerance to antibiotics and acidity of these Pseudomonas strains. Pangenome analysis identified 10,908 Gene Clusters (GCs). It revealed that the numbers of phage-related GCs and sigma factors, which both provide the mechanisms of adaptation to environmental stressors, were much higher in the high tolerant Pseudomonas strains compared to the rest ones. All identified GCs of these strains were associated with antimicrobial and multidrug resistance. The present study provides strong evidence that the CO 2 -rich seawater of the volcano associated with low pH might be a reservoir of microorganisms carrying multidrug efflux-mediated systems and pumps. We, therefore, suggest further studies of other extreme environments (or ecosystems) and their associated physicochemical parameters (or factors) in the rise of antibiotic resistance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract Although the rise of antibiotic and multidrug resistant bacteria is one of the biggest current threats to human health, our understanding of the mechanisms involved in antibiotic resistance selection remains scarce. We performed whole genome sequencing of 21 Pseudomonas strains, previously isolated from an active submarine volcano of Greece, the Kolumbo volcano. Our goal was to identify the genetic basis of the enhanced co-tolerance to antibiotics and acidity of these Pseudomonas strains. Pangenome analysis identified 10,908 Gene Clusters (GCs). It revealed that the numbers of phage-related GCs and sigma factors, which both provide the mechanisms of adaptation to environmental stressors, were much higher in the high tolerant Pseudomonas strains compared to the rest ones. All identified GCs of these strains were associated with antimicrobial and multidrug resistance. The present study provides strong evidence that the CO 2 -rich seawater of the volcano associated with low pH might be a reservoir of microorganisms carrying multidrug efflux-mediated systems and pumps. We, therefore, suggest further studies of other extreme environments (or ecosystems) and their associated physicochemical parameters (or factors) in the rise of antibiotic resistance. |
Polymenakou, Paraskevi N; Nomikou, Paraskevi; Zafeiropoulos, Haris; Mandalakis, Manolis; Anastasiou, Thekla I; Kilias, Stephanos; Kyrpides, Nikos C; Kotoulas, Georgios; Magoulas, Antoniοs The Santorini Volcanic Complex as a Valuable Source of Enzymes for Bioenergy Journal Article Energies, 14 (5), pp. 1414, 2021, ISSN: 1996-1073. @article{polymenakou_santorini_2021, title = {The Santorini Volcanic Complex as a Valuable Source of Enzymes for Bioenergy}, author = {Paraskevi N Polymenakou and Paraskevi Nomikou and Haris Zafeiropoulos and Manolis Mandalakis and Thekla I Anastasiou and Stephanos Kilias and Nikos C Kyrpides and Georgios Kotoulas and Antoniοs Magoulas}, url = {https://www.mdpi.com/1996-1073/14/5/1414 https://imbbc.hcmr.gr/wp-content/uploads/2021/03/2021-Polymenakou-ENERGIES-24.pdf}, doi = {10.3390/en14051414}, issn = {1996-1073}, year = {2021}, date = {2021-01-01}, urldate = {2021-03-17}, journal = {Energies}, volume = {14}, number = {5}, pages = {1414}, abstract = {Marine microbial communities are an untapped reservoir of genetic and metabolic diversity and a valuable source for the discovery of new natural products of biotechnological interest. The newly discovered hydrothermal vent field of Santorini volcanic complex located in the Aegean Sea is gaining increasing interest for potential biotechnological exploitation. The conditions in these environments, i.e., high temperatures, low pH values and high concentration of heavy metals, often resemble harsh industrial settings. Thus, these environments may serve as pools of enzymes of enhanced catalytic properties that may provide benefits to biotechnology. Here, we screened 11 metagenomic libraries previously constructed from microbial mat samples covering the seafloor and the polymetallic chimneys of Kolumbo volcano as well as mat samples from Santorini caldera, to mine, in silico, genes associated with bioenergy applications. We particularly focused on genes encoding biomass hydrolysis enzymes such as cellulases, hemicellulases and lignin-degrading enzymes. A total of 10,417 genes were found for three specific groups of enzymes—i.e., the endoglucanases, the three different beta-glucosidases BGL, bglX and bglB, and the alpha-galactosidases melA, and rafA. Overall, we concluded that the Santorini–Kolumbo volcanic ecosystems constitute a significant resource of novel genes