The aim of this study was to investigate the effects of imbalanced dietary BCAAs, especially Leu, on the growth and BCAA metabolism in turbot. A control diet was formulated by keeping optimum levels of Leu, Ile and Val. Four experimental diets were prepared by removing supplemental crystalline Leu (deficiency) or supplementing double the amount of Leu, Ile or Val (excess) in the control diet. The growth was not significantly decreased by an excess of Leu, Ile or Val. Fish fed an excess of any particular BCAA significantly increased its postprandial (2 and 6 h) concentration in the plasma, muscles, and liver, but did not decrease the other two BCAA concentrations. The expression of intestinal b0at1 was down-regulated by excessive dietary Leu, Ile or Val. For BCAA catabolism, the mRNA levels of bcat2 in the muscles as well as bckdha and bckdha in the livers of the Leu-deficient group were the lowest among all the groups, but were up-regulated by excess dietary Leu, Ile or Val. In conclusion, in terms of growth, turbot had high plasticity to an excess of any particular BCAA. Meanwhile, the antagonistic effect caused by an excess of one BCAA were reflected in intestinal amino acid absorption and BCAA catabolism.
{"title":"Response of Turbot Scophthalmus maximus (Linnaeus, 1758) to Imbalanced Branched-Chain Amino Acids in Diets","authors":"Lu Wang, Jinshi Liu, Yanlu Li, Qiang Ma, Houguo Xu, Mengqing Liang, Yuliang Wei","doi":"10.3390/fishes8110534","DOIUrl":"https://doi.org/10.3390/fishes8110534","url":null,"abstract":"The aim of this study was to investigate the effects of imbalanced dietary BCAAs, especially Leu, on the growth and BCAA metabolism in turbot. A control diet was formulated by keeping optimum levels of Leu, Ile and Val. Four experimental diets were prepared by removing supplemental crystalline Leu (deficiency) or supplementing double the amount of Leu, Ile or Val (excess) in the control diet. The growth was not significantly decreased by an excess of Leu, Ile or Val. Fish fed an excess of any particular BCAA significantly increased its postprandial (2 and 6 h) concentration in the plasma, muscles, and liver, but did not decrease the other two BCAA concentrations. The expression of intestinal b0at1 was down-regulated by excessive dietary Leu, Ile or Val. For BCAA catabolism, the mRNA levels of bcat2 in the muscles as well as bckdha and bckdha in the livers of the Leu-deficient group were the lowest among all the groups, but were up-regulated by excess dietary Leu, Ile or Val. In conclusion, in terms of growth, turbot had high plasticity to an excess of any particular BCAA. Meanwhile, the antagonistic effect caused by an excess of one BCAA were reflected in intestinal amino acid absorption and BCAA catabolism.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"22 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134909165","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}
Annika Boussard, Stephanie Edlund, Stephanie Fong, David Wheatcroft, Niclas Kolm
Over recent decades, substantial research has focused on fish cognitive evolution to increase our understanding of the evolution of the enormous diversity of cognitive abilities that exists in fishes. One important but understudied aspect of cognitive evolution is sexual dimorphism in cognitive abilities. Sex-specific variation in brain region morphology has been proposed to be an important mechanism in this context. However, it is also common to find sex-specific variation in behavior and cognition without associated differences in brain morphology among the sexes. The telencephalon is the major cognitive center in the vertebrate brain and variation in telencephalon size has been associated with variation in cognition. Here, we utilize recently developed guppy artificial selection lines with ca. 10% differences in relative telencephalon size to investigate whether similar responses to selection of the size of this region may affect cognitive abilities differently in males and females. To that end, we compared two ecologically relevant aspects of cognition, detour learning and binary spatial discrimination. We tested the significance of the interaction between telencephalon size and sex, and we found no sex-specific effects of evolutionary increases in telencephalon size in the cognitive abilities tested. This study indicates that no clear cognitive sex-specific effects occur in response to rapid selection of telencephalon size. We suggest that future research on sexual dimorphism in cognitive abilities in fish could use various cognitive tests and examine telencephalic sub-regions to gain a more comprehensive understanding of their evolution.
