Freshwater turtles are among the least studied faunas in the Andaman and Nicobar Islands, India. Here, we report the presence of freshwater turtles (Cuora amboinensis) from Car Nicobar, a small remote island in the Nicobar archipelago comprising the Andaman and Nicobar Islands. Semi-structured interviews were conducted with the people belonging to Nicobarese tribes (n = 233) to gather their local ecological knowledge as supportive information to obtain a better understanding of the status of turtles in Car Nicobar. Most interviewees (90%) opined that freshwater turtles are found to be rare or very rare on the Island. All the respondents (100%) expressed willingness to contribute to future conservation projects. Community-level awareness emerged as a prominent issue for future conservation using the Garrett ranking method. A stream network map was prepared using the digital elevation model to visualize streams and potential habitats of turtles. This report on the freshwater turtles is essential from an ecological perspective since information is scarce on the freshwater turtles in Car Nicobar. This study emphasizes the importance of the engagement of stakeholders in conservation projects and recommends providing adequate attention to the conservation and protection of freshwater turtle diversity in Car Nicobar.
{"title":"Aboriginal Tribe’s Knowledge of the Endangered Freshwater Turtle Cuora amboinensis in Car Nicobar, a Remote Oceanic Island in the Bay of Bengal","authors":"Rajendran Kiruba-Sankar, Sirisha Adamala, Jessica Barman, Kandasamy Saravanan, Jayasimhan Praveenraj, Eswaran Yuvaraj, Gokhlesh Kumar, Sheikh Zamir Ahmed","doi":"10.3390/fishes8100517","DOIUrl":"https://doi.org/10.3390/fishes8100517","url":null,"abstract":"Freshwater turtles are among the least studied faunas in the Andaman and Nicobar Islands, India. Here, we report the presence of freshwater turtles (Cuora amboinensis) from Car Nicobar, a small remote island in the Nicobar archipelago comprising the Andaman and Nicobar Islands. Semi-structured interviews were conducted with the people belonging to Nicobarese tribes (n = 233) to gather their local ecological knowledge as supportive information to obtain a better understanding of the status of turtles in Car Nicobar. Most interviewees (90%) opined that freshwater turtles are found to be rare or very rare on the Island. All the respondents (100%) expressed willingness to contribute to future conservation projects. Community-level awareness emerged as a prominent issue for future conservation using the Garrett ranking method. A stream network map was prepared using the digital elevation model to visualize streams and potential habitats of turtles. This report on the freshwater turtles is essential from an ecological perspective since information is scarce on the freshwater turtles in Car Nicobar. This study emphasizes the importance of the engagement of stakeholders in conservation projects and recommends providing adequate attention to the conservation and protection of freshwater turtle diversity in Car Nicobar.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135889014","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}
Monitoring and understanding the behavior of fishing vessels are important in facilitating effective management, preventing illegal fishing, informing fishing grounds and evaluating effects of harvests on fishery resources. In recent decades, a large quantity of real-time data of fishing vessels have become available with the development of vessel-tracking systems, making it possible to study the behavior of fishing vessels in high spatial and temporal resolutions. To effectively and efficiently deal with the large amount of data, algorithms from artificial intelligence (AI) are increasingly applied in the study of fishing vessel behavior. In this paper, we first introduce the various data sources for studying fishing vessel behavior and compare their pros and cons. Secondly, we review the AI methods that have been used to monitor and extract the behavior of fishing vessels from big data. Then, studies on the physical, ecological and social mechanisms affecting the behavior of fishing vessels were synthesized. Lastly, we review the applications of fishing vessel behavior in fishery science and management.