with potential applications in bioenergy that deserve further investigation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Marine microbial communities are an untapped reservoir of genetic and metabolic diversity and a valuable source for the discovery of new natural products of biotechnological interest. The newly discovered hydrothermal vent field of Santorini volcanic complex located in the Aegean Sea is gaining increasing interest for potential biotechnological exploitation. The conditions in these environments, i.e., high temperatures, low pH values and high concentration of heavy metals, often resemble harsh industrial settings. Thus, these environments may serve as pools of enzymes of enhanced catalytic properties that may provide benefits to biotechnology. Here, we screened 11 metagenomic libraries previously constructed from microbial mat samples covering the seafloor and the polymetallic chimneys of Kolumbo volcano as well as mat samples from Santorini caldera, to mine, in silico, genes associated with bioenergy applications. We particularly focused on genes encoding biomass hydrolysis enzymes such as cellulases, hemicellulases and lignin-degrading enzymes. A total of 10,417 genes were found for three specific groups of enzymes—i.e., the endoglucanases, the three different beta-glucosidases BGL, bglX and bglB, and the alpha-galactosidases melA, and rafA. Overall, we concluded that the Santorini–Kolumbo volcanic ecosystems constitute a significant resource of novel genes with potential applications in bioenergy that deserve further investigation. |
Mandalakis, Manolis; Anastasiou, Thekla I; Martou, Natalia; Keisaris, Sofoklis; Greveniotis, Vasileios; Katharios, Pantelis; Lazari, Diamanto; Krigas, Nikos; Antonopoulou, Efthimia Molecules, 26 (9), pp. 2731, 2021. @article{mandalakis_antibacterial_2021, title = {Antibacterial Effects of Essential Oils of Seven Medicinal-Aromatic Plants Against the Fish Pathogen Aeromonas veronii bv. sobria: To Blend or Not to Blend?}, author = {Manolis Mandalakis and Thekla I Anastasiou and Natalia Martou and Sofoklis Keisaris and Vasileios Greveniotis and Pantelis Katharios and Diamanto Lazari and Nikos Krigas and Efthimia Antonopoulou}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/05/2021-Mandalakis-molecules-37.pdf https://www.mdpi.com/1420-3049/26/9/2731}, doi = {10.3390/molecules26092731}, year = {2021}, date = {2021-01-01}, urldate = {2021-05-10}, journal = {Molecules}, volume = {26}, number = {9}, pages = {2731}, abstract = {Despite progress achieved, there is limited available information about the antibacterial activity of constituents of essential oils (EOs) from different medicinal-aromatic plants (MAPs) against fish pathogens and the complex interactions of blended EOs thereof. The present study aimed to investigate possible synergistic antimicrobial effects of EOs from seven Greek MAPs with strong potential against Aeromonas veronii bv. sobria, a fish pathogen associated with aquaculture disease outbreaks. The main objective was to evaluate whether blending of these EOs can lead to increased antimicrobial activity against the specific microorganism. A total of 127 combinations of EOs were prepared and their effect on A. veronii bv. sobria growth was tested in vitro. We examined both the inhibitory and bactericidal activities of the individual EOs and compared them to those of the blended EOs. The vast majority of the investigated combinations exhibited significant synergistic and additive effects, while antagonistic effects were evident only in a few cases, such as the mixtures containing EOs from rosemary, lemon balm and pennyroyal. The combination of EOs from Greek oregano and wild carrot, as well as the combinations of those two with Spanish oregano or savoury were the most promising ones. Overall, Greek oregano, savoury and Spanish oregano EOs were the most effective ones when applied either in pure form or blended with other EOs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite progress achieved, there is limited available information about the antibacterial activity of constituents of essential oils (EOs) from different medicinal-aromatic plants (MAPs) against fish pathogens and the complex interactions of blended EOs thereof. The present study aimed to investigate possible synergistic antimicrobial effects of EOs from seven Greek MAPs with strong potential against Aeromonas veronii bv. sobria, a fish pathogen associated with aquaculture disease outbreaks. The main