{"title":"No Sex-Specific Effects of Artificial Selection for Relative Telencephalon Size during Detour Learning and Spatial Discrimination in Guppies (Poecilia reticulata)","authors":"Annika Boussard, Stephanie Edlund, Stephanie Fong, David Wheatcroft, Niclas Kolm","doi":"10.3390/fishes8110536","DOIUrl":"https://doi.org/10.3390/fishes8110536","url":null,"abstract":"Over recent decades, substantial research has focused on fish cognitive evolution to increase our understanding of the evolution of the enormous diversity of cognitive abilities that exists in fishes. One important but understudied aspect of cognitive evolution is sexual dimorphism in cognitive abilities. Sex-specific variation in brain region morphology has been proposed to be an important mechanism in this context. However, it is also common to find sex-specific variation in behavior and cognition without associated differences in brain morphology among the sexes. The telencephalon is the major cognitive center in the vertebrate brain and variation in telencephalon size has been associated with variation in cognition. Here, we utilize recently developed guppy artificial selection lines with ca. 10% differences in relative telencephalon size to investigate whether similar responses to selection of the size of this region may affect cognitive abilities differently in males and females. To that end, we compared two ecologically relevant aspects of cognition, detour learning and binary spatial discrimination. We tested the significance of the interaction between telencephalon size and sex, and we found no sex-specific effects of evolutionary increases in telencephalon size in the cognitive abilities tested. This study indicates that no clear cognitive sex-specific effects occur in response to rapid selection of telencephalon size. We suggest that future research on sexual dimorphism in cognitive abilities in fish could use various cognitive tests and examine telencephalic sub-regions to gain a more comprehensive understanding of their evolution.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135013194","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 objectives of this study were to investigate the effect of different dietary lipid levels on the serum biochemistry, antioxidant responses, initial immunity, and mTOR pathway of juvenile genetic improvement-farmed tilapia (GIFT, Oreochromis niloticus). Six groups of the juveniles (initial body weight 20.66 ± 1.33 g) in triplicate were fed for 90 days using six iso-nitrogen diets with different lipid levels (0.35%, 3.35%, 6.35%, 9.35%, 12.35%, and 15.35%). The main results were as follows: Compared with the control group (0.35%), the diets with different lipid supplementation significantly improved (p < 0.05) the contents of total protein (TP), albumin (ALB), globulin (GLB), glucose (GLU), triglyceride (TG), total cholesterol (T-CHO), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total antioxidant capacity (T-AOC), malondialdehyde (MDA), complement 3 (C3), and immunoglobulin M (IgM), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), lysozyme (LYZ), and alkaline phosphatase (ALP), the expression level of phosphatidylinositol-3-kinase (PI3K), Akt protein kinase B (Akt), and mammalian target of rapamycin (mTOR) genes in juvenile tilapia. However, diets with different lipid supplementation significantly reduced (p < 0.05) the expression level of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) genes of juvenile tilapia. In conclusion, the with different lipid supplementation could significantly affect the serum biochemistry, antioxidant responses, initial immunity, and mTOR pathway of juvenile tilapia.