{"title":"Application of Artificial Intelligence in the Study of Fishing Vessel Behavior","authors":"Xin Cheng, Fan Zhang, Xinjun Chen, Jintao Wang","doi":"10.3390/fishes8100516","DOIUrl":"https://doi.org/10.3390/fishes8100516","url":null,"abstract":"Monitoring and understanding the behavior of fishing vessels are important in facilitating effective management, preventing illegal fishing, informing fishing grounds and evaluating effects of harvests on fishery resources. In recent decades, a large quantity of real-time data of fishing vessels have become available with the development of vessel-tracking systems, making it possible to study the behavior of fishing vessels in high spatial and temporal resolutions. To effectively and efficiently deal with the large amount of data, algorithms from artificial intelligence (AI) are increasingly applied in the study of fishing vessel behavior. In this paper, we first introduce the various data sources for studying fishing vessel behavior and compare their pros and cons. Secondly, we review the AI methods that have been used to monitor and extract the behavior of fishing vessels from big data. Then, studies on the physical, ecological and social mechanisms affecting the behavior of fishing vessels were synthesized. Lastly, we review the applications of fishing vessel behavior in fishery science and management.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135888448","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}
The ability to differentiate between various fish species plays an essential role in aquaculture. It helps to protect their populations and monitor their health situations and their nutrient systems. However, old machine learning methods are unable to detect objects in images with complex backgrounds and especially in low-light conditions. This paper aims to improve the performance of a YOLO v5 model for fish recognition and classification. In the context of transfer learning, our improved model FishDETECT uses the pre-trained FishMask model. Then it is tested in various complex scenes. The experimental results show that FishDETECT is more effective than a simple YOLO v5 model. Using the evaluation metrics Precision, Recall, and mAP50, our new model achieved accuracy rates of 0.962, 0.978, and 0.995, respectively.
{"title":"An Improved Deep Learning Model for Underwater Species Recognition in Aquaculture","authors":"Mahdi Hamzaoui, Mohamed Ould-Elhassen Aoueileyine, Lamia Romdhani, Ridha Bouallegue","doi":"10.3390/fishes8100514","DOIUrl":"https://doi.org/10.3390/fishes8100514","url":null,"abstract":"The ability to differentiate between various fish species plays an essential role in aquaculture. It helps to protect their populations and monitor their health situations and their nutrient systems. However, old machine learning methods are unable to detect objects in images with complex backgrounds and especially in low-light conditions. This paper aims to improve the performance of a YOLO v5 model for fish recognition and classification. In the context of transfer learning, our improved model FishDETECT uses the pre-trained FishMask model. Then it is tested in various complex scenes. The experimental results show that FishDETECT is more effective than a simple YOLO v5 model. Using the evaluation metrics Precision, Recall, and mAP50, our new model achieved accuracy rates of 0.962, 0.978, and 0.995, respectively.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136114695","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}
Maheshkumar Prakash Patil, Jong-Oh Kim, Seung Hyun Yoo, Yong Bae Seo, Yu-Jin Lee, Jin-Koo Kim, Shin-Ichi Kitamura, Gun-Do Kim
Alcichthys elongatus is the only species in the genus, and this work is the first to provide a comprehensive mitogenome analysis of this species. The A. elongatus mitogenome was 16,712 bp long, with biased A + T content (52.33%), and featured thirteen protein-coding genes (PCGs), twenty-two tRNAs, two rRNAs, and the control region (D-loop). The H strand encoded twenty-eight genes (twelve PCGs, fourteen tRNA, and two rRNA) and the control region, whereas the L strand encoded the remaining nine genes (ND6 and eight tRNA). Except for COXI, which started with GTG, all PCG sequences started with ATG and ended with TAA (ND4L, ND5, COXI, ATP8) or TAG (ND1, ND6) termination codons, with some (ND2, ND3, ND4, COXII, COXIII, ATP6, Cytb) having an incomplete termination codon. Except for tRNA-serine-1 (trnS), the majority of the tRNAs exhibited characteristic cloverleaf secondary structures. Based on 13 PCGs, phylogenetic analysis placed A. elongatus in the same clade as Icelus spatula. This genomic data will be useful for species identification, phylogenetic analysis, and population genetics.
