E. E. Peele, C. Huveneers, Culum Brown, Connor R. Gervais, K. E. Yopak
Morphological differences in the peripheral (sensory) and central (brain) nervous system may confer sensory and/or behavioral variation in elasmobranchs, both across taxa and throughout ontogeny. Over the last century, sea surface temperatures have increased over 0.5 °C and are predicted to rise 1–4 °C by the year 2100, potentially affecting species’ physiological performance negatively. As the nervous system of fishes grows continually throughout their lives, it may be highly plastic in response to environmental changes. This study examined the effects of increased rearing temperature on nervous system development in Port Jackson sharks (Heterodontus portusjacksoni). Egg cases (n = 21) were collected from Gulf St. Vincent (Adelaide, SA) and placed into either ambient (17.6 °C) or 3 °C above ambient seawater conditions through hatching and reared for up to five months post-hatch. Relative volumes of the eyes and nose (olfactory rosette) were quantified using magnetic resonance imaging, and relative brain size and size of major brain regions were compared between the two treatment groups. The size of the olfactory bulbs and tegmentum varied significantly between the treatment groups, which suggest differences in primary, secondary, or tertiary sensory processing and/or motor functions at elevated temperatures. While studies on acute responses to environmental conditions cannot inform true adaptation across broad timescales, understanding the effects of increased temperature on the brain phenotype can aid in predicting how elasmobranchs may fare in response to changing ocean conditions.
外周（感觉）和中枢（大脑）神经系统的形态差异可能会导致鞘鳃亚纲动物在感觉和/或行为上的变异，这种变异既存在于不同类群之间，也存在于整个个体发育过程中。在过去的一个世纪中，海面温度上升了0.5 °C以上，预计到2100年将上升1-4 °C，这可能会对物种的生理表现产生负面影响。由于鱼类的神经系统在其一生中不断成长，因此在应对环境变化时可能具有很强的可塑性。本研究考察了饲养温度升高对杰克逊港鲨鱼（Heterodontus portusjacksoni）神经系统发育的影响。从圣文森特湾（南澳大利亚州阿德莱德市）收集的卵箱（n = 21）在孵化过程中被置于环境温度（17.6 °C）或高于环境温度 3 °C 的海水条件下，并在孵化后饲养长达五个月。利用磁共振成像对眼睛和鼻子（嗅栅）的相对体积进行了量化，并比较了两个处理组之间大脑的相对大小和主要脑区的大小。不同处理组的嗅球和脑桥的大小差异显著，这表明在高温条件下，初级、二级或三级感觉处理和/或运动功能存在差异。虽然对环境条件急性反应的研究无法为大时间尺度的真正适应提供信息，但了解温度升高对大脑表型的影响有助于预测鞘鳃亚纲动物如何应对不断变化的海洋条件。
{"title":"Effects of Increased Temperature on Brain and Sensory Development in the Port Jackson Shark (Heterodontus portusjacksoni)","authors":"E. E. Peele, C. Huveneers, Culum Brown, Connor R. Gervais, K. E. Yopak","doi":"10.3390/fishes8120611","DOIUrl":"https://doi.org/10.3390/fishes8120611","url":null,"abstract":"Morphological differences in the peripheral (sensory) and central (brain) nervous system may confer sensory and/or behavioral variation in elasmobranchs, both across taxa and throughout ontogeny. Over the last century, sea surface temperatures have increased over 0.5 °C and are predicted to rise 1–4 °C by the year 2100, potentially affecting species’ physiological performance negatively. As the nervous system of fishes grows continually throughout their lives, it may be highly plastic in response to environmental changes. This study examined the effects of increased rearing temperature on nervous system development in Port Jackson sharks (Heterodontus portusjacksoni). Egg cases (n = 21) were collected from Gulf St. Vincent (Adelaide, SA) and placed into either ambient (17.6 °C) or 3 °C above ambient seawater conditions through hatching and reared for up to five months post-hatch. Relative volumes of the eyes and nose (olfactory rosette) were quantified using magnetic resonance imaging, and relative brain size and size of major brain regions were compared between the two treatment groups. The size of the olfactory bulbs and tegmentum varied significantly between the treatment groups, which suggest differences in primary, secondary, or tertiary sensory processing and/or motor functions at elevated temperatures. While studies on acute responses to environmental conditions cannot inform true adaptation across broad timescales, understanding the effects of increased temperature on the brain phenotype can aid in predicting how elasmobranchs may fare in response to changing ocean conditions.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138965904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xin Cai, Yaxing Zhang, Bin Wang, Aijun Cui, Yan Jiang, Zhaojun Meng, Yuting Li, Yongjiang Xu