{"title":"The Effect of Dietary Lipid Supplementation on the Serum Biochemistry, Antioxidant Responses, Initial Immunity, and mTOR Pathway of Juvenile Tilapia (Oreochromis niloticus)","authors":"Yongqiang Liu, Enhao Huang, Yi Xie, Liuqing Meng, Dongsheng Liu, Ziqi Zhang, Jiang Zhou, Qin Zhang, Tong Tong","doi":"10.3390/fishes8110535","DOIUrl":"https://doi.org/10.3390/fishes8110535","url":null,"abstract":"The objectives of this study were to investigate the effect of different dietary lipid levels on the serum biochemistry, antioxidant responses, initial immunity, and mTOR pathway of juvenile genetic improvement-farmed tilapia (GIFT, Oreochromis niloticus). Six groups of the juveniles (initial body weight 20.66 ± 1.33 g) in triplicate were fed for 90 days using six iso-nitrogen diets with different lipid levels (0.35%, 3.35%, 6.35%, 9.35%, 12.35%, and 15.35%). The main results were as follows: Compared with the control group (0.35%), the diets with different lipid supplementation significantly improved (p < 0.05) the contents of total protein (TP), albumin (ALB), globulin (GLB), glucose (GLU), triglyceride (TG), total cholesterol (T-CHO), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total antioxidant capacity (T-AOC), malondialdehyde (MDA), complement 3 (C3), and immunoglobulin M (IgM), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), lysozyme (LYZ), and alkaline phosphatase (ALP), the expression level of phosphatidylinositol-3-kinase (PI3K), Akt protein kinase B (Akt), and mammalian target of rapamycin (mTOR) genes in juvenile tilapia. However, diets with different lipid supplementation significantly reduced (p < 0.05) the expression level of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) genes of juvenile tilapia. In conclusion, the with different lipid supplementation could significantly affect the serum biochemistry, antioxidant responses, initial immunity, and mTOR pathway of juvenile tilapia.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136382000","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}
Dapeng Yu, Haohang Zhao, Yiming Wen, Tao Li, Hongli Xia, Zhiwen Wang, Zhen Gan, Liqun Xia, Jianlin Chen, Yishan Lu
In previous studies, natural killer lysin (NK-lysin) emerged as a crucial antimicrobial peptide (AMP) discharged by NK cells and CTLs. The sequence of NK-lysin was cloned and discovered in some fishes, but its function remains unclear. In our study, we obtained a copy of NK-lysin from the spleen of the healthy clownfish (Amphiprion ocellaris; AoNK-lysin) through cloning and proceeded to investigate its potential functions and activities. The findings showed that the AoNK-lysin gene’s open reading frame (ORF) had a length of 465 base pairs (bp) and encoded 154 amino acids (aa), which included a saposin B domain and six cysteine residues that are highly conserved, forming three intrachain disulfide bonds to carry out antimicrobial activity. The AoNK-lysin gene was widely present in different tissues, with the skin showing the highest expression, followed by the eye, intestine, and muscle. Additionally, the expression of AoNK-lysin was significantly upregulated in the immune organs (spleen, gill, intestine, and head kidney) of A. ocellaris after being challenged by Singapore group iridovirus (SGIV). Furthermore, a 399 base pair cDNA sequence that encodes the fully developed peptide of AoNK-lysin was successfully inserted into a secretion plasmid called pPIC9K. Subsequently, a significant amount of the recombinant AoNK-lysin protein was efficiently manufactured using the Pichia pastoris expression system. The antibacterial test demonstrated that the AoNK-lysin protein significantly suppressed the growth of various pathogens, particularly Streptococcus agalactiae, Streptococcus iniae, Salmonella typhi, Shigella sonnei, Pseudomonas aeruginosa, and Aeromonas caviae. The minimal inhibitory concentration (MIC) was found to be 7.81 μg/mL. Further analysis of antiviral assays showed all the viral mRNA of SGIV to be significantly reduced after AoNK-lysin protein stimuli in FHM cells. Collectively, these discoveries indicate that AoNK-lysin exhibits features of both direct pathogen-killing abilities and inhibited virus replication.