{"title":"Complete Mitogenome and Phylogenetic Analysis of a Marine Ray-Finned Fish, Alcichthys elongatus (Perciformes: Cottidae)","authors":"Maheshkumar Prakash Patil, Jong-Oh Kim, Seung Hyun Yoo, Yong Bae Seo, Yu-Jin Lee, Jin-Koo Kim, Shin-Ichi Kitamura, Gun-Do Kim","doi":"10.3390/fishes8100513","DOIUrl":"https://doi.org/10.3390/fishes8100513","url":null,"abstract":"Alcichthys elongatus is the only species in the genus, and this work is the first to provide a comprehensive mitogenome analysis of this species. The A. elongatus mitogenome was 16,712 bp long, with biased A + T content (52.33%), and featured thirteen protein-coding genes (PCGs), twenty-two tRNAs, two rRNAs, and the control region (D-loop). The H strand encoded twenty-eight genes (twelve PCGs, fourteen tRNA, and two rRNA) and the control region, whereas the L strand encoded the remaining nine genes (ND6 and eight tRNA). Except for COXI, which started with GTG, all PCG sequences started with ATG and ended with TAA (ND4L, ND5, COXI, ATP8) or TAG (ND1, ND6) termination codons, with some (ND2, ND3, ND4, COXII, COXIII, ATP6, Cytb) having an incomplete termination codon. Except for tRNA-serine-1 (trnS), the majority of the tRNAs exhibited characteristic cloverleaf secondary structures. Based on 13 PCGs, phylogenetic analysis placed A. elongatus in the same clade as Icelus spatula. This genomic data will be useful for species identification, phylogenetic analysis, and population genetics.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136115579","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}
The biofloc technology system (BFT) is considered to be one of the sustainable aquaculture systems, which is based on the principle of nutrient recycling with the addition of a carbon source to give dominance to heterotrophic microorganisms. The objective of this study was to evaluate the effect of sugar cane molasses and tapioca flour as carbon sources on the water quality, growth, hematology, immune status, and non-specific antioxidant status of Oreochromis juveniles. Methodologically, the experiment was carried out for 10 weeks on 225 juvenile Nile tilapia with initial body weights of 47.0 ± 1.3 g that were randomly distributed in 09 tanks (1000 L) with a stocking density of 25 tilapias per tank; the treatments were: BFT + SM (S molasses), BFT + TF tapioca flour (TF), and a control with no carbon source added. The control group was fed 100% feed, while the BFT experimental groups were fed microbial flocs along with 75% feed. The results revealed that the water quality parameters were affected by the carbon sources, but were adequate for normal fish welfare, and the biofloc volume was higher (28.94) with the TF carbon source. The growth performance, such as weight gain (98.61), survival (99.01), and improved feed conversion ratio (FCR) (1.69), was recorded in BFT + TF. Significant improvements in WBCs, HCT, HB, lymphocytes, plasma proteins, albumin, and non-specific immune factors (lysozyme activity, immunoglobulins levels, and ACH50) were observed in biofloc-reared fish with tapioca flour as the carbon source compared to the control and sugarcane molasses groups. Moreover, significant increases in catalase (CAT) and superoxide dismutase (SOD) were found in the biofloc-reared fish with different carbon sources. In conclusion, the use of BFT + TF was found to affect improving the water quality, growth, hematology, immunity, and antioxidant status of juvenile Tilapia.
{"title":"The Effects of Different Carbon Sources on Water Quality, Growth Performance, Hematology, Immune, and Antioxidant Status in Cultured Nile Tilapia with Biofloc Technology","authors":"Khalid Hussain Rind, Syed Sikandar Habib, Javed Ahmed Ujan, Francesco Fazio, Saira Naz, Aima Iram Batool, Mujeeb Ullah, Sobia Attaullah, Khayyam Khayyam, Khalid Khan","doi":"10.3390/fishes8100512","DOIUrl":"https://doi.org/10.3390/fishes8100512","url":null,"abstract":"The biofloc technology system (BFT) is considered to be one of the sustainable aquaculture systems, which is based on the principle of nutrient recycling with the addition of a carbon source to give dominance to heterotrophic microorganisms. The objective of this study was to evaluate the effect of sugar cane molasses and tapioca flour as carbon sources on the water quality, growth, hematology, immune status, and non-specific antioxidant status of Oreochromis juveniles. Methodologically, the experiment was carried out for 10 weeks on 225 juvenile Nile tilapia with initial body weights of 47.0 ± 1.3 g that were randomly distributed in 09 tanks (1000 L) with a stocking density of 25 tilapias per tank; the treatments were: BFT + SM (S molasses), BFT + TF tapioca flour (TF), and a control with no carbon source added. The control group was fed 100% feed, while the BFT experimental groups were fed microbial flocs along with 75% feed. The results revealed that the water quality parameters were affected by the carbon sources, but were adequate for normal fish welfare, and the biofloc volume was higher (28.94) with the TF carbon source. The growth performance, such as weight gain (98.61), survival (99.01), and improved feed conversion ratio (FCR) (1.69), was recorded in BFT + TF. Significant improvements in WBCs, HCT, HB, lymphocytes, plasma proteins, albumin, and non-specific immune factors (lysozyme activity, immunoglobulins levels, and ACH50) were observed in biofloc-reared fish with tapioca flour as the carbon source compared to the control and sugarcane molasses groups. Moreover, significant increases in catalase (CAT) and superoxide dismutase (SOD) were found in the biofloc-reared fish with different carbon sources. In conclusion, the use of BFT + TF was found to affect improving the water quality, growth, hematology, immunity, and antioxidant status of juvenile Tilapia.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135765995","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}