Leptin (Lep) plays a crucial role in controlling food intake and maintaining energy balance in mammals. While several studies have shown the presence of multiple leptin genes in teleosts, limited information is currently available on how sex steroid hormones regulate the expression of these genes in fish. In this study, we used two previously expressed and purified leptin proteins to incubate four tissues in vitro (hypothalamic-pituitary-gonadal axis and liver) and used the RT-qPCR method to detect the expression of genes related to growth and reproduction in tongue sole (Cynoglossus semilaevis). The results showed that both recombinant LepA and LepB proteins of tongue sole almost entirely suppressed the expression of genes related to growth and reproduction in the hypothalamic-pituitary-gonadal axis and liver, while LepB may have had a positive role on steroid synthesis in gonads. Further, a high concentration of LepA facilitated the expression of IGF-Ι in liver. At the same time, we utilized human leptin to incubate four tissues in vitro; although most of them had trends similar to those stimulated with tongue sole leptins, there were still some differences, indicating differences among leptin homologs between humans and fishes. To our knowledge, this is the first study to explore the function of tongue sole LepA and LepB within the hypothalamic-pituitary-gonadal axis and liver in vitro. Our results provide a valuable resource and foundation for future studies.
{"title":"Effects of Recombinant Leptin Proteins on the Expression of Key Genes in the HPG Axis and Liver of Tongue Sole In Vitro","authors":"Xin Cai, Yaxing Zhang, Bin Wang, Aijun Cui, Yan Jiang, Zhaojun Meng, Yuting Li, Yongjiang Xu","doi":"10.3390/fishes8120608","DOIUrl":"https://doi.org/10.3390/fishes8120608","url":null,"abstract":"Leptin (Lep) plays a crucial role in controlling food intake and maintaining energy balance in mammals. While several studies have shown the presence of multiple leptin genes in teleosts, limited information is currently available on how sex steroid hormones regulate the expression of these genes in fish. In this study, we used two previously expressed and purified leptin proteins to incubate four tissues in vitro (hypothalamic-pituitary-gonadal axis and liver) and used the RT-qPCR method to detect the expression of genes related to growth and reproduction in tongue sole (Cynoglossus semilaevis). The results showed that both recombinant LepA and LepB proteins of tongue sole almost entirely suppressed the expression of genes related to growth and reproduction in the hypothalamic-pituitary-gonadal axis and liver, while LepB may have had a positive role on steroid synthesis in gonads. Further, a high concentration of LepA facilitated the expression of IGF-Ι in liver. At the same time, we utilized human leptin to incubate four tissues in vitro; although most of them had trends similar to those stimulated with tongue sole leptins, there were still some differences, indicating differences among leptin homologs between humans and fishes. To our knowledge, this is the first study to explore the function of tongue sole LepA and LepB within the hypothalamic-pituitary-gonadal axis and liver in vitro. Our results provide a valuable resource and foundation for future studies.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138967418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lasse Lange Jensen, Thomas Bjørn, Andreas Hein Korsgaard, C. Pertoldi, Niels Madsen
Anthropogenic activities increase turbidity in coastal marine environments globally, and turbidity is particularly caused by eutrophication. Turbidity is a measurement of the scattering and absorption of light by suspended matter in water. An increase in turbidity influences visual predators and affects community structures and whole ecosystems. The three-spined stickleback (Gasterosteus aculeatus) is a widespread species in the northern hemispheric Pacific and Atlantic oceans. It is a visual predator and, therefore, a very well-suited species for studying the effects of increasing turbidity on foraging behaviour and activity. Sticklebacks used for this study were from an aquarium in the North Sea Oceanarium. They have been in the aquarium for around two months and were originally collected in a highly eutrophicated marine fjord system. They were individually placed in an observation aquarium, fed with krill, given 10 min to forage, and observed by video cameras. The video films were analysed to study stickleback predation behaviour. Experiments were repeated with four different turbidity treatments, ranging from a mean of 0.034 up to 10 NTU (nephelometric turbidity unit). Bentonite clay was used as a turbidity-increasing substance. A statistically significant difference in foraging behaviour and activity between the turbidity treatments was observed. The test subjects were found to lunge less for prey and had a higher feeding latency with increasing turbidity. Additionally, they were less active with increasing turbidity. The behavioural instability estimated as a variation in feeding latency increased with increasing turbidity but decreased at the highest turbidity value. Our study indicates an effect of turbidity-increasing events on the behaviour of the three-spined stickleback and potentially also other similar visual predators.
{"title":"Influence of Turbidity on Foraging Behaviour in Three-Spined Sticklebacks (Gasterosteus aculeatus)","authors":"Lasse Lange Jensen, Thomas Bjørn, Andreas Hein Korsgaard, C. Pertoldi, Niels Madsen","doi":"10.3390/fishes8120609","DOIUrl":"https://doi.org/10.3390/fishes8120609","url":null,"abstract":"Anthropogenic activities increase turbidity in coastal marine environments globally, and turbidity is particularly caused by eutrophication. Turbidity is a measurement of the scattering and absorption of light by suspended matter in water. An increase in turbidity influences visual predators and affects community structures and whole ecosystems. The three-spined stickleback (Gasterosteus aculeatus) is a widespread species in the northern hemispheric Pacific and Atlantic oceans. It is a visual predator and, therefore, a very well-suited species for studying the effects of increasing turbidity on foraging behaviour and activity. Sticklebacks used for this study were from an aquarium in the North Sea Oceanarium. They have been in the aquarium for around two months and were originally collected in a highly eutrophicated marine fjord system. They were individually placed in an observation aquarium, fed with krill, given 10 min to forage, and observed by video cameras. The video films were analysed to study stickleback predation behaviour. Experiments were repeated with four different turbidity treatments, ranging from a mean of 0.034 up to 10 NTU (nephelometric turbidity unit). Bentonite clay was used as a turbidity-increasing substance. A statistically significant difference in foraging behaviour and activity between the turbidity treatments was observed. The test subjects were found to lunge less for prey and had a higher feeding latency with increasing turbidity. Additionally, they were less active with increasing turbidity. The behavioural instability estimated as a variation in feeding latency increased with increasing turbidity but decreased at the highest turbidity value. Our study indicates an effect of turbidity-increasing events on the behaviour of the three-spined stickleback and potentially also other similar visual predators.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138967102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Imam Hasan, Francesco Gai, Simona Cirrincione, S. Rimoldi, Giulio Saroglia, G. Terova
The aquaculture industry is looking for sustainable alternatives to conventional fish meals in fish feed, and insect-based meals are proving to be a promising solution. These meals are nutritionally optimal as they have a high protein content and an ideal amino acid profile. However, the presence of chitin, a component of the insect exoskeleton in these meals presents both an opportunity and a challenge. Chitosan, a derivative of chitin, is known to improve the physiological functions of fish, including growth, immunity, and disease resistance. While chitin and its derivative chitosan offer several physiological benefits, their presence can affect the digestibility of feed in some fish species, making the inclusion of insect-based meals in aquafeeds complex. While studies suggest positive effects, some problems, such as reduced growth rates in certain species, emphasize the need for further research on chitin digestion in fish. Chitinase, an enzyme that breaks down chitin, is being investigated as a potential solution to improve the nutritional value of insect meals in aquafeed. This review provides a comprehensive analysis of the applications, benefits, and challenges of using chitinase in aquaculture, highlighting the enzyme’s role in improving feed digestibility, disease control, and environmental sustainability. Extensive research is required to fully understand the potential of chitinase enzymes in aquaculture and to optimize their applications in this dynamic field. Overall, this review provides insight into the evolving landscape of insect-based meals and the applications of chitinase enzymes within sustainable aquaculture practices.
{"title":"Chitinase and Insect Meal in Aquaculture Nutrition: A Comprehensive Overview of the Latest Achievements","authors":"Imam Hasan, Francesco Gai, Simona Cirrincione, S. Rimoldi, Giulio Saroglia, G. Terova","doi":"10.3390/fishes8120607","DOIUrl":"https://doi.org/10.3390/fishes8120607","url":null,"abstract":"The aquaculture industry is looking for sustainable alternatives to conventional fish meals in fish feed, and insect-based meals are proving to be a promising solution. These meals are nutritionally optimal as they have a high protein content and an ideal amino acid profile. However, the presence of chitin, a component of the insect exoskeleton in these meals presents both an opportunity and a challenge. Chitosan, a derivative of chitin, is known to improve the physiological functions of fish, including growth, immunity, and disease resistance. While chitin and its derivative chitosan offer several physiological benefits, their presence can affect the digestibility of feed in some fish species, making the inclusion of insect-based meals in aquafeeds complex. While studies suggest positive effects, some problems, such as reduced growth rates in certain species, emphasize the need for further research on chitin digestion in fish. Chitinase, an enzyme that breaks down chitin, is being investigated as a potential solution to improve the nutritional value of insect meals in aquafeed. This review provides a comprehensive analysis of the applications, benefits, and challenges of using chitinase in aquaculture, highlighting the enzyme’s role in improving feed digestibility, disease control, and environmental sustainability. Extensive research is required to fully understand the potential of chitinase enzymes in aquaculture and to optimize their applications in this dynamic field. Overall, this review provides insight into the evolving landscape of insect-based meals and the applications of chitinase enzymes within sustainable aquaculture practices.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139001537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Catch-per-unit-effort (CPUE) standardization in fisheries is a critical foundation for conducting stock assessment and fishery conservation. The Pacific sardine (Sardinops sagax) is one of the economically important fish species in the Northwest Pacific Ocean (NPO). Hence, the importance of choosing an appropriate CPUE standardization model cannot be overstated when it comes to achieving a precise relative abundance index for the efficient management of Pacific sardine fishery. This study’s main aim was to assess and compare the efficacy of three models, specifically the General Linear Model (GLM), the Generalized Linear Mixed Model (GLMM), and the spatio-temporal GLMM (VAST), in the CPUE standardization for Pacific sardine fishery in the NPO, with the ultimate goal of identifying the most appropriate model. An influence analysis was applied to analyze the impact of individual variables on the disparity among standardized and nominal CPUE, and the main explanatory variables influencing standardized CPUE were identified. A coefficient–distribution–influence (CDI) plot was generated to analyze the impact of the different models on the annual standardized CPUE. Additionally, a simulation testing framework was developed to evaluate the estimated accuracy of the three models. The results indicated that the standardized CPUE and the nominal CPUE exhibited similar trends between 2014 and 2021 for the three models. Compared to the GLM and the GLMM, the VAST demonstrates larger conditional R2 and smaller conditional AIC, indicating a better performance in standardizing the CPUE for Pacific sardines due to its consideration of spatial and temporal variations. The interaction terms within the three models exert significant influences on the annual standardized CPUE, necessitating their inclusion in the model construction. CDI plots indicate that the spatio-temporal influence of the VAST model exhibits a smaller variation trend, suggesting that the VAST is more robust when standardizing the CPUE for Pacific sardines. Simulation testing additionally demonstrated that the VAST model displays smaller model root mean squared error (RMSE) and bias, establishing it as the superior performer for standardizing CPUE. Our results provide a theoretical basis for the scientific management of Pacific sardines in the NPO and can be extended to CPUE standardization for other small pelagic fish species worldwide.
{"title":"Evaluation Performance of Three Standardization Models to Estimate Catch-per-Unit-Effort: A Case Study on Pacific Sardine (Sardinops sagax) in the Northwest Pacific Ocean","authors":"Yongchuang Shi, Haibin Han, Fenghua Tang, Shengmao Zhang, Wei Fan, Heng Zhang, Zuli Wu","doi":"10.3390/fishes8120606","DOIUrl":"https://doi.org/10.3390/fishes8120606","url":null,"abstract":"Catch-per-unit-effort (CPUE) standardization in fisheries is a critical foundation for conducting stock assessment and fishery conservation. The Pacific sardine (Sardinops sagax) is one of the economically important fish species in the Northwest Pacific Ocean (NPO). Hence, the importance of choosing an appropriate CPUE standardization model cannot be overstated when it comes to achieving a precise relative abundance index for the efficient management of Pacific sardine fishery. This study’s main aim was to assess and compare the efficacy of three models, specifically the General Linear Model (GLM), the Generalized Linear Mixed Model (GLMM), and the spatio-temporal GLMM (VAST), in the CPUE standardization for Pacific sardine fishery in the NPO, with the ultimate goal of identifying the most appropriate model. An influence analysis was applied to analyze the impact of individual variables on the disparity among standardized and nominal CPUE, and the main explanatory variables influencing standardized CPUE were identified. A coefficient–distribution–influence (CDI) plot was generated to analyze the impact of the different models on the annual standardized CPUE. Additionally, a simulation testing framework was developed to evaluate the estimated accuracy of the three models. The results indicated that the standardized CPUE and the nominal CPUE exhibited similar trends between 2014 and 2021 for the three models. Compared to the GLM and the GLMM, the VAST demonstrates larger conditional R2 and smaller conditional AIC, indicating a better performance in standardizing the CPUE for Pacific sardines due to its consideration of spatial and temporal variations. The interaction terms within the three models exert significant influences on the annual standardized CPUE, necessitating their inclusion in the model construction. CDI plots indicate that the spatio-temporal influence of the VAST model exhibits a smaller variation trend, suggesting that the VAST is more robust when standardizing the CPUE for Pacific sardines. Simulation testing additionally demonstrated that the VAST model displays smaller model root mean squared error (RMSE) and bias, establishing it as the superior performer for standardizing CPUE. Our results provide a theoretical basis for the scientific management of Pacific sardines in the NPO and can be extended to CPUE standardization for other small pelagic fish species worldwide.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138979038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xuehui Shi, Xinyi Tang, Yichao Zhang, Wenqi Wang, Siyong Qin, Qinghua Liu, Jie Mei
Seahorses are valuable species for their use in traditional Chinese medicine, as well as for the aquarium trade as ornamentals and curiosities. To balance market demand and reduce pressure on wild populations, many countries have undertaken commercial seahorse cultivation. Skeletal development plays a crucial role in fish fry culture, affecting external morphology, feeding, and movement. This study investigated the ontogeny allometry, timing, and progression of skeletal development in H. abdominalis from DAB (day after birth) 1 to DAB 100 under mass-scale captive breeding conditions in north China. The results of this study revealed the growth rate was significantly increased between DAB 30 and DAB 54. Allometry analysis revealed that in the early stage, the head, trunk, and tail demonstrated almost isometric growth. However, in the later stage, the head and trunk exhibited negative isometric growth, whereas the tail displayed positive isometric growth. Skeletal staining results showed that newborn seahorses do not have ossified bones until DAB 11 (SL 28.14 ± 2.94 mm). Ossification was primarily observed in the jaw region and the tubular nasal structure of the cranium, which indicated the importance of the early development of feeding organs. The initial formation of ossified vertebral columns was observed at DAB 13 (SL 26.48 ± 0.63 mm), with the complete ossification of all vertebrae occurring by DAB 45 (SL 54.87 ± 4.70 mm). Furthermore, the cranium, rings, and plates were all fully ossified by DAB 30. Ossification of the fins began at DAB 23 (SL 31.27 ± 4.05 mm). However, neither of them were fully ossified by DAB 100. The pelvic fin and the complete structure of the caudal fin were not observed, possibly because of caudal fin ray structure degeneration within the pouch. In addition, no skeletal deformities were observed in all the tested samples. The results of this study provide valuable information on the developmental biology of H. abdominalis, enriching our understanding of their growth and offering insights for optimizing fish fry breeding technologies.
海马是珍贵的物种，可用于传统中药，也可作为观赏品和奇珍异宝用于水族馆贸易。为了平衡市场需求，减少对野生种群的压力，许多国家都开展了商业海马养殖。骨骼发育在鱼苗养殖中起着至关重要的作用，影响着外部形态、摄食和运动。本研究调查了华北地区大规模人工繁殖条件下海马从出生后第1天（DAB）到第100天（DAB）的骨骼发育过程。研究结果表明，腹黑鱼在出生后第30天至第54天的生长速度明显加快。异体生长分析表明，在早期阶段，头部、躯干和尾部几乎呈等距生长。但在后期，头部和躯干呈现负等距生长，而尾部则呈现正等距生长。骨骼染色结果表明，新生海马在第 11 个 DAB 期（SL 28.14 ± 2.94 mm）前骨骼尚未骨化。骨化主要出现在下颌区域和头颅的管状鼻结构，这表明摄食器官的早期发育非常重要。在第 13 个 DAB 日（SL 26.48 ± 0.63 mm）观察到骨化椎柱的初步形成，到第 45 个 DAB 日（SL 54.87 ± 4.70 mm）所有椎骨完全骨化。此外，到第 30 个 DAB 日，颅骨、骨环和骨板均已完全骨化。鳍的骨化始于 DAB 23（SL 31.27 ± 4.05 mm）。然而，到第 100 个 DAB 日，它们都没有完全骨化。没有观察到骨盆鳍和尾鳍的完整结构，可能是因为尾鳍射线结构在袋内退化。此外，所有检测样本均未发现骨骼畸形。这项研究结果为腹黑鱼的发育生物学提供了宝贵的信息，丰富了我们对其生长的了解，并为优化鱼苗培育技术提供了启示。
{"title":"The Early Allometric Growth and Osteological Ontogeny of Pot-Bellied Seahorse (Hippocampus abdominalis, L. 1827) under Mass-Scale Captive Breeding Conditions in North China","authors":"Xuehui Shi, Xinyi Tang, Yichao Zhang, Wenqi Wang, Siyong Qin, Qinghua Liu, Jie Mei","doi":"10.3390/fishes8120604","DOIUrl":"https://doi.org/10.3390/fishes8120604","url":null,"abstract":"Seahorses are valuable species for their use in traditional Chinese medicine, as well as for the aquarium trade as ornamentals and curiosities. To balance market demand and reduce pressure on wild populations, many countries have undertaken commercial seahorse cultivation. Skeletal development plays a crucial role in fish fry culture, affecting external morphology, feeding, and movement. This study investigated the ontogeny allometry, timing, and progression of skeletal development in H. abdominalis from DAB (day after birth) 1 to DAB 100 under mass-scale captive breeding conditions in north China. The results of this study revealed the growth rate was significantly increased between DAB 30 and DAB 54. Allometry analysis revealed that in the early stage, the head, trunk, and tail demonstrated almost isometric growth. However, in the later stage, the head and trunk exhibited negative isometric growth, whereas the tail displayed positive isometric growth. Skeletal staining results showed that newborn seahorses do not have ossified bones until DAB 11 (SL 28.14 ± 2.94 mm). Ossification was primarily observed in the jaw region and the tubular nasal structure of the cranium, which indicated the importance of the early development of feeding organs. The initial formation of ossified vertebral columns was observed at DAB 13 (SL 26.48 ± 0.63 mm), with the complete ossification of all vertebrae occurring by DAB 45 (SL 54.87 ± 4.70 mm). Furthermore, the cranium, rings, and plates were all fully ossified by DAB 30. Ossification of the fins began at DAB 23 (SL 31.27 ± 4.05 mm). However, neither of them were fully ossified by DAB 100. The pelvic fin and the complete structure of the caudal fin were not observed, possibly because of caudal fin ray structure degeneration within the pouch. In addition, no skeletal deformities were observed in all the tested samples. The results of this study provide valuable information on the developmental biology of H. abdominalis, enriching our understanding of their growth and offering insights for optimizing fish fry breeding technologies.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiayang Li, Yu Guo, Xinye Zhao, Shengjie Zhou, Zhenhua Ma, Gang Yu, C. Qin, Xingqiang Wang
In this study, we sought to characterize the effect of water vibration frequency stress on crimson snapper (Lutjanus erythropterus) survival to determine an optimal transportation speed. To achieve this, we used a transport tank (25 cm × 17 cm × 16 cm) to simulate the transport process. After 8 h at five different vibration frequencies (D1 = 75 rpm, D2 = 105 rpm, D3 = 135 rpm, D4 = 165 rpm, and D5 = 195 rpm), the pH and dissolved oxygen (DO) levels in the tanks decreased; ammonia nitrogen levels (NH4-N) and temperature (T) increased with increasing density; and significant changes in oxidative stress biomarkers, digestive enzymes, and ATPase levels were observed in crimson snapper fry. The enzyme activity increased and reached the maximum value at 195 rpm. The experimental results suggested that during the actual transport, when using transport tanks, the length of the transport time was less than 8 h, and setting the vibration frequency for transportation at 135 rpm was more appropriate, that is, a speed of 50 km/h for transporting crimson snapper fry.
{"title":"The Effects of Vibration Frequency on Oxidative Stress, Digestive Enzymes and ATPases of Crimson Snapper (Lutjanus erythropterus) Fry during Transport","authors":"Jiayang Li, Yu Guo, Xinye Zhao, Shengjie Zhou, Zhenhua Ma, Gang Yu, C. Qin, Xingqiang Wang","doi":"10.3390/fishes8120603","DOIUrl":"https://doi.org/10.3390/fishes8120603","url":null,"abstract":"In this study, we sought to characterize the effect of water vibration frequency stress on crimson snapper (Lutjanus erythropterus) survival to determine an optimal transportation speed. To achieve this, we used a transport tank (25 cm × 17 cm × 16 cm) to simulate the transport process. After 8 h at five different vibration frequencies (D1 = 75 rpm, D2 = 105 rpm, D3 = 135 rpm, D4 = 165 rpm, and D5 = 195 rpm), the pH and dissolved oxygen (DO) levels in the tanks decreased; ammonia nitrogen levels (NH4-N) and temperature (T) increased with increasing density; and significant changes in oxidative stress biomarkers, digestive enzymes, and ATPase levels were observed in crimson snapper fry. The enzyme activity increased and reached the maximum value at 195 rpm. The experimental results suggested that during the actual transport, when using transport tanks, the length of the transport time was less than 8 h, and setting the vibration frequency for transportation at 135 rpm was more appropriate, that is, a speed of 50 km/h for transporting crimson snapper fry.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138589751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction: Xu et al. Effects of Replacing Dietary Fish Meal by Soybean Meal Co-Fermented Using Bacillus subtilis and Enterococcus faecium on Serum Antioxidant Indices and Gut Microbiota of Crucian Carp Carassius auratus. Fishes 2022, 7, 54","authors":"Qian Xu, Zheng Yang, Siyu Chen, Wenjuan Zhu, Siyuan Xiao, Jing Liu, Hongquan Wang, Shile Lan","doi":"10.3390/fishes8120601","DOIUrl":"https://doi.org/10.3390/fishes8120601","url":null,"abstract":"In the original publication [...]","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138593754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Comprehending the spatial distribution of human fishing endeavors holds significant importance in the context of monitoring fishery resources and implementing spatial management measures. To gain insights into the spatial arrangement of tuna longline activities within the exclusive economic zones of Tonga and their correlation with the marine environment, this study utilizes data from the Tonga Tuna Longline Fisheries spanning from 2002 to 2018. The data are employed to extract information about the spatial distribution of fishing efforts and coupled with 15 marine environmental variables covering both sea surface and subsurface conditions. This study employs boosted regression trees (BRT) and general additive models (GAM) to establish the non-linear relationships between the distribution of fishing effort and marine environmental factors. Furthermore, it examines and analyzes the ecological niche occupied by tuna longline vessels in high-sea environments. The outcomes of the factor analysis indicate that the most important factors influencing the fishing efforts of tuna longliners are the dissolved oxygen content at the sea surface and latitude. These two factors contribute significantly, accounting for 19.06% and 18.62% of the fishing efforts of vessels, respectively, followed by distance to ports, longitude, and dissolved oxygen at 100 m depth, contributing 10.77%, 7.07%, and 6.30%, respectively. The sea surface chlorophyll, ocean current at 100 m depth, and mixed layer depth contributed the least, 3.63%, 2.13%, and 1.72, respectively. In terms of space and time, tuna longliners are more likely to operate in the 18–22° S latitudinal and 172–178° W longitudinal region, and fishing efforts increased in the months from March to August. The spatial distribution of the fishing efforts modeled for fishing vessels in 2018 is predicted to have good spatial distribution with the actual fishing efforts of these vessels. This research aids in comprehending the environmental impacts resulting from shifts in the spatial distribution of tuna longline vessels, offering valuable insights for the effective management of tuna longline fisheries in Tonga.
{"title":"Environmental Factors Determine Tuna Fishing Vessels’ Behavior in Tonga","authors":"Siosaia Vaihola, Stuart Kininmonth","doi":"10.3390/fishes8120602","DOIUrl":"https://doi.org/10.3390/fishes8120602","url":null,"abstract":"Comprehending the spatial distribution of human fishing endeavors holds significant importance in the context of monitoring fishery resources and implementing spatial management measures. To gain insights into the spatial arrangement of tuna longline activities within the exclusive economic zones of Tonga and their correlation with the marine environment, this study utilizes data from the Tonga Tuna Longline Fisheries spanning from 2002 to 2018. The data are employed to extract information about the spatial distribution of fishing efforts and coupled with 15 marine environmental variables covering both sea surface and subsurface conditions. This study employs boosted regression trees (BRT) and general additive models (GAM) to establish the non-linear relationships between the distribution of fishing effort and marine environmental factors. Furthermore, it examines and analyzes the ecological niche occupied by tuna longline vessels in high-sea environments. The outcomes of the factor analysis indicate that the most important factors influencing the fishing efforts of tuna longliners are the dissolved oxygen content at the sea surface and latitude. These two factors contribute significantly, accounting for 19.06% and 18.62% of the fishing efforts of vessels, respectively, followed by distance to ports, longitude, and dissolved oxygen at 100 m depth, contributing 10.77%, 7.07%, and 6.30%, respectively. The sea surface chlorophyll, ocean current at 100 m depth, and mixed layer depth contributed the least, 3.63%, 2.13%, and 1.72, respectively. In terms of space and time, tuna longliners are more likely to operate in the 18–22° S latitudinal and 172–178° W longitudinal region, and fishing efforts increased in the months from March to August. The spatial distribution of the fishing efforts modeled for fishing vessels in 2018 is predicted to have good spatial distribution with the actual fishing efforts of these vessels. This research aids in comprehending the environmental impacts resulting from shifts in the spatial distribution of tuna longline vessels, offering valuable insights for the effective management of tuna longline fisheries in Tonga.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138592493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amanda Cohen-Sánchez, Antoni Gabriel Sánchez-Mairata, J. M. Valencia, A. Box, S. Pinya, S. Tejada, Antoni Sureda
Global change produces substantial modification to the distribution and rhythm of infection of diseases in fish, favouring the introduction of new pathogens. Recently, the presence of black spot disease, associated with a digenean fluke of the genus Scaphanocephalus, has been observed in specimens of Xyrichthys novacula on the island of Ibiza (Balearic Islands). The aim of the present study was to evaluate the antioxidant and immune response in both the skin mucus and spleen of X. novacula depending on the degree of infection by Scaphanocephalus sp. The specimens were captured in a control area, without the presence of the parasite, and in an affected area, classifying the fish as low infection (1–15 spots) and high infection (>15 spots). As the degree of infection increased, a decrease in the body condition index was observed. The activity of the antioxidant enzymes in the mucus—catalase, superoxide dismutase and glutathione peroxidase—increased progressively with the degree of infection. This activation of antioxidant defences was not enough to prevent an increase in malondialdehyde levels, an indicator of oxidative damage, in the group with the highest infection. Similarly, an increase in immunological parameters—lysozyme, alkaline phosphatase, myeloperoxidase and immunoglobulins—was observed in mucus as infection increased. Regarding the spleen, only an increase in lysozyme activity and alkaline phosphatase in fish with a greater severity of infection was observed. In conclusion, as the severity of Scaphanocephalus sp. infection increased, it induced an immune and oxidative stress response in skin mucus, leading to a decrease in overall body condition. The potential health effects that the ectoparasite may have on X. novacula populations will require follow-up studies.
{"title":"Immune and Oxidative Stress Response of the Fish Xyrichthys novacula Infected with the Trematode Ectoparasite Scaphanocephalus sp. in the Balearic Islands","authors":"Amanda Cohen-Sánchez, Antoni Gabriel Sánchez-Mairata, J. M. Valencia, A. Box, S. Pinya, S. Tejada, Antoni Sureda","doi":"10.3390/fishes8120600","DOIUrl":"https://doi.org/10.3390/fishes8120600","url":null,"abstract":"Global change produces substantial modification to the distribution and rhythm of infection of diseases in fish, favouring the introduction of new pathogens. Recently, the presence of black spot disease, associated with a digenean fluke of the genus Scaphanocephalus, has been observed in specimens of Xyrichthys novacula on the island of Ibiza (Balearic Islands). The aim of the present study was to evaluate the antioxidant and immune response in both the skin mucus and spleen of X. novacula depending on the degree of infection by Scaphanocephalus sp. The specimens were captured in a control area, without the presence of the parasite, and in an affected area, classifying the fish as low infection (1–15 spots) and high infection (>15 spots). As the degree of infection increased, a decrease in the body condition index was observed. The activity of the antioxidant enzymes in the mucus—catalase, superoxide dismutase and glutathione peroxidase—increased progressively with the degree of infection. This activation of antioxidant defences was not enough to prevent an increase in malondialdehyde levels, an indicator of oxidative damage, in the group with the highest infection. Similarly, an increase in immunological parameters—lysozyme, alkaline phosphatase, myeloperoxidase and immunoglobulins—was observed in mucus as infection increased. Regarding the spleen, only an increase in lysozyme activity and alkaline phosphatase in fish with a greater severity of infection was observed. In conclusion, as the severity of Scaphanocephalus sp. infection increased, it induced an immune and oxidative stress response in skin mucus, leading to a decrease in overall body condition. The potential health effects that the ectoparasite may have on X. novacula populations will require follow-up studies.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138596555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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