objective was to evaluate whether blending of these EOs can lead to increased antimicrobial activity against the specific microorganism. A total of 127 combinations of EOs were prepared and their effect on A. veronii bv. sobria growth was tested in vitro. We examined both the inhibitory and bactericidal activities of the individual EOs and compared them to those of the blended EOs. The vast majority of the investigated combinations exhibited significant synergistic and additive effects, while antagonistic effects were evident only in a few cases, such as the mixtures containing EOs from rosemary, lemon balm and pennyroyal. The combination of EOs from Greek oregano and wild carrot, as well as the combinations of those two with Spanish oregano or savoury were the most promising ones. Overall, Greek oregano, savoury and Spanish oregano EOs were the most effective ones when applied either in pure form or blended with other EOs. |
Papadaki, Maria; Mandalakis, Manolis; Anastasiou, Thekla I; Pouli, Marina; Asderis, Michalis; Katharios, Pantelis; Papandroulakis, Nikos; Mylonas, Constantinos C Fish Physiology and Biochemistry, 47 (6), pp. 1777–1792, 2021, ISSN: 1573-5168. @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} } 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. |
Christidis, Georgios; Mandalakis, Manolis; Anastasiou, Thekla I; Tserpes, George; Peristeraki, Panagiota; Somarakis, Stylianos Keeping Lagocephalus sceleratus off the Table: Sources of Variation in the Quantity of TTX, TTX Analogues, and Risk of Tetrodotoxication Journal Article Toxins, 13 (12), pp. 896, 2021, ISSN: 2072-6651. @article{christidis_keeping_2021, title = {Keeping Lagocephalus sceleratus off the Table: Sources of Variation in the Quantity of TTX, TTX Analogues, and Risk of Tetrodotoxication}, author = {Georgios Christidis and Manolis Mandalakis and Thekla I Anastasiou and George Tserpes and Panagiota Peristeraki and Stylianos Somarakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/01/2021-Christidis-Toxins-87.pdf https://www.mdpi.com/2072-6651/13/12/896}, doi = {10.3390/toxins13120896}, issn = {2072-6651}, year = {2021}, date = {2021-01-01}, urldate = {2022-01-12}, journal = {Toxins}, volume = {13}, number = {12}, pages = {896}, abstract = {The invasion of the tetrodotoxin (TTX)-bearing silver-cheeked toadfish and potential poisoning due to its consumption (tetrodotoxication) threatens public safety in the Mediterranean Sea. In this study, TTX and TTX analogues of Lagocephalus sceleratus (Gmelin, 1789) were measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in fish collected off the island of Crete (Southern Mediterranean). We tested the synergistic effect of a suite of factors potentially affecting toxins’ levels and tetrodotoxication risk using general and generalized linear models, respectively. The type of tissue, geographic origin (Cretan Sea, Libyan Sea), sex, and fish maturity stage were significant predictors of toxin concentrations. Mean TTX was higher in gonads and lower in muscles, higher in the Libyan Sea and in female fish, and lower in juvenile (virgin) fish. The concentration of TTX was also significantly and positively correlated with the concentration of several TTX analogues (4-epiTTX, 4,9-anhydroTTX, 11-deoxyTTX, 5,11/6,11-dideoxyTTX, 5,6,11-trideoxyTTX, 11-norTTX-6-ol). The analysis showed that fish originating from the Libyan Sea had significantly higher probability to cause tetrodotoxication in case of consumption. The variability explained by the models developed in this study was relatively low, indicating that toxin levels are hard to predict and the consumption of L. sceleratus should therefore be avoided.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The invasion of the tetrodotoxin (TTX)-bearing silver-cheeked toadfish and potential poisoning due to its consumption (tetrodotoxication) threatens public safety in the Mediterranean Sea. In this study, TTX and TTX analogues of Lagocephalus sceleratus (Gmelin, 1789) were measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in fish collected off the island of Crete (Southern Mediterranean). We tested the synergistic effect of a suite of factors potentially affecting toxins’ levels and tetrodotoxication risk using general and generalized linear models, respectively. The type of tissue, geographic origin (Cretan Sea, Libyan Sea), sex, and fish maturity stage were significant predictors of toxin concentrations. Mean TTX was higher in gonads and lower in muscles, higher in the Libyan Sea and in female fish, and lower in juvenile (virgin) fish. The concentration of TTX was also significantly and positively correlated with the concentration of several TTX analogues (4-epiTTX, 4,9-anhydroTTX, 11-deoxyTTX, 5,11/6,11-dideoxyTTX, 5,6,11-trideoxyTTX, 11-norTTX-6-ol). The analysis showed that fish originating from the Libyan Sea had significantly higher probability to cause tetrodotoxication in case of consumption. The variability explained by the models developed in this study was relatively low, indicating that toxin levels are hard to predict and the consumption of L. sceleratus should therefore be avoided. |