Daniel E. Sadler, Phillip C. Watts, Silva Uusi-Heikkilä
Overfishing drives population decline, which in turn drives loss of genetic diversity. Many studies provide evidence of declines in genetic diversity; however, controversy exists within the literature, as some studies show evidence of no change in genetic diversity despite decades of overharvesting. The apparent discrepancy in the literature should therefore be examined to understand what biological and ecological processes are driving the differences in results. Here, we assess how different factors contribute to fisheries-induced susceptibility to declines in genetic diversity by first focusing on the different roles of genetic markers. Second, we assess how habitat type and conditions contribute to loss of genetic diversity. Third, we assess how life history and physiology affects catchability and loss of genetic diversity. Finally, we discuss how coinciding abiotic and biotic factors influence the intensity of genetic loss. We find a multitude of these factors could be interacting to influence how results are perceived and how intense the loss of genetic diversity can be. Future studies should carefully consider the methodology of genetic analysis used, as well as considerations of life history and ecology of the target species.
{"title":"The Riddle of How Fisheries Influence Genetic Diversity","authors":"Daniel E. Sadler, Phillip C. Watts, Silva Uusi-Heikkilä","doi":"10.3390/fishes8100510","DOIUrl":"https://doi.org/10.3390/fishes8100510","url":null,"abstract":"Overfishing drives population decline, which in turn drives loss of genetic diversity. Many studies provide evidence of declines in genetic diversity; however, controversy exists within the literature, as some studies show evidence of no change in genetic diversity despite decades of overharvesting. The apparent discrepancy in the literature should therefore be examined to understand what biological and ecological processes are driving the differences in results. Here, we assess how different factors contribute to fisheries-induced susceptibility to declines in genetic diversity by first focusing on the different roles of genetic markers. Second, we assess how habitat type and conditions contribute to loss of genetic diversity. Third, we assess how life history and physiology affects catchability and loss of genetic diversity. Finally, we discuss how coinciding abiotic and biotic factors influence the intensity of genetic loss. We find a multitude of these factors could be interacting to influence how results are perceived and how intense the loss of genetic diversity can be. Future studies should carefully consider the methodology of genetic analysis used, as well as considerations of life history and ecology of the target species.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135857077","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}
Zhengli Luo, Yanbo Zhou, Ning Liu, Liangming Wang, Yan Liu, Binbin Shan, Manting Liu, Cheng Chen, Changping Yang, Dianrong Sun
This study explored the ecological niche and interspecific relationships among the main fish species in the coastal waters of Hainan Island based on data from fishery stock surveys conducted in the spring and autumn of 2022. The methods of chi-square test, percentage of co-occurrence (PC), association coefficient (AC), cluster analysis, and redundancy analysis were used to analyze the interspecific associations and influence of environmental factors on the ecological niches of fish communities. According to the cluster analysis of niche breadth, 20 main fishes could be divided into broad, medium, and narrow niche species. There were four and eight broad niche species in spring and autumn, respectively. The ranges of niche overlap values were 0.001–0.91 in spring and 0–0.87 in autumn, indicating that the species differed and were similar in their ability to utilize resources, survive in habitats, and prey. According to the variance ratio and statistic value W, the main fishes in spring showed a significant positive association, whereas those in autumn showed a positive association, but not at a significant level, indicating that the main fishes in spring were more closely associated with each other. There were 56 species pairs in the 2 seasons that were significantly associated (χ2 ≥ 3.841). AC and PC tests revealed that the interspecific association was strong and tended to be positive. According to the redundancy analysis, environmental factors such as surface temperature, water depth, and pH significantly affected the main fishes in spring, while environmental factors such as dissolved oxygen, bottom temperature, surface salinity, and pH significantly affected those in autumn.