{"title":"Characterization and Functional Evaluation of NK-lysin from Clownfish (Amphiprion ocellaris)","authors":"Dapeng Yu, Haohang Zhao, Yiming Wen, Tao Li, Hongli Xia, Zhiwen Wang, Zhen Gan, Liqun Xia, Jianlin Chen, Yishan Lu","doi":"10.3390/fishes8110533","DOIUrl":"https://doi.org/10.3390/fishes8110533","url":null,"abstract":"In previous studies, natural killer lysin (NK-lysin) emerged as a crucial antimicrobial peptide (AMP) discharged by NK cells and CTLs. The sequence of NK-lysin was cloned and discovered in some fishes, but its function remains unclear. In our study, we obtained a copy of NK-lysin from the spleen of the healthy clownfish (Amphiprion ocellaris; AoNK-lysin) through cloning and proceeded to investigate its potential functions and activities. The findings showed that the AoNK-lysin gene’s open reading frame (ORF) had a length of 465 base pairs (bp) and encoded 154 amino acids (aa), which included a saposin B domain and six cysteine residues that are highly conserved, forming three intrachain disulfide bonds to carry out antimicrobial activity. The AoNK-lysin gene was widely present in different tissues, with the skin showing the highest expression, followed by the eye, intestine, and muscle. Additionally, the expression of AoNK-lysin was significantly upregulated in the immune organs (spleen, gill, intestine, and head kidney) of A. ocellaris after being challenged by Singapore group iridovirus (SGIV). Furthermore, a 399 base pair cDNA sequence that encodes the fully developed peptide of AoNK-lysin was successfully inserted into a secretion plasmid called pPIC9K. Subsequently, a significant amount of the recombinant AoNK-lysin protein was efficiently manufactured using the Pichia pastoris expression system. The antibacterial test demonstrated that the AoNK-lysin protein significantly suppressed the growth of various pathogens, particularly Streptococcus agalactiae, Streptococcus iniae, Salmonella typhi, Shigella sonnei, Pseudomonas aeruginosa, and Aeromonas caviae. The minimal inhibitory concentration (MIC) was found to be 7.81 μg/mL. Further analysis of antiviral assays showed all the viral mRNA of SGIV to be significantly reduced after AoNK-lysin protein stimuli in FHM cells. Collectively, these discoveries indicate that AoNK-lysin exhibits features of both direct pathogen-killing abilities and inhibited virus replication.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"35 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135218921","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}
María Dolores Ayala, Elena Chaves-Pozo, María Isabel Sáez, Alba Galafat, Francisco Javier Alarcón, Tomás Francisco Martínez, Marta Arizcun
Previous studies have shown that Nannochloropsis gaditana can partially replace fishmeal in the diet of gilthead seabream, Sparus aurata. However, its effect on muscle growth is hardly known. This experiment was carried out with gilthead seabream adults that were fed with N. gaditana at two inclusion levels (2.5 or 5%) either raw (R2.5 and R5 groups) or cellulose-hydrolyzed (H2.5 and H5 groups) for 45 days in the final fattening phase. The body length and body weight were measured in all fish at the beginning and end of the experiment. Also, the white muscle transverse area (WM), size, number and fibrillar density of the white fibers were measured in 9 fish group−1. After 45 days, the body parameters and the WM did not show significant differences among the groups. However, muscle cellularity did show significant differences, such that the hypertrophy values were higher in the H2.5 and H5 than in the R2.5 and R5 groups. On the contrary, R2.5 and R5 showed the highest fibrillar density and hyperplasia values, which are often positively correlated with the fillet firmness and therefore could improve the final quality of the fish. No significant differences attributable to the inclusion levels of N. gaditana were observed.
{"title":"Effect on Muscle Cellularity of Diet Supplementation with Nannochloropsis gaditana Microalgae in the Final Fattening Phase of Gilthead Seabream Culture up to Commercial Size","authors":"María Dolores Ayala, Elena Chaves-Pozo, María Isabel Sáez, Alba Galafat, Francisco Javier Alarcón, Tomás Francisco Martínez, Marta Arizcun","doi":"10.3390/fishes8110532","DOIUrl":"https://doi.org/10.3390/fishes8110532","url":null,"abstract":"Previous studies have shown that Nannochloropsis gaditana can partially replace fishmeal in the diet of gilthead seabream, Sparus aurata. However, its effect on muscle growth is hardly known. This experiment was carried out with gilthead seabream adults that were fed with N. gaditana at two inclusion levels (2.5 or 5%) either raw (R2.5 and R5 groups) or cellulose-hydrolyzed (H2.5 and H5 groups) for 45 days in the final fattening phase. The body length and body weight were measured in all fish at the beginning and end of the experiment. Also, the white muscle transverse area (WM), size, number and fibrillar density of the white fibers were measured in 9 fish group−1. After 45 days, the body parameters and the WM did not show significant differences among the groups. However, muscle cellularity did show significant differences, such that the hypertrophy values were higher in the H2.5 and H5 than in the R2.5 and R5 groups. On the contrary, R2.5 and R5 showed the highest fibrillar density and hyperplasia values, which are often positively correlated with the fillet firmness and therefore could improve the final quality of the fish. No significant differences attributable to the inclusion levels of N. gaditana were observed.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135266043","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}
Ann-Christin Ziebell, Maite L. Vogel, Niklas Kjell Ratajczak, Bert W. Hoeksema
Cryptobenthic fishes make up more than half of coral reef fish fauna and contribute greatly to coral reef trophodynamics and diversity. Because of their small size, they are easily overlooked and understudied. Some of them use corals as their habitat, but this association is not well understood. In the Caribbean, two common cryptobenthic gobies, Elacatinus evelynae and Coryphopterus lipernes, are usually observed residing on corals. In order to compare their habitat use, we investigated their distributions on a range of scleractinian host-coral species at three different depths (5, 10, and 15 m) at Curaçao, southern Caribbean. The numbers of both species were relatively low at 5 m. Furthermore, we investigated the relationship between fish size and depth and found that adult E. evelynae individuals were most common at 5 m depth and juveniles at 15 m depth. Novel host corals were found for both fish species. Taking host size into account, the gobies were most abundant on large coral colonies of two host species: E. evelynae on both Colpophyllia natans and Montastraea cavernosa, and C. lipernes only on C. natans. In summary, depth, host species, and host-colony size were found to be environmental factors that may determine the occurrence of both fish species.
{"title":"Habitat Use of Two Coral-Associated Cryptobenthic Gobiid Fishes (Family: Gobiidae) in the Southern Caribbean","authors":"Ann-Christin Ziebell, Maite L. Vogel, Niklas Kjell Ratajczak, Bert W. Hoeksema","doi":"10.3390/fishes8100531","DOIUrl":"https://doi.org/10.3390/fishes8100531","url":null,"abstract":"Cryptobenthic fishes make up more than half of coral reef fish fauna and contribute greatly to coral reef trophodynamics and diversity. Because of their small size, they are easily overlooked and understudied. Some of them use corals as their habitat, but this association is not well understood. In the Caribbean, two common cryptobenthic gobies, Elacatinus evelynae and Coryphopterus lipernes, are usually observed residing on corals. In order to compare their habitat use, we investigated their distributions on a range of scleractinian host-coral species at three different depths (5, 10, and 15 m) at Curaçao, southern Caribbean. The numbers of both species were relatively low at 5 m. Furthermore, we investigated the relationship between fish size and depth and found that adult E. evelynae individuals were most common at 5 m depth and juveniles at 15 m depth. Novel host corals were found for both fish species. Taking host size into account, the gobies were most abundant on large coral colonies of two host species: E. evelynae on both Colpophyllia natans and Montastraea cavernosa, and C. lipernes only on C. natans. In summary, depth, host species, and host-colony size were found to be environmental factors that may determine the occurrence of both fish species.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135367139","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}
Deep-sea cage aquaculture (DSCA) is an important way to expand new space for marine aquaculture, promote the transformation and upgrade of the fishery industry, and optimize the structure of marine aquaculture. Using the panel data of DSCA in China’s coastal areas from 2013 to 2021, this study constructs the SBM–Malmquist model to measure the DSCA production efficiency and analyzes its total factor productivity. The results show that the overall DSCA production efficiency exhibited an increasing trend in spite of a sharp decline in 2019. The efficiency exhibited regional differences, being the strongest in the Bohai Sea region, followed by in the Yellow Sea, the South China Sea, and the East China Sea regions. The overall total factor productivity remained generally stable, although a large fluctuation occurred between 2019 and 2021. Both pure technological efficiency and scale efficiency promoted the total factor productivity in 2019–2021, while the efficiency of technological changes in societal aspects declined. This study shows that the DSCA production efficiency is significantly influenced by input factors such as labor and capital investment. In addition, natural disasters inhibit the improvement of the production efficiency to some extent.
{"title":"Efficiency Analysis of China Deep-Sea Cage Aquaculture Based on the SBM–Malmquist Model","authors":"Ying Zhang, Meng-Fei Li, Xiao-Han Fang","doi":"10.3390/fishes8100529","DOIUrl":"https://doi.org/10.3390/fishes8100529","url":null,"abstract":"Deep-sea cage aquaculture (DSCA) is an important way to expand new space for marine aquaculture, promote the transformation and upgrade of the fishery industry, and optimize the structure of marine aquaculture. Using the panel data of DSCA in China’s coastal areas from 2013 to 2021, this study constructs the SBM–Malmquist model to measure the DSCA production efficiency and analyzes its total factor productivity. The results show that the overall DSCA production efficiency exhibited an increasing trend in spite of a sharp decline in 2019. The efficiency exhibited regional differences, being the strongest in the Bohai Sea region, followed by in the Yellow Sea, the South China Sea, and the East China Sea regions. The overall total factor productivity remained generally stable, although a large fluctuation occurred between 2019 and 2021. Both pure technological efficiency and scale efficiency promoted the total factor productivity in 2019–2021, while the efficiency of technological changes in societal aspects declined. This study shows that the DSCA production efficiency is significantly influenced by input factors such as labor and capital investment. In addition, natural disasters inhibit the improvement of the production efficiency to some extent.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"18 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135411999","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}
Yu Zhang, Lu Qi, Fengping Li, Yi Yang, Zhifeng Gu, Chunsheng Liu, Qi Li, Aimin Wang
The complete mitogenomes of Pinctada albina and Pinctada margaritifera were sequenced in this study, with sizes of 23,841 bp and 15,556 bp, respectively. The mitochondrial genome analysis of eight Pterioidea species indicated the existence of gene rearrangements within the superfamily. The ATP8 gene was not detected in the two new mitogenomes, and rrnS was found to be duplicated in P. albina’s mitogenome. The reconstructed phylogeny based on mitogenomes strongly supported the monophyly of Pterioidea and provided robust statistical evidence of the phylogenetic relationships within Pteriomorphia. The analysis of the mitochondrial gene order revealed that of P. margaritifera to be the same as the ancestral order of Pterioidea. The gene orders of the Pterioidea species were mapped to the phylogenetic tree, and the gene rearrangement events were inferred. These results provide important insights that will support future research, such as studies extending the evolutionary patterns of the gene order from P. margaritifera to other species and determining the evolutionary status of Pterioidea within the infraclass Pteriomorphia.
{"title":"Mitogenomic Analysis of Pterioidea (Bivalvia: Pteriomorphia): Insights into the Evolution of the Gene Rearrangements","authors":"Yu Zhang, Lu Qi, Fengping Li, Yi Yang, Zhifeng Gu, Chunsheng Liu, Qi Li, Aimin Wang","doi":"10.3390/fishes8100528","DOIUrl":"https://doi.org/10.3390/fishes8100528","url":null,"abstract":"The complete mitogenomes of Pinctada albina and Pinctada margaritifera were sequenced in this study, with sizes of 23,841 bp and 15,556 bp, respectively. The mitochondrial genome analysis of eight Pterioidea species indicated the existence of gene rearrangements within the superfamily. The ATP8 gene was not detected in the two new mitogenomes, and rrnS was found to be duplicated in P. albina’s mitogenome. The reconstructed phylogeny based on mitogenomes strongly supported the monophyly of Pterioidea and provided robust statistical evidence of the phylogenetic relationships within Pteriomorphia. The analysis of the mitochondrial gene order revealed that of P. margaritifera to be the same as the ancestral order of Pterioidea. The gene orders of the Pterioidea species were mapped to the phylogenetic tree, and the gene rearrangement events were inferred. These results provide important insights that will support future research, such as studies extending the evolutionary patterns of the gene order from P. margaritifera to other species and determining the evolutionary status of Pterioidea within the infraclass Pteriomorphia.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"9 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135366611","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}
Understanding the spatial distribution of fishing activity and suitable fishing areas is important for improving sustainable fisheries management and protecting vulnerable fish stocks. To identify climate-related habitat changes and variations in the distribution of fishing activity for squid-jigging vessels in the Northwest Pacific Ocean, two types (weighted arithmetic mean method, weighted-AMM; weighted geometric mean method, weighted-GMM) of habitat suitability index (HSI) models were developed in this study with marine environmental data at different depths. The boosted regression tree (BRT) model was adopted to access the monthly important environmental variables and the relative influence of the corresponding variables. The results showed that the weighted-AMM has better prediction performance than the weighted-GMM. The suitable fishing areas showed significant seasonal changes in both spatial location and coverage area. The hotspot map showed that the suitable fishing area for squid-jigging vessels was located in the scope of 42∘ N∼44∘ N, 155∘ E∼170∘ E throughout the year during 2012∼2019, which suggests that high squid-jigging fishing pressure should be given more attention in fishery management. The HSI model also had good prediction performance for the fishery data of Chinese companies, except for June and July. Additionally, fishing efforts could be used as alternative data for fishery research. The study has also suggested that fishery data are restricted by spatial and temporal distribution and fishing experience, which probably biases the results of the research.