2019 |
Anastasiou, Thekla I; Mandalakis, Manolis; Krigas, Nikos; Vézignol, Thomas; Lazari, Diamanto; Katharios, Pantelis; Dailianis, Thanos; Antonopoulou, Efthimia Molecules, 25 (1), pp. 148, 2019, ISSN: 1420-3049. @article{anastasiou_comparative_2019, title = {Comparative Evaluation of Essential Oils from Medicinal-Aromatic Plants of Greece: Chemical Composition, Antioxidant Capacity and Antimicrobial Activity against Bacterial Fish Pathogens}, author = {Thekla I Anastasiou and Manolis Mandalakis and Nikos Krigas and Thomas Vézignol and Diamanto Lazari and Pantelis Katharios and Thanos Dailianis and Efthimia Antonopoulou}, url = {https://www.mdpi.com/1420-3049/25/1/148}, doi = {10.3390/molecules25010148}, issn = {1420-3049}, year = {2019}, date = {2019-12-01}, urldate = {2020-08-09}, journal = {Molecules}, volume = {25}, number = {1}, pages = {148}, abstract = {The administration of antibiotics in aquaculture has raised concern about the impact of their overuse in marine ecosystems, seafood safety and consumers’ health. This “green consumerism” has forced researchers to find new alternatives against fish pathogens. The present study focused on 12 Mediterranean medicinal-aromatic plants as potential antimicrobials and antioxidant agents that could be used in fish aquaculture. In vitro assays showed that the essential oils (EOs) from all studied plants had anti-bacterial and antioxidant properties, with their efficacy being dependent on their chemical composition. More specifically, EOs rich in carvacrol, p-cymene and γ-terpinene exhibited not only the strongest inhibitory activity against the growth of bacterial pathogens (inhibitory concentration: 26–88 μg mL−1), but also the greatest total antioxidant capacity (ABTS: 2591–5879 μmole mL−1; CUPRAC: 931–2733 μmole mL−1). These compounds were mainly found in the EOs from Greek oregano (Origanum vulgare subsp. hirtum), Spanish oregano (Thymbra capitata) and savoury (Satureja thymbra) collected from cultivations in Greece. The specific EOs stand out as promising candidates for the treatment of bacterial diseases and oxidative stress in farmed fish. Further in vivo experiments are needed to fully understand the effects of EO dietary supplementation on fish farming processes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The administration of antibiotics in aquaculture has raised concern about the impact of their overuse in marine ecosystems, seafood safety and consumers’ health. This “green consumerism” has forced researchers to find new alternatives against fish pathogens. The present study focused on 12 Mediterranean medicinal-aromatic plants as potential antimicrobials and antioxidant agents that could be used in fish aquaculture. In vitro assays showed that the essential oils (EOs) from all studied plants had anti-bacterial and antioxidant properties, with their efficacy being dependent on their chemical composition. More specifically, EOs rich in carvacrol, p-cymene and γ-terpinene exhibited not only the strongest inhibitory activity against the growth of bacterial pathogens (inhibitory concentration: 26–88 μg mL−1), but also the greatest total antioxidant capacity (ABTS: 2591–5879 μmole mL−1; CUPRAC: 931–2733 μmole mL−1). These compounds were mainly found in the EOs from Greek oregano (Origanum vulgare subsp. hirtum), Spanish oregano (Thymbra capitata) and savoury (Satureja thymbra) collected from cultivations in Greece. The specific EOs stand out as promising candidates for the treatment of bacterial diseases and oxidative stress in farmed fish. Further in vivo experiments are needed to fully understand the effects of EO dietary supplementation on fish farming processes. |
2016 |
