Wild fish are preferred by consumers primarily for their superior sensorial qualities, including taste and texture. However, their limited availability often results in higher prices. Considering this, we explored the possibility of enhancing the quality of earthen pond aquaculture fish by transferring them to a near wild environment. This study investigated how rewilding time affects the physical properties, nutritional composition, and volatile profile of grass carp muscle. The results showed that compared to the 0M group, the crude protein content in grass carp muscle did not change significantly (p > 0.05) as the rewilding time increased to 6 months. Meanwhile, the significant increase in hardness and springiness (p < 0.05) indicated that the textural characteristics of muscle, which were key sensory and physical indices of muscle quality, were improved. Although the 6M group showed a 58.93% reduction in crude fat content compared to the 0M group, it retained the highest docosahexaenoic acid (DHA) content. Sensory evaluation demonstrated that as the rewilding time increased, the fishy and grassy odors of the rewilding grass carp diminished. Furthermore, cluster heatmaps and partial least squares discriminant analysis (PLS-DA) revealed that cultured grass carp and rewilding grass carp at three time points exhibited differences in various indicators. The variable importance in projection (VIP) showed that volatile flavor compounds (acetone, propionaldehyde-D, 1-penten-3-ol) and hardness were key factors in distinguishing between them. Therefore, extending the rewilding time can potentially enhance the acceptability of cultured grass carp by improving the physical properties, nutritional quality, and volatile profile of the muscle. This approach may provide a new pathway for fish aquaculture.
{"title":"Effects of Rewilding Aquaculture Time on Nutritional Quality and Flavor Characteristics of Grass Carp (Ctenopharyngodon idellus)","authors":"Qianyun Han, Jiajie Hu, Weicong Pan, Jin Yu, Xiaoguo Ying, Jinpeng Weng, Weiye Li, Xudong Weng","doi":"10.3390/fishes9070275","DOIUrl":"https://doi.org/10.3390/fishes9070275","url":null,"abstract":"Wild fish are preferred by consumers primarily for their superior sensorial qualities, including taste and texture. However, their limited availability often results in higher prices. Considering this, we explored the possibility of enhancing the quality of earthen pond aquaculture fish by transferring them to a near wild environment. This study investigated how rewilding time affects the physical properties, nutritional composition, and volatile profile of grass carp muscle. The results showed that compared to the 0M group, the crude protein content in grass carp muscle did not change significantly (p > 0.05) as the rewilding time increased to 6 months. Meanwhile, the significant increase in hardness and springiness (p < 0.05) indicated that the textural characteristics of muscle, which were key sensory and physical indices of muscle quality, were improved. Although the 6M group showed a 58.93% reduction in crude fat content compared to the 0M group, it retained the highest docosahexaenoic acid (DHA) content. Sensory evaluation demonstrated that as the rewilding time increased, the fishy and grassy odors of the rewilding grass carp diminished. Furthermore, cluster heatmaps and partial least squares discriminant analysis (PLS-DA) revealed that cultured grass carp and rewilding grass carp at three time points exhibited differences in various indicators. The variable importance in projection (VIP) showed that volatile flavor compounds (acetone, propionaldehyde-D, 1-penten-3-ol) and hardness were key factors in distinguishing between them. Therefore, extending the rewilding time can potentially enhance the acceptability of cultured grass carp by improving the physical properties, nutritional quality, and volatile profile of the muscle. This approach may provide a new pathway for fish aquaculture.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"136 39","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141656498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aquaculture chemotherapeutants used to control sea lice in finfish aquaculture can disperse into the marine habitat and have the potential to affect non-target species like crustaceans. Some of the compounds used (especially in Canada) include in-feed drugs such as emamectin benzoate (EMB), and ivermectin (IVER), as well as bath pesticides such as azamethiphos (AZA) and hydrogen peroxide (HP). Despite the paucity of data, crustacean life cycle stages appear to have varying sensitivities to these compounds. This data review sets out to examine the intraspecies variation in sensitivity within life stages for lobster (Homarus) and prawn (Pandalus) species. Despite limited information, it appears that prawn eggs, adults, and juveniles are less sensitive to AZA and EMB compared with larvae, whereas for lobster the opposite is true: adults and juveniles are more sensitive than larvae to AZA (there was insufficient data to assess EMB). For HP, the sensitivity of prawn eggs appears comparable to larvae, but hatching success data suggest that this important stage of development is less impacted than eggs themselves as indicated by one study. These differences are important considerations for toxicity threshold determination processes and risk assessments, which ideally are environmentally relevant, and highlight the need for more data.
用于控制有鳍鱼类养殖中的海虱的水产养殖化学治疗剂会扩散到海洋栖息地，并有可能影响甲壳类等非目标物种。使用的一些化合物（尤其是在加拿大）包括饲料药物，如苯甲酰甲胺磷（EMB）和伊维菌素（IVER），以及浴用杀虫剂，如唑虫酰胺（AZA）和过氧化氢（HP）。尽管数据很少，但甲壳动物的生命周期阶段似乎对这些化合物具有不同的敏感性。本数据综述旨在研究龙虾（Homarus）和对虾（Pandalus）物种各生命阶段内敏感性的种内差异。尽管信息有限，但与幼体相比，对虾卵、成体和幼体对 AZA 和 EMB 的敏感性似乎较低，而龙虾的情况恰恰相反：成体和幼体对 AZA 的敏感性高于幼体（没有足够数据评估 EMB）。就 HP 而言，对虾卵的敏感性似乎与幼体相当，但孵化成功率数据表明，正如一项研究表明的那样，这一重要发育阶段受到的影响小于卵本身。这些差异是毒性阈值确定过程和风险评估的重要考虑因素，理想情况下，毒性阈值确定过程和风险评估与环境相关，并强调需要更多数据。
{"title":"Data Review on the Variation in Sensitivity to Aquaculture Chemotherapeutants in Some Crustacean Life Stages","authors":"S. Marteinson, M. Kingsbury, D. Hamoutene","doi":"10.3390/fishes9070273","DOIUrl":"https://doi.org/10.3390/fishes9070273","url":null,"abstract":"Aquaculture chemotherapeutants used to control sea lice in finfish aquaculture can disperse into the marine habitat and have the potential to affect non-target species like crustaceans. Some of the compounds used (especially in Canada) include in-feed drugs such as emamectin benzoate (EMB), and ivermectin (IVER), as well as bath pesticides such as azamethiphos (AZA) and hydrogen peroxide (HP). Despite the paucity of data, crustacean life cycle stages appear to have varying sensitivities to these compounds. This data review sets out to examine the intraspecies variation in sensitivity within life stages for lobster (Homarus) and prawn (Pandalus) species. Despite limited information, it appears that prawn eggs, adults, and juveniles are less sensitive to AZA and EMB compared with larvae, whereas for lobster the opposite is true: adults and juveniles are more sensitive than larvae to AZA (there was insufficient data to assess EMB). For HP, the sensitivity of prawn eggs appears comparable to larvae, but hatching success data suggest that this important stage of development is less impacted than eggs themselves as indicated by one study. These differences are important considerations for toxicity threshold determination processes and risk assessments, which ideally are environmentally relevant, and highlight the need for more data.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"122 34","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicoleta-Alexandra Damir, V. Coatu, D. Danilov, L. Lazăr, A. Oros
This study presents an extensive evaluation of the contamination levels in fish, mollusks, water, and sediments in the Black Sea over eight years, from 2016 to 2023. The primary aim was to determine the concentrations and distribution patterns of heavy metals (HMs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other persistent organic pollutants (POPs) in fish, water, and sediments of the Black Sea, and their implications for marine ecosystem health and human safety. Data were collected through scientific cruises and the methodology involved systematic sampling across different regions of the Romanian Black Sea, followed by rigorous laboratory analyses to identify and quantify the presence of contaminants. The study also examined the temporal trends of these pollutants, providing insights into their sources, pathways, and persistence in the marine environment. Additionally, the research assessed the bioaccumulation of contaminants in various biota, offering a critical perspective on food safety and potential risks to human consumers. The findings revealed significant spatial insights, highlighting areas of concern that require immediate attention and action. Notably, industrial discharge, agricultural runoff, and historical pollution hotspots were identified as major sources of contamination. This research underscores the need for enhanced monitoring and regulatory frameworks to mitigate pollution sources and safeguard the Black Sea ecosystem, advocating for sustainable practices and effective management strategies to preserve marine resources in the Black Sea.
{"title":"From Waters to Fish: A Multi-Faceted Analysis of Contaminants’ Pollution Sources, Distribution Patterns, and Ecological and Human Health Consequences","authors":"Nicoleta-Alexandra Damir, V. Coatu, D. Danilov, L. Lazăr, A. Oros","doi":"10.3390/fishes9070274","DOIUrl":"https://doi.org/10.3390/fishes9070274","url":null,"abstract":"This study presents an extensive evaluation of the contamination levels in fish, mollusks, water, and sediments in the Black Sea over eight years, from 2016 to 2023. The primary aim was to determine the concentrations and distribution patterns of heavy metals (HMs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other persistent organic pollutants (POPs) in fish, water, and sediments of the Black Sea, and their implications for marine ecosystem health and human safety. Data were collected through scientific cruises and the methodology involved systematic sampling across different regions of the Romanian Black Sea, followed by rigorous laboratory analyses to identify and quantify the presence of contaminants. The study also examined the temporal trends of these pollutants, providing insights into their sources, pathways, and persistence in the marine environment. Additionally, the research assessed the bioaccumulation of contaminants in various biota, offering a critical perspective on food safety and potential risks to human consumers. The findings revealed significant spatial insights, highlighting areas of concern that require immediate attention and action. Notably, industrial discharge, agricultural runoff, and historical pollution hotspots were identified as major sources of contamination. This research underscores the need for enhanced monitoring and regulatory frameworks to mitigate pollution sources and safeguard the Black Sea ecosystem, advocating for sustainable practices and effective management strategies to preserve marine resources in the Black Sea.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"130 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141656620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cunhua Zhai, Yutao Li, Guanyu Zhu, Wenjie Peng, Qiuxu E, Ying Zhang, Bo Ma
The present study aimed to explore whether water flow velocity could affect the swimming ability and overall energy metabolism of wild Amur grayling (Thymallus grubii). Swimming performance was assessed by measuring critical swimming speed (Ucrit), burst speed (Uburst), and oxygen consumption rate (MO2) based on the stepped velocity test method. Our results showed that the absolute values of Ucrit and Uburst tended to increase with body length. In contrast, the relative values of Ucrit and Uburst tended to decrease and increase, respectively. MO2 in Amur grayling was elevated with increasing velocity, suggesting relatively high swimming efficiency. We also measured the biochemical indices related to energy metabolism. Lactate dehydrogenase, hexokinase, and pyruvate kinase activities significantly increased (p < 0.05). Hepatic glycogen, glucose, and muscle glycogen contents decreased with the increasing trend of velocity (p < 0.05), the lactic acid contents of the blood and muscles increased significantly with the increase in velocities (p < 0.05), and changes in creatine phosphate content showed no significant difference (p > 0.05). The results not only denote the relationship between body size and swimming speed but also show the effects of water flow velocity on energy metabolism in Amur grayling. The results provide basic data for the construction of fish passage.
{"title":"The Effects of Water Flow Speed on Swimming Capacity and Energy Metabolism in Adult Amur Grayling (Thymallus grubii)","authors":"Cunhua Zhai, Yutao Li, Guanyu Zhu, Wenjie Peng, Qiuxu E, Ying Zhang, Bo Ma","doi":"10.3390/fishes9070272","DOIUrl":"https://doi.org/10.3390/fishes9070272","url":null,"abstract":"The present study aimed to explore whether water flow velocity could affect the swimming ability and overall energy metabolism of wild Amur grayling (Thymallus grubii). Swimming performance was assessed by measuring critical swimming speed (Ucrit), burst speed (Uburst), and oxygen consumption rate (MO2) based on the stepped velocity test method. Our results showed that the absolute values of Ucrit and Uburst tended to increase with body length. In contrast, the relative values of Ucrit and Uburst tended to decrease and increase, respectively. MO2 in Amur grayling was elevated with increasing velocity, suggesting relatively high swimming efficiency. We also measured the biochemical indices related to energy metabolism. Lactate dehydrogenase, hexokinase, and pyruvate kinase activities significantly increased (p < 0.05). Hepatic glycogen, glucose, and muscle glycogen contents decreased with the increasing trend of velocity (p < 0.05), the lactic acid contents of the blood and muscles increased significantly with the increase in velocities (p < 0.05), and changes in creatine phosphate content showed no significant difference (p > 0.05). The results not only denote the relationship between body size and swimming speed but also show the effects of water flow velocity on energy metabolism in Amur grayling. The results provide basic data for the construction of fish passage.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"76 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141662930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Kempf, H. Windisch, K. Kunz, H. Pörtner, Felix C Mark, M. Lucassen
Background: This study was part of a larger comprehensive project (BIOACID) addressing the physiological resilience of Polar cod, Boreogadus saida, to ocean acidification and global warming and aimed to unravel underlying molecular mechanisms of the observed physiological responses. Methods: Fish were acclimated long-term to three CO2 concentrations comprising control conditions (390 ppm) and two projected climate scenarios (780 ppm and 1170 ppm). Each CO2 treatment was combined with four temperatures: 0, 3, 6, and 8 °C. Here, we focused on the hepatic transcriptomic profiles from these previously physiologically characterized fish. Results: Generally, we did not detect signs of a classical stress response. Consistent with functional observations, warming induced much stronger molecular responses compared to elevated PCO2, but an interaction between both factors existed to some extent. Gene ontology analysis revealed a strong response in lipid, amino acid, and protein metabolism. With increasing temperature, we observed a shift away from lipid metabolism, while carbohydrate metabolic pathways remained stable. Conclusions: Although we found Polar cod to be quite resilient to ocean acidification, temperature will remain a critical parameter for this valuable Arctic keystone species, and the question remains as to whether the observed acclimation strategies can be implemented in its natural habitat, especially when food supply is limited.
{"title":"Hepatic Transcriptomic Responsiveness of Polar Cod, Boreogadus saida, to Ocean Acidification and Warming","authors":"S. Kempf, H. Windisch, K. Kunz, H. Pörtner, Felix C Mark, M. Lucassen","doi":"10.3390/fishes9070271","DOIUrl":"https://doi.org/10.3390/fishes9070271","url":null,"abstract":"Background: This study was part of a larger comprehensive project (BIOACID) addressing the physiological resilience of Polar cod, Boreogadus saida, to ocean acidification and global warming and aimed to unravel underlying molecular mechanisms of the observed physiological responses. Methods: Fish were acclimated long-term to three CO2 concentrations comprising control conditions (390 ppm) and two projected climate scenarios (780 ppm and 1170 ppm). Each CO2 treatment was combined with four temperatures: 0, 3, 6, and 8 °C. Here, we focused on the hepatic transcriptomic profiles from these previously physiologically characterized fish. Results: Generally, we did not detect signs of a classical stress response. Consistent with functional observations, warming induced much stronger molecular responses compared to elevated PCO2, but an interaction between both factors existed to some extent. Gene ontology analysis revealed a strong response in lipid, amino acid, and protein metabolism. With increasing temperature, we observed a shift away from lipid metabolism, while carbohydrate metabolic pathways remained stable. Conclusions: Although we found Polar cod to be quite resilient to ocean acidification, temperature will remain a critical parameter for this valuable Arctic keystone species, and the question remains as to whether the observed acclimation strategies can be implemented in its natural habitat, especially when food supply is limited.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"34 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141659333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yucai Pan, Gefeng Xu, Tianqing Huang, W. Gu, Enhui Liu, Gaochao Wang
The objective of this study was to investigate the effects of salmon gonadotropin releasing hormone analog (S-GnRH-A) and human chorionic gonadotropin (HCG) on the serum levels of gonadotropins (GtHs) and sex steroid hormones in Manchurian trout during sexual maturity. Females in the treatment group were injected with 20 µg/kg S-GnRH-A and 400 IU/kg HCG, whilst males were injected with half the amount. Blood samples were collected at 0, 5, 10, and 20 days post injection (dpi). The results showed an increase in female follicle-stimulating hormone (FSH) levels in the treatment group at 5 dpi, and from 5 dpi onwards, a difference was observed between the groups, with higher FSH levels in the treatment group compared to the control group. In males, FSH levels showed group differences at only 5 dpi (p < 0.05) and were higher in the treatment group. In females, luteinizing hormone (LH) peaked at 10 dpi in the treatment group, and there were differences between the two groups at 10 dpi and 20 dpi. In males, LH was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05). In females, estradiol (E2) was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05), whereas in males, the difference between the two groups was only observed at 5 dpi (p < 0.05). The female testosterone (T) level in the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), while T levels were significantly higher in the male treatment group than in the control group at 5 dpi (p < 0.05). The level of 17α–hydroxyprogesterone (17α-OHP) in the females of the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), and 17α-OHP levels were significantly higher in the male treatment group than in the control group at 10 and 20 dpi (p < 0.05). The fish were successfully spawned after S-GnRH-A and HCG injections, and brood amount, fertilization rate, and hatching rate were significantly increased (p < 0.05). This study provides a framework for a better understanding of the mechanisms of exogenous hormone-mediated control of reproduction in Manchurian trout.