{"title":"Ecological Niche and Interspecific Association of the Main Fishes in the Coastal Waters of Hainan Island, China","authors":"Zhengli Luo, Yanbo Zhou, Ning Liu, Liangming Wang, Yan Liu, Binbin Shan, Manting Liu, Cheng Chen, Changping Yang, Dianrong Sun","doi":"10.3390/fishes8100511","DOIUrl":"https://doi.org/10.3390/fishes8100511","url":null,"abstract":"This study explored the ecological niche and interspecific relationships among the main fish species in the coastal waters of Hainan Island based on data from fishery stock surveys conducted in the spring and autumn of 2022. The methods of chi-square test, percentage of co-occurrence (PC), association coefficient (AC), cluster analysis, and redundancy analysis were used to analyze the interspecific associations and influence of environmental factors on the ecological niches of fish communities. According to the cluster analysis of niche breadth, 20 main fishes could be divided into broad, medium, and narrow niche species. There were four and eight broad niche species in spring and autumn, respectively. The ranges of niche overlap values were 0.001–0.91 in spring and 0–0.87 in autumn, indicating that the species differed and were similar in their ability to utilize resources, survive in habitats, and prey. According to the variance ratio and statistic value W, the main fishes in spring showed a significant positive association, whereas those in autumn showed a positive association, but not at a significant level, indicating that the main fishes in spring were more closely associated with each other. There were 56 species pairs in the 2 seasons that were significantly associated (χ2 ≥ 3.841). AC and PC tests revealed that the interspecific association was strong and tended to be positive. According to the redundancy analysis, environmental factors such as surface temperature, water depth, and pH significantly affected the main fishes in spring, while environmental factors such as dissolved oxygen, bottom temperature, surface salinity, and pH significantly affected those in autumn.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135918116","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}
Jiyuan Li, Yanfeng Wang, Teng Guo, Shihong Xu, Guang Gao, Feng Liu, Xiaoyang Guo, Yanduo Wu, Haixia Zhao, Jun Li
Pheromones play a vital role in regulating fish behavior, including reproduction, aggregation, hazard recognition and food location. To gain a better understanding of chemical communication in fish produced by density changes, this study analyzed the metabolites released by turbot (Scophthalmus maximus) under different stocking densities. The experiment was conducted at low (LD: 3.01 kg/m2), medium (MD: 6.62 kg/m2) and high (HD: 10.84 kg/m2) densities for 15 days. High-throughput non-targeted metabolomics (LC-MS/MS) was used to identify variations in metabolites released into the aquatic environment by turbot at different densities. Results showed that 29 and 47 metabolites were significantly upregulated in the MD and HD groups, respectively, compared with the LD group. Among them, hexadecanedioic acid, xanthine, phenethylamine, proline and styrene were significantly upregulated in the MD vs. LD, HD vs. MD and HD vs. LD. The VIP diagram of OPLS-DA alignment showed that phenethylamine was the most important metabolite shared by MD vs. LD, HD vs. MD and HD vs. LD. Key gene changes in the GH/IGF-1 signaling pathway, HPI axis of turbot were studied using qRT-PCR for density treatment. The results demonstrated that the expression of GH, GHR and IGF-1 was significantly lower, while the expression of CRH and ACTH was higher in the HD group. Additionally, plasma levels of cortisol, glucose, triglycerides and T3 were also highest in the HD group compared with the LD and MD groups. Phenylethylamine concentration was positively correlated with the HPI axis and negatively correlated with the GH/IGF-1 signaling pathway. To investigate the impact of phenethylamine accumulation on turbot, an acute treatment experiment with phenethylamine was set up. Its concentration in the aquatic environment was set at 0 (CON), 10−7 (LP) and 10−5 (HP) mol/L via exogenous addition, and turbot were exposed to these environments for 2 days. There was a high degree of concordance between the GH/IGF-1 signaling pathway (GH, GHR, IGF-1), HPI axis (CRH, ACTH) and plasma physiological changes (cortisol, glucose, triglycerides, T3) in the phenethylamine-treated group and the density-treated group. Therefore, accumulation of phenethylamine with increasing stocking density may be a potential cause of density stress. Phenylethylamine has a dose-dependent and trace effect as a pheromone.
信息素在调节鱼类的繁殖、聚集、危险识别和食物定位等行为中起着至关重要的作用。为了更好地了解密度变化对鱼类体内化学通讯的影响，本研究分析了不同放养密度下大菱鲆(Scophthalmus maximus)释放的代谢物。试验在低密度(LD: 3.01 kg/m2)、中密度(MD: 6.62 kg/m2)和高密度(HD: 10.84 kg/m2)下进行，为期15 d。采用高通量非靶向代谢组学(LC-MS/MS)技术鉴定不同密度大比目鱼释放到水生环境中的代谢物的变化。结果显示，与LD组相比，MD组和HD组分别有29和47种代谢物显著上调。其中，十六烯二酸、黄嘌呤、苯乙胺、脯氨酸和苯乙烯在MD vs LD、HD vs MD和HD vs LD中显著上调。OPLS-DA比对VIP图显示，苯乙胺是MD vs LD、HD vs MD和HD vs LD中最重要的共同代谢物。结果显示，HD组GH、GHR、IGF-1的表达明显降低，CRH、ACTH的表达明显升高。此外，与LD和MD组相比，HD组的血浆皮质醇、葡萄糖、甘油三酯和T3水平也最高。苯乙胺浓度与HPI轴呈正相关，与GH/IGF-1信号通路负相关。为了研究苯乙胺积累对大菱鲆的影响，建立了苯乙胺急性治疗实验。通过外源添加将其在水生环境中的浓度设定为0 (CON)、10−7 (LP)和10−5 (HP) mol/L，并在这些环境中暴露2天。苯乙胺处理组与密度处理组GH/IGF-1信号通路(GH、GHR、IGF-1)、HPI轴(CRH、ACTH)与血浆生理变化(皮质醇、葡萄糖、甘油三酯、T3)高度一致。因此，随着放养密度的增加，苯乙胺的积累可能是密度胁迫的潜在原因。苯乙胺作为一种信息素具有剂量依赖性和痕量效应。
{"title":"Phenethylamine Is a Potential Density Stress Pheromone in Turbot (Scophthalmus maximus)","authors":"Jiyuan Li, Yanfeng Wang, Teng Guo, Shihong Xu, Guang Gao, Feng Liu, Xiaoyang Guo, Yanduo Wu, Haixia Zhao, Jun Li","doi":"10.3390/fishes8100506","DOIUrl":"https://doi.org/10.3390/fishes8100506","url":null,"abstract":"Pheromones play a vital role in regulating fish behavior, including reproduction, aggregation, hazard recognition and food location. To gain a better understanding of chemical communication in fish produced by density changes, this study analyzed the metabolites released by turbot (Scophthalmus maximus) under different stocking densities. The experiment was conducted at low (LD: 3.01 kg/m2), medium (MD: 6.62 kg/m2) and high (HD: 10.84 kg/m2) densities for 15 days. High-throughput non-targeted metabolomics (LC-MS/MS) was used to identify variations in metabolites released into the aquatic environment by turbot at different densities. Results showed that 29 and 47 metabolites were significantly upregulated in the MD and HD groups, respectively, compared with the LD group. Among them, hexadecanedioic acid, xanthine, phenethylamine, proline and styrene were significantly upregulated in the MD vs. LD, HD vs. MD and HD vs. LD. The VIP diagram of OPLS-DA alignment showed that phenethylamine was the most important metabolite shared by MD vs. LD, HD vs. MD and HD vs. LD. Key gene changes in the GH/IGF-1 signaling pathway, HPI axis of turbot were studied using qRT-PCR for density treatment. The results demonstrated that the expression of GH, GHR and IGF-1 was significantly lower, while the expression of CRH and ACTH was higher in the HD group. Additionally, plasma levels of cortisol, glucose, triglycerides and T3 were also highest in the HD group compared with the LD and MD groups. Phenylethylamine concentration was positively correlated with the HPI axis and negatively correlated with the GH/IGF-1 signaling pathway. To investigate the impact of phenethylamine accumulation on turbot, an acute treatment experiment with phenethylamine was set up. Its concentration in the aquatic environment was set at 0 (CON), 10−7 (LP) and 10−5 (HP) mol/L via exogenous addition, and turbot were exposed to these environments for 2 days. There was a high degree of concordance between the GH/IGF-1 signaling pathway (GH, GHR, IGF-1), HPI axis (CRH, ACTH) and plasma physiological changes (cortisol, glucose, triglycerides, T3) in the phenethylamine-treated group and the density-treated group. Therefore, accumulation of phenethylamine with increasing stocking density may be a potential cause of density stress. Phenylethylamine has a dose-dependent and trace effect as a pheromone.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136062670","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}
Fabio A. C. Santos, Felipe S. Batista, André S. Souza, Gustavo S. C. Julio, Gisele C. Favero, José F. V. Junior, Sílvio T. Costa, Carla C. Zeppenfeld, Nadia H. Bianchini, Berta M. Heinzmann, Bernardo Baldisserotto, Ronald K. Luz
The present study evaluated different levels of the essential oil of Nectandra grandiflora (EONG) in the diet of juvenile Colossoma macropomum. The juveniles (0.75 ± 0.05 g) were fed four experimental diets with differing levels of EONG (0, 0.5, 0.75, and 1.50 mL/kg). After 20 days, the weight, daily weight gain, specific growth rate, and daily feed consumption per fish were highest for the fish fed 0.5 mL EONG/kg, while after 30 days, only the weight and daily feed consumption per fish for that diet remained highest. The viscerosomatic index was highest for the fish fed 0.5 mL EONG/kg while the hepatosomatic index was higher for the groups that received dietary EONG for 30 days. The juveniles fed 1.5 mL EONG/kg showed a proliferative response of the mucous cells in the gills, but the proliferation of these lysozyme- and immunoglobulin-secreting mucosal cells was higher for the skin of the fish of all EONG levels, compared to that of the control fish. The fish fed 0.5 mL EONG/kg had the greatest height and width of intestinal villi. The two highest levels of dietary EONG supplementation (0.75 and 1.50 mL/kg) reduced the hepatocyte dimensions but did not modify the centrolobular vein area. Dietary supplementation with 0.5 mL EONG/kg improved the growth, gut health, and immune response of juvenile C. macropomum.
本研究评价了大巨像幼鱼饲料中不同含量的桔黄精油(EONG)。分别饲喂4种不同EONG水平(0、0.5、0.75和1.50 mL/kg)的试验饲料(0.75±0.05 g)。饲喂0.5 mL EONG/kg的饲料20 d后，鱼的体重、日增重、特定生长率和日饲料消耗量最高，30 d后，只有该饲料的鱼的体重和日饲料消耗量最高。饲喂0.5 mL EONG/kg组内脏体指数最高，饲喂30 d EONG组肝体指数最高。饲喂1.5 mL /kg EONG的幼鱼鳃粘膜细胞均表现出增殖反应，但与对照鱼相比，所有EONG水平的幼鱼皮肤中溶菌酶和免疫球蛋白分泌粘膜细胞的增殖均较高。饲喂0.5 mL EONG/kg的鱼肠绒毛高度和宽度最大。饲粮中添加两种最高水平的EONG(0.75和1.50 mL/kg)降低了肝细胞的尺寸，但没有改变小叶中心静脉面积。饲粮中添加0.5 mL EONG/kg可改善大鲤幼鱼的生长、肠道健康和免疫反应。
{"title":"Growth Performance and Histomorphology of Intestine, Skin, Gills and Liver of Juvenile Colossoma macropomum Fed Diets Containing Different Levels of the Essential Oil of Nectandra grandiflora","authors":"Fabio A. C. Santos, Felipe S. Batista, André S. Souza, Gustavo S. C. Julio, Gisele C. Favero, José F. V. Junior, Sílvio T. Costa, Carla C. Zeppenfeld, Nadia H. Bianchini, Berta M. Heinzmann, Bernardo Baldisserotto, Ronald K. Luz","doi":"10.3390/fishes8100509","DOIUrl":"https://doi.org/10.3390/fishes8100509","url":null,"abstract":"The present study evaluated different levels of the essential oil of Nectandra grandiflora (EONG) in the diet of juvenile Colossoma macropomum. The juveniles (0.75 ± 0.05 g) were fed four experimental diets with differing levels of EONG (0, 0.5, 0.75, and 1.50 mL/kg). After 20 days, the weight, daily weight gain, specific growth rate, and daily feed consumption per fish were highest for the fish fed 0.5 mL EONG/kg, while after 30 days, only the weight and daily feed consumption per fish for that diet remained highest. The viscerosomatic index was highest for the fish fed 0.5 mL EONG/kg while the hepatosomatic index was higher for the groups that received dietary EONG for 30 days. The juveniles fed 1.5 mL EONG/kg showed a proliferative response of the mucous cells in the gills, but the proliferation of these lysozyme- and immunoglobulin-secreting mucosal cells was higher for the skin of the fish of all EONG levels, compared to that of the control fish. The fish fed 0.5 mL EONG/kg had the greatest height and width of intestinal villi. The two highest levels of dietary EONG supplementation (0.75 and 1.50 mL/kg) reduced the hepatocyte dimensions but did not modify the centrolobular vein area. Dietary supplementation with 0.5 mL EONG/kg improved the growth, gut health, and immune response of juvenile C. macropomum.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136210276","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}
This study aimed to investigate the effect of reduced expression of the luxR gene on the virulence of Pseudomonas plecoglossicida and the immune response of Epinephelus coioides. To achieve this, RNA interference (RNAi) was used to silence the luxR gene, and the pathogenicity of wild-type and luxR-RNAi strains of P. plecoglossicida, as well as the immune response of Epinephelus coioides to the infection of these two strains, were compared. The mutant strain with the highest silencing efficiency of 70.1% was selected for subsequent analysis. Silencing the luxR gene in the mutant strain resulted in a significant 30% reduction in mortality rates in artificially infected Epinephelus coioides compared to the wild-type strain. Transcriptome analysis revealed that the host transcriptome, particularly in the spleens of infected Epinephelus coioides, was markedly altered by the silencing of the luxR gene in the mutant strain. Tilapia infected with the luxR-RNAi strain exhibited altered immune defenses, with changes in gene expression primarily in the NOD-like receptor (NLR) signaling pathway. These results suggest that the luxR gene plays a crucial role in the host’s resistance to pathogen invasion, and reducing its expression could decrease quorum sensing (QS) signals while increasing the expression of the IL-1β gene in the host’s NLR pathway. This effect may lead to a pro-inflammatory response that enhances the immune response to infection. Further investigation of these mechanisms may lead to innovative approaches to treating bacterial infections.
{"title":"How the luxR Gene Affects the Pathogenicity of Pseudomonas plecoglossicida and the Immune Response of Epinephelus coioides","authors":"Lingmin Zhao, Lixing Huang, Yingxue Qin, Dou Yang, Jiaonan Zhang, Jiaolin Zhang, Qingpi Yan","doi":"10.3390/fishes8100507","DOIUrl":"https://doi.org/10.3390/fishes8100507","url":null,"abstract":"This study aimed to investigate the effect of reduced expression of the luxR gene on the virulence of Pseudomonas plecoglossicida and the immune response of Epinephelus coioides. To achieve this, RNA interference (RNAi) was used to silence the luxR gene, and the pathogenicity of wild-type and luxR-RNAi strains of P. plecoglossicida, as well as the immune response of Epinephelus coioides to the infection of these two strains, were compared. The mutant strain with the highest silencing efficiency of 70.1% was selected for subsequent analysis. Silencing the luxR gene in the mutant strain resulted in a significant 30% reduction in mortality rates in artificially infected Epinephelus coioides compared to the wild-type strain. Transcriptome analysis revealed that the host transcriptome, particularly in the spleens of infected Epinephelus coioides, was markedly altered by the silencing of the luxR gene in the mutant strain. Tilapia infected with the luxR-RNAi strain exhibited altered immune defenses, with changes in gene expression primarily in the NOD-like receptor (NLR) signaling pathway. These results suggest that the luxR gene plays a crucial role in the host’s resistance to pathogen invasion, and reducing its expression could decrease quorum sensing (QS) signals while increasing the expression of the IL-1β gene in the host’s NLR pathway. This effect may lead to a pro-inflammatory response that enhances the immune response to infection. Further investigation of these mechanisms may lead to innovative approaches to treating bacterial infections.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136211000","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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