Anastasiou, T I; Chatzinikolaou, E; Mandalakis, M; Arvanitidis, C Imposex and organotin compounds in ports of the Mediterranean and the Atlantic: Is the story over? Journal Article Science of the Total Environment, 569-570 , pp. 1315–1329, 2016, ISSN: 00489697, (Publisher: Elsevier B.V.). @article{anastasiou_imposex_2016, title = {Imposex and organotin compounds in ports of the Mediterranean and the Atlantic: Is the story over?}, author = {T I Anastasiou and E Chatzinikolaou and M Mandalakis and C Arvanitidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978807299&doi=10.1016%2fj.scitotenv.2016.06.209&partnerID=40&md5=f0a46f0f9141ca86261409181b4d0d9b}, doi = {10.1016/j.scitotenv.2016.06.209}, issn = {00489697}, year = {2016}, date = {2016-01-01}, journal = {Science of the Total Environment}, volume = {569-570}, pages = {1315--1329}, abstract = {Organotin compounds are toxic substances released into the marine environment from antifouling paints. Sixty-two years following their first application and 9 years after the complete ban on their use as biocides in 2003 (EC No. 782/2003), their negative impact on mollusks was still evident, as illustrated by imposex (i.e. the masculinization of female gastropods). This phenomenon is widely used to investigate tributyltin (TBT) pollution, with Hexaplex trunculus and Nassarius nitidus being considered as sensitive bioindicators. H. trunculus specimens and sediment samples collected from the ports of Cagliari (Sardinia), El Kantaoui (Tunisia) and Olhão (Portugal), along with N. nitidus individuals from the port of Faro (Portugal), were used for the assessment of imposex intensity and organotin pollution in these areas. High imposex frequency and organotin concentrations (TBT, triphenyltin (TPhT) and their degradation products) were observed, especially in Sardinia, implying that these chemicals remain a significant pollution issue in the specific Mediterranean ports. Moreover, the highly significant relationship established between penis length of imposex-affected females H. trunculus and TBT/TPhT concentrations offers a rapid and nonsacrificial proxy model for assessing the impact of organotins in coastal environments. Finally, the complementary use of more than one TBT bioindicator is advised in order to obtain more accurate results in detailed monitoring studies of TBT pollution. © 2016 Elsevier B.V.}, note = {Publisher: Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Organotin compounds are toxic substances released into the marine environment from antifouling paints. Sixty-two years following their first application and 9 years after the complete ban on their use as biocides in 2003 (EC No. 782/2003), their negative impact on mollusks was still evident, as illustrated by imposex (i.e. the masculinization of female gastropods). This phenomenon is widely used to investigate tributyltin (TBT) pollution, with Hexaplex trunculus and Nassarius nitidus being considered as sensitive bioindicators. H. trunculus specimens and sediment samples collected from the ports of Cagliari (Sardinia), El Kantaoui (Tunisia) and Olhão (Portugal), along with N. nitidus individuals from the port of Faro (Portugal), were used for the assessment of imposex intensity and organotin pollution in these areas. High imposex frequency and organotin concentrations (TBT, triphenyltin (TPhT) and their degradation products) were observed, especially in Sardinia, implying that these chemicals remain a significant pollution issue in the specific Mediterranean ports. Moreover, the highly significant relationship established between penis length of imposex-affected females H. trunculus and TBT/TPhT concentrations offers a rapid and nonsacrificial proxy model for assessing the impact of organotins in coastal environments. Finally, the complementary use of more than one TBT bioindicator is advised in order to obtain more accurate results in detailed monitoring studies of TBT pollution. © 2016 Elsevier B.V. |
2015 |
Anastasiou, T; Chatzinikolaou, E; Mandalakis, M; Arvanitidis, C Imposex status and organotin concentrations in Hexaplex trunculus (Linnaeus, 1758) from the port of Cagliari (Sardinia) Inproceedings 11th Panhellenic Symposium on Oceanography and Fisheries, Mytilene, Greece, 2015. @inproceedings{anastasiou_imposex_2015, title = {Imposex status and organotin concentrations in Hexaplex trunculus (Linnaeus, 1758) from the port of Cagliari (Sardinia)}, author = {T Anastasiou and E Chatzinikolaou and M Mandalakis and C Arvanitidis}, year = {2015}, date = {2015-01-01}, booktitle = {11th Panhellenic Symposium on Oceanography and Fisheries}, address = {Mytilene, Greece}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |