FishesPub Date : 2024-07-08DOI: 10.3390/fishes9070269
Yucai Pan, Gefeng Xu, Tianqing Huang, W. Gu, Enhui Liu, Gaochao Wang
{"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}
FishesPub Date : 2024-07-08DOI: 10.3390/fishes9070270
Aylin Ulman, Cat A. Gordon, Ali R. Hood, Melanie Warren, Daniel Pauly
{"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}
FishesPub Date : 2024-07-05DOI: 10.3390/fishes9070265
Xiaojian Lai, Shuai Peng, Zhaoren Bai, Le Cao, Huixuan Huang, Yonghua Jiang, Yilei Wang
{"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}
FishesPub Date : 2024-07-05DOI: 10.3390/fishes9070268
A. A. Calderon-Garcia, Mercedes Sánchez-Barba, V. González-Núñez
{"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}
FishesPub Date : 2024-07-05DOI: 10.3390/fishes9070267
Xianpeng Huang, Z. Hao, J. Mao, Luo Wang, Xubo Wang, Ying Tian
{"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}
FishesPub Date : 2024-07-05DOI: 10.3390/fishes9070266
Yiying Jiang, Lei Huang, Yang Liu, Shuang Wang
{"title":"Impact of Digital Development and Technology Innovation on the Marine Fishery Economy Quality","authors":"Yiying Jiang, Lei Huang, Yang Liu, Shuang Wang","doi":"10.3390/fishes9070266","DOIUrl":"https://doi.org/10.3390/fishes9070266","url":null,"abstract":"The digital economy plays an important role in promoting the high quality and sustainable development of the marine fishery economy. Based on the panel data of the digital economy and marine fishery development from 2011 to 2022, we firstly adopted the entropy method to comprehensively evaluate the economy quality level of the digital economy and marine fishing. Secondly, we constructed a two-way fixed effect model to empirically analyze the impact of digital economy development on the marine fishery economy quality and the mediating role of marine green science and technology innovation, and further explored the regional heterogeneity of the digital economy on the marine fishery economy quality. Several findings emerge. The digital economy and the marine fishery economy quality level was relatively low and showed a fluctuating increase. The development of the digital economy can significantly improve the economy quality of marine fishing, and the conclusion was still valid after considering a series of robustness tests. The digital economy can drive the development quality of the marine fishery economy through marine green technology innovation. This paper proposes fostering the advancement of digital technology in the marine fishery sector, to effectively harness the innovation-driven potential of the digital economy, so as to facilitate the harmonious development of both the marine and digital economies.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":" 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674148","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}
FishesPub Date : 2024-07-04DOI: 10.3390/fishes9070263
Botao Zhong, Huaihua Yu, Shengming Han, Weiwei Song, Zhiming Ren, Chunlin Wang, C. Mu
{"title":"Functional Study on the BMP Signaling Pathway in the Molting of Scylla paramamosain","authors":"Botao Zhong, Huaihua Yu, Shengming Han, Weiwei Song, Zhiming Ren, Chunlin Wang, C. Mu","doi":"10.3390/fishes9070263","DOIUrl":"https://doi.org/10.3390/fishes9070263","url":null,"abstract":"In this study, we added LDN-193189 2HCL to inhibit the BMP signaling pathway in Scylla paramamosain and then explored the function of this pathway in molting through the changes in the growth performance and molt-related gene expression. The study findings indicated that the expression of ACVR1, BMPRIB, and Smad1 in Scylla paramamosain was suppressed when the LDN-193189 2HCL concentration in the culture water was 2 µm/L. Subsequently, following a 30-day experiment, there was a significant reduction in the molting frequency, growth rate, and body size of the S. paramamosain larvae. An analysis of the BMP pathway gene expression during the molting phase revealed that the BMP2, BMPR2, and Smad1 genes displayed cyclic expression patterns, while ACVR1, BMP7, and BMPRIB maintained consistent expression levels throughout the molting cycle. Additionally, the expression levels of BMP2, BMPR2, and Smad1 in the inhibition group were significantly lower compared to those in the control group. Furthermore, the inhibition of the BMP pathway led to an increase in the expression of MIH during the intermolt period and a decrease in the expression of EcR during the premolt period. These findings demonstrate that the BMP signaling pathway affects the molting of Scylla paramamosain juvenile crabs by influencing the expression of the critical genes MIH and ECR during molting, offering valuable data for functional research on the BMP signaling pathway in crustaceans.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141679170","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}
FishesPub Date : 2024-07-04DOI: 10.3390/fishes9070262
Pengcheng Li, Wan Chen, Kun Wang, Binduo Xu, Chongliang Zhang, Yu-peng Ji, Yiping Ren, Ying Xue
{"title":"Spatiotemporal Variations in Trophic Diversity of Fish Communities in a Marine Bay Ecosystem Based on Stable Isotope Analysis","authors":"Pengcheng Li, Wan Chen, Kun Wang, Binduo Xu, Chongliang Zhang, Yu-peng Ji, Yiping Ren, Ying Xue","doi":"10.3390/fishes9070262","DOIUrl":"https://doi.org/10.3390/fishes9070262","url":null,"abstract":"Climate change has led to significant fluctuations in marine ecosystems. As a component of the food web, the trophic diversity and spatiotemporal changes of fish communities are crucial for understanding ecosystems. In recent years, stable isotope analysis has been increasingly used as a comprehensive tool for quantitative assessment of trophic diversity to explore spatiotemporal variations in fish community diversity. This study is based on carbon (δ13C) and nitrogen (δ15N) stable isotope analysis using different biomass-weighted isotope diversity indices, including isotopic divergence index (IDiv), isotopic dispersion index (IDis), isotopic evenness index (IEve), and isotopic uniqueness index (IUni). The overall results indicate that IDis, IEve, and IUni values of fish communities were relatively low, while IDiv was relatively high in the Haizhou Bay ecosystem. IDiv, IDis, IEve, and IUni were lower in autumn than in spring; IDiv and IDis were relatively higher in offshore waters, while IEve and IUni were relatively higher in inshore waters. The changes in species composition and intensive pelagic–benthic coupling in Haizhou Bay may lead to significant spatiotemporal variations in the trophic diversity of fish communities in the area. These findings highlight the importance of incorporating trophic relationships into ecosystem models, which will help to enhance our understanding of the complexity of the trophic structure of fish communities.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":" 115","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141680444","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}
FishesPub Date : 2024-07-03DOI: 10.3390/fishes9070259
Haiyan Xiong, Houguo Xu
{"title":"How Current Global Aqua-Nutrition Research Matches the New Industry and Market Demands","authors":"Haiyan Xiong, Houguo Xu","doi":"10.3390/fishes9070259","DOIUrl":"https://doi.org/10.3390/fishes9070259","url":null,"abstract":"As a result of decades of rapid development, aquaculture has become the largest contributor to human seafood consumption [...]","PeriodicalId":505604,"journal":{"name":"Fishes","volume":"11 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141681240","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}
FishesPub Date : 2024-07-03DOI: 10.3390/fishes9070260
Qin Ma, Mingzheng Li, Huanzhang Liu
{"title":"Population Genetics of the Endemic Hemiculterella wui (Wang, 1935) in the Poyang Lake Basin (China)","authors":"Qin Ma, Mingzheng Li, Huanzhang Liu","doi":"10.3390/fishes9070260","DOIUrl":"https://doi.org/10.3390/fishes9070260","url":null,"abstract":"The Yangtze River floodplain is an area with an extremely rich diversity of fish species. Poyang Lake, as an important part of this river–floodplain system, is a crucial habitat for the survival of fish. However, prolonged human activities, such as environmental pollution and hydroelectric development, have degraded the habitat in the Poyang Lake Basin, posing threats to fish populations. Understanding genetic diversity is crucial for maintaining fish populations and understanding their dynamics. The genetic diversity of Hemiculterella wui, an economically endemic species in China of subfamily Cultrinae (Cypriniformes: Cyprinidae), has been understudied. This study investigated the genetic diversity and structure of H. wui populations from the Ganjiang, Xinjiang, Fuhe, and Raohe rivers in the Poyang Lake Basin using mitochondrial Cytb gene analysis. Results showed high haplotype diversity but low nucleotide diversity in H. wui’s Cytb sequences. Analysis of molecular variance (AMOVA) showed no significant geographic genetic structure among populations. Haplotype network analysis revealed no clear geographical clustering. Neutrality tests and haplotype nucleotide mismatch distribution indicated that all populations had experienced expansion events. These findings suggest that H. wui in Poyang Lake does not show a distinct geographic structure. However, it is still necessary to monitor the genetic characteristics of H. wui to maintain the genetic diversity of fishes in Poyang Basin, considering the threat of habitat loss and fragmentation to the population.","PeriodicalId":505604,"journal":{"name":"Fishes","volume":" 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141681076","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}