{"title":"Effects of Exogenous Hormones on Spawning Performances, Serum Gonadotropin and Sex Steroid Hormone in Manchurian Trout (Brachymystax lenok) during Sexual Maturation","authors":"Yucai Pan, Gefeng Xu, Tianqing Huang, W. Gu, Enhui Liu, Gaochao Wang","doi":"10.3390/fishes9070269","DOIUrl":"https://doi.org/10.3390/fishes9070269","url":null,"abstract":"The objective of this study was to investigate the effects of salmon gonadotropin releasing hormone analog (S-GnRH-A) and human chorionic gonadotropin (HCG) on the serum levels of gonadotropins (GtHs) and sex steroid hormones in Manchurian trout during sexual maturity. Females in the treatment group were injected with 20 µg/kg S-GnRH-A and 400 IU/kg HCG, whilst males were injected with half the amount. Blood samples were collected at 0, 5, 10, and 20 days post injection (dpi). The results showed an increase in female follicle-stimulating hormone (FSH) levels in the treatment group at 5 dpi, and from 5 dpi onwards, a difference was observed between the groups, with higher FSH levels in the treatment group compared to the control group. In males, FSH levels showed group differences at only 5 dpi (p < 0.05) and were higher in the treatment group. In females, luteinizing hormone (LH) peaked at 10 dpi in the treatment group, and there were differences between the two groups at 10 dpi and 20 dpi. In males, LH was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05). In females, estradiol (E2) was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05), whereas in males, the difference between the two groups was only observed at 5 dpi (p < 0.05). The female testosterone (T) level in the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), while T levels were significantly higher in the male treatment group than in the control group at 5 dpi (p < 0.05). The level of 17α–hydroxyprogesterone (17α-OHP) in the females of the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), and 17α-OHP levels were significantly higher in the male treatment group than in the control group at 10 and 20 dpi (p < 0.05). The fish were successfully spawned after S-GnRH-A and HCG injections, and brood amount, fertilization rate, and hatching rate were significantly increased (p < 0.05). This study provides a framework for a better understanding of the mechanisms of exogenous hormone-mediated control of reproduction in Manchurian trout.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"119 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aylin Ulman, Cat A. Gordon, Ali R. Hood, Melanie Warren, Daniel Pauly
This study presents new records of three Critically Endangered angel shark species (Family: Squatinidae) occurring in the Eastern Mediterranean—Smoothback Angelshark S. oculata Bonaye, 1840, Sawback Angelshark S. aculeata Cuvier, 1829, and Angelshark S. squatina (Linnaeus, 1758). The supporting data serves to highlight three potential Critical Angel Shark Areas (CASAs) in Türkiye: Fethiye Bay, Çanakkale Strait (i.e., Dardanelles), and Antalya Bay. These data also demonstrate that female S. oculata may mature at a smaller size than prior published estimates of length at first maturity. This new dataset provides details of 23 S. squatina specimens, 52 S. oculata specimens, and 5 S. aculeata specimens, totalling 80 recent angel shark specimens found in Turkish waters mostly sent to us from small-scale fishers who had incidentally caught angel sharks. Also presented are four capture-induced parturition events in Turkish waters onboard fishing vessels, thus providing details on internal yolk sacs, reproductive habitats, and indications of spawning season. Our dataset presented here spans from 2018 to 2023 and suggests that mature adults of S. squatina and S. oculata still occur in Turkish waters, in Fethiye Bay and Çanakkale, respectively. Due to elevated chances of fishers encountering Critically Endangered angel sharks in Türkiye, we suggest that fishers are trained in handling and safe-release methods, to ensure reduced incidents of capture-induced parturition, and improved post-release survival. This study demonstrates that bottom set nets set by small-scale fishers pose less risk to mortality for angel sharks as they are almost always encountered alive after a usual 12 h soak time, suggesting that bottom trawling in critical habitats should be better regulated (or phased out) to help improve national angel shark conservation initiatives.
本研究提供了出现在东地中海的三个极度濒危天使鲨物种（科：鳞鲨科）的新记录--平滑天使鲨（S. oculata Bonaye, 1840）、锯背天使鲨（S. aculeata Cuvier, 1829）和天使鲨（S. squatina (Linnaeus, 1758)）。佐证数据突出了土耳其三个潜在的天使鲨关键区域 (CASA)：费特希耶湾、恰纳卡莱海峡（即达达尼尔海峡）和安塔利亚湾。这些数据还表明，雌性 S. oculata 的成熟体型可能小于之前公布的初熟体长估计值。这个新的数据集提供了23个S. squatina标本、52个S. oculata标本和5个S. aculeata标本的详细信息，总共80个最近在土耳其水域发现的天使鲨标本，大部分是由偶然捕获天使鲨的小型渔民寄给我们的。此外，还介绍了在土耳其水域渔船上的四次捕获诱发的产仔事件，从而提供了内部卵黄囊、生殖栖息地和产卵季节指示的详细信息。我们在此提供的数据集时间跨度为 2018 年至 2023 年，表明在土耳其水域（分别位于费特希耶湾和恰纳卡莱）仍有 S. squatina 和 S. oculata 的成熟成鱼。由于渔民在土耳其遇到极度濒危的天使鲨的几率增加，我们建议对渔民进行处理和安全释放方法的培训，以确保减少捕获引起的产仔事件，并提高释放后的存活率。这项研究表明，由小规模渔民设置的底层定置网对天使鲨造成的死亡风险较小，因为天使鲨在经过通常的 12 小时浸泡时间后几乎都是活的，这表明在关键栖息地的底层拖网捕捞应得到更好的监管（或逐步淘汰），以帮助改善国家的天使鲨保护措施。
{"title":"Identifying Potential Critical Angel Shark Areas in Türkiye, Eastern Mediterranean Based on New Records of Squatina spp. Identified through Fisher Engagement","authors":"Aylin Ulman, Cat A. Gordon, Ali R. Hood, Melanie Warren, Daniel Pauly","doi":"10.3390/fishes9070270","DOIUrl":"https://doi.org/10.3390/fishes9070270","url":null,"abstract":"This study presents new records of three Critically Endangered angel shark species (Family: Squatinidae) occurring in the Eastern Mediterranean—Smoothback Angelshark S. oculata Bonaye, 1840, Sawback Angelshark S. aculeata Cuvier, 1829, and Angelshark S. squatina (Linnaeus, 1758). The supporting data serves to highlight three potential Critical Angel Shark Areas (CASAs) in Türkiye: Fethiye Bay, Çanakkale Strait (i.e., Dardanelles), and Antalya Bay. These data also demonstrate that female S. oculata may mature at a smaller size than prior published estimates of length at first maturity. This new dataset provides details of 23 S. squatina specimens, 52 S. oculata specimens, and 5 S. aculeata specimens, totalling 80 recent angel shark specimens found in Turkish waters mostly sent to us from small-scale fishers who had incidentally caught angel sharks. Also presented are four capture-induced parturition events in Turkish waters onboard fishing vessels, thus providing details on internal yolk sacs, reproductive habitats, and indications of spawning season. Our dataset presented here spans from 2018 to 2023 and suggests that mature adults of S. squatina and S. oculata still occur in Turkish waters, in Fethiye Bay and Çanakkale, respectively. Due to elevated chances of fishers encountering Critically Endangered angel sharks in Türkiye, we suggest that fishers are trained in handling and safe-release methods, to ensure reduced incidents of capture-induced parturition, and improved post-release survival. This study demonstrates that bottom set nets set by small-scale fishers pose less risk to mortality for angel sharks as they are almost always encountered alive after a usual 12 h soak time, suggesting that bottom trawling in critical habitats should be better regulated (or phased out) to help improve national angel shark conservation initiatives.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"109 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaojian Lai, Shuai Peng, Zhaoren Bai, Le Cao, Huixuan Huang, Yonghua Jiang, Yilei Wang
The feedback regulatory effects of estrogen (E2) and androgen (T) on the gonadotropin-releasing hormone (GnRH) and gonadotropin (GtH) within the brain–pituitary–gonad (BPG) axis in eels with undeveloped ovaries were investigated through in vivo studies. However, the regulatory role of the BPG axis only became apparent during ovary development in the migratory stage. To further elucidate the direct feedback regulation of the BPG axis, female Anguilla japonica underwent artificial induction of vitellogenesis, and the regulation of BPG axis tissues by GtH (human chorionic gonadotropin, hCG), E2, and T was explored through in vitro exposure. The mRNA expression levels of GnRH (mGnRH), GtH (fshb and lhb), and steroid biosynthesis enzymes (cyp11a1, hsd3b, cyp17a1, and cyp17a2) in the diencephalon, pituitary, and ovary, respectively, were determined. The results showed that the expression level of mGnRH in the diencephalon was significantly downregulated by 0.1 IU/mL hCG but upregulated by both 1 nM E2 and higher concentrations of T, suggesting a direct positive feedback regulation of E2 on mGnRH. In the pituitary, the expression levels of fshb and lhb were upregulated by E2, while fshb was suppressed by T. In the ovaries, the expression of cyp11a1 and hsd3b was upregulated by 1 nM E2, whereas T exposure resulted in an opposite effect. Cyp17a1 mRNA levels did not differ significantly with E2 treatment but were upregulated by 1 nM T. These findings suggest that low concentrations of E2 exhibited positive feedback regulation on all three levels (diencephalon, pituitary, and ovary) of the BPG axis, while T showed weaker and differential feedback regulation in BPG axis tissues. Overall, this study’s results revealed the direct feedback regulation of hCG, E2, and T on the BPG axis in eels, a phylogenetic base of teleosts.
通过体内研究，探讨了雌激素（E2）和雄激素（T）对未发育卵巢的鳗鱼脑-垂体-性腺（BPG）轴中促性腺激素释放激素（GnRH）和促性腺激素（GtH）的反馈调节作用。然而，BPG轴的调控作用仅在卵巢发育的洄游阶段才变得明显。为了进一步阐明BPG轴的直接反馈调控，雌性鳗鲡接受了卵黄发生的人工诱导，并通过体外暴露探讨了GtH（人绒毛膜促性腺激素，hCG）、E2和T对BPG轴组织的调控。分别测定了GnRH（mGnRH）、GtH（fshb和lhb）和类固醇生物合成酶（cyp11a1、hsd3b、cyp17a1和cyp17a2）在间脑、垂体和卵巢中的mRNA表达水平。结果显示，mGnRH在间脑中的表达水平在0.1 IU/mL hCG的作用下显著下调，但在1 nM E2和较高浓度T的作用下均上调，这表明E2对mGnRH有直接的正反馈调节作用。在垂体中，E2会上调fshb和lhb的表达水平，而T则会抑制fshb的表达。这些研究结果表明，低浓度的 E2 对 BPG 轴的所有三个水平（间脑、垂体和卵巢）都有正反馈调节作用，而 T 对 BPG 轴组织的反馈调节作用较弱，且存在差异。总之，该研究结果揭示了 hCG、E2 和 T 对鳗鲡 BPG 轴的直接反馈调节作用。
{"title":"Direct Feedback Regulation of E2, T, and hCG in the Brain–Pituitary–Gonad Axis of Japanese Eel (Anguilla japonica) during Artificial Maturation","authors":"Xiaojian Lai, Shuai Peng, Zhaoren Bai, Le Cao, Huixuan Huang, Yonghua Jiang, Yilei Wang","doi":"10.3390/fishes9070265","DOIUrl":"https://doi.org/10.3390/fishes9070265","url":null,"abstract":"The feedback regulatory effects of estrogen (E2) and androgen (T) on the gonadotropin-releasing hormone (GnRH) and gonadotropin (GtH) within the brain–pituitary–gonad (BPG) axis in eels with undeveloped ovaries were investigated through in vivo studies. However, the regulatory role of the BPG axis only became apparent during ovary development in the migratory stage. To further elucidate the direct feedback regulation of the BPG axis, female Anguilla japonica underwent artificial induction of vitellogenesis, and the regulation of BPG axis tissues by GtH (human chorionic gonadotropin, hCG), E2, and T was explored through in vitro exposure. The mRNA expression levels of GnRH (mGnRH), GtH (fshb and lhb), and steroid biosynthesis enzymes (cyp11a1, hsd3b, cyp17a1, and cyp17a2) in the diencephalon, pituitary, and ovary, respectively, were determined. The results showed that the expression level of mGnRH in the diencephalon was significantly downregulated by 0.1 IU/mL hCG but upregulated by both 1 nM E2 and higher concentrations of T, suggesting a direct positive feedback regulation of E2 on mGnRH. In the pituitary, the expression levels of fshb and lhb were upregulated by E2, while fshb was suppressed by T. In the ovaries, the expression of cyp11a1 and hsd3b was upregulated by 1 nM E2, whereas T exposure resulted in an opposite effect. Cyp17a1 mRNA levels did not differ significantly with E2 treatment but were upregulated by 1 nM T. These findings suggest that low concentrations of E2 exhibited positive feedback regulation on all three levels (diencephalon, pituitary, and ovary) of the BPG axis, while T showed weaker and differential feedback regulation in BPG axis tissues. Overall, this study’s results revealed the direct feedback regulation of hCG, E2, and T on the BPG axis in eels, a phylogenetic base of teleosts.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":" 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141675280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. A. Calderon-Garcia, Mercedes Sánchez-Barba, V. González-Núñez
Morphine, a drug of abuse used to treat moderate-to-severe pain, elicits its actions by binding to the opioid receptors. Cocaine is an example of a recreational drug that inhibits dopamine reuptake. The molecular effects of morphine and cocaine have been described in different specific brain regions. However, the systemic outcome of these drugs on the whole organism has not been fully addressed. The aim of this study is to analyse the global effects of morphine (10 μM) and cocaine (15 μM) in the expression of proteins related to the reward pathway. Zebrafish embryos were exposed to these drugs from 5 hpf (hours post-fertilisation) to 6 dpf (days post-fertilisation). Dopamine levels were determined by ELISA, and the expression of Fos proteins, Creb, its activated form p-Creb and tyrosine hydroxylase (Th) were examined by Western blot. Both drugs decreased Th levels at 72 hpf and 6 dpf and modified the expression of Fos family members, pCreb and Creb in a time-dependent manner. Morphine and cocaine exposure differentially modified dopamine levels in 72 hpf and 6 dpf zebrafish embryos. Our results indicate that drugs of abuse modify the expression of several proteins and molecules related to the activation of the reward pathway.
{"title":"Exposure of Zebrafish Embryos to Morphine and Cocaine Induces Changes in the Levels of Dopamine and of Proteins Related to the Reward Pathway","authors":"A. A. Calderon-Garcia, Mercedes Sánchez-Barba, V. González-Núñez","doi":"10.3390/fishes9070268","DOIUrl":"https://doi.org/10.3390/fishes9070268","url":null,"abstract":"Morphine, a drug of abuse used to treat moderate-to-severe pain, elicits its actions by binding to the opioid receptors. Cocaine is an example of a recreational drug that inhibits dopamine reuptake. The molecular effects of morphine and cocaine have been described in different specific brain regions. However, the systemic outcome of these drugs on the whole organism has not been fully addressed. The aim of this study is to analyse the global effects of morphine (10 μM) and cocaine (15 μM) in the expression of proteins related to the reward pathway. Zebrafish embryos were exposed to these drugs from 5 hpf (hours post-fertilisation) to 6 dpf (days post-fertilisation). Dopamine levels were determined by ELISA, and the expression of Fos proteins, Creb, its activated form p-Creb and tyrosine hydroxylase (Th) were examined by Western blot. Both drugs decreased Th levels at 72 hpf and 6 dpf and modified the expression of Fos family members, pCreb and Creb in a time-dependent manner. Morphine and cocaine exposure differentially modified dopamine levels in 72 hpf and 6 dpf zebrafish embryos. Our results indicate that drugs of abuse modify the expression of several proteins and molecules related to the activation of the reward pathway.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":" 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141673551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xianpeng Huang, Z. Hao, J. Mao, Luo Wang, Xubo Wang, Ying Tian
In this study, we employed geometric morphometrics (GMs) to analyze the shell shape differences among two mass-selected strains of bay scallops (red shell strain (RS) and black shell strain (BS)) and a control group (CG). The results revealed distinct shell shape differences corresponding to shell coloration, with the black shell strain displaying a more elliptical shell compared to the red shell strain. Additionally, the umbonal angle of the red shell strain was smaller than that of the black shell strain, indicating that the black shell strain had a more favorable jet direction that could enhance swimming capabilities. To evaluate the model’s performance in practical applications, leave-one-out cross-validation was carried out on the two shell strains and one control group. The results demonstrated discrimination accuracy rates of 67.44%, 47.62%, and 68.18% for the BS strain, RS strain, and CG, respectively. Similarly, for the right valves, the discrimination accuracy rates were 62.79%, 50.00%, and 75.00% for the BS strain, RS strain, and CG, respectively.
{"title":"Morphometric Analysis of Two Shell Color Strains of the Bay Scallop Argopecten irradians","authors":"Xianpeng Huang, Z. Hao, J. Mao, Luo Wang, Xubo Wang, Ying Tian","doi":"10.3390/fishes9070267","DOIUrl":"https://doi.org/10.3390/fishes9070267","url":null,"abstract":"In this study, we employed geometric morphometrics (GMs) to analyze the shell shape differences among two mass-selected strains of bay scallops (red shell strain (RS) and black shell strain (BS)) and a control group (CG). The results revealed distinct shell shape differences corresponding to shell coloration, with the black shell strain displaying a more elliptical shell compared to the red shell strain. Additionally, the umbonal angle of the red shell strain was smaller than that of the black shell strain, indicating that the black shell strain had a more favorable jet direction that could enhance swimming capabilities. To evaluate the model’s performance in practical applications, leave-one-out cross-validation was carried out on the two shell strains and one control group. The results demonstrated discrimination accuracy rates of 67.44%, 47.62%, and 68.18% for the BS strain, RS strain, and CG, respectively. Similarly, for the right valves, the discrimination accuracy rates were 62.79%, 50.00%, and 75.00% for the BS strain, RS strain, and CG, respectively.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":" 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141675696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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