{"title":"Evaluating Suitability of Fishing Areas for Squid-Jigging Vessels in the Northwest Pacific Ocean Derived from AIS Data","authors":"Yingjie Fei, Shenglong Yang, Mengya Huang, Xiaomei Wu, Zhenzhen Yang, Jiangyue Zhao, Fenghua Tang, Wei Fan, Sanling Yuan","doi":"10.3390/fishes8100530","DOIUrl":"https://doi.org/10.3390/fishes8100530","url":null,"abstract":"Understanding the spatial distribution of fishing activity and suitable fishing areas is important for improving sustainable fisheries management and protecting vulnerable fish stocks. To identify climate-related habitat changes and variations in the distribution of fishing activity for squid-jigging vessels in the Northwest Pacific Ocean, two types (weighted arithmetic mean method, weighted-AMM; weighted geometric mean method, weighted-GMM) of habitat suitability index (HSI) models were developed in this study with marine environmental data at different depths. The boosted regression tree (BRT) model was adopted to access the monthly important environmental variables and the relative influence of the corresponding variables. The results showed that the weighted-AMM has better prediction performance than the weighted-GMM. The suitable fishing areas showed significant seasonal changes in both spatial location and coverage area. The hotspot map showed that the suitable fishing area for squid-jigging vessels was located in the scope of 42∘ N∼44∘ N, 155∘ E∼170∘ E throughout the year during 2012∼2019, which suggests that high squid-jigging fishing pressure should be given more attention in fishery management. The HSI model also had good prediction performance for the fishery data of Chinese companies, except for June and July. Additionally, fishing efforts could be used as alternative data for fishery research. The study has also suggested that fishery data are restricted by spatial and temporal distribution and fishing experience, which probably biases the results of the research.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135367145","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}
Alexandra Sintori, Vasilia Konstantidelli, Angelos Liontakis, Stamatis Mantziaris, Irene Tzouramani
Fishing contributes significantly to food security and offers employment and income to many coastal communities worldwide. On the other hand, it has been recognized as a dangerous and demanding activity that involves high economic risk and uncertainty as well as outdoor work and interactions with nature, which makes fishing more of a way of life rather than just a way to make a living. Non-monetary attributes of fishing have been reported to affect fishers’ decision-making and management and can explain the resilience and sustainability of the sector, even in difficult economic circumstances that hinder profitability. This study uses multivariate statistical analysis to identify profiles of Greek fishers according to their motives and objectives and to link them to the main demographic and socioeconomic characteristics. Overall, five fisher profiles are identified, including “profit maximizers”, “business-oriented” and “subsistence” fishers. Our analysis indicates that all fishers value the non-monetary attributes of the activity higher than monetary values like profit, though large-scale fishers seem to be more business-oriented than small-scale fishers. The identification and understanding of the objective profiles provide useful insights to researchers, advisors and policymakers regarding fishers’ decision-making and can ultimately lead to more efficient policy design and fisheries management.
{"title":"Is It All about Profit? Greek Fishers’ Motives and Objective Profiles","authors":"Alexandra Sintori, Vasilia Konstantidelli, Angelos Liontakis, Stamatis Mantziaris, Irene Tzouramani","doi":"10.3390/fishes8100527","DOIUrl":"https://doi.org/10.3390/fishes8100527","url":null,"abstract":"Fishing contributes significantly to food security and offers employment and income to many coastal communities worldwide. On the other hand, it has been recognized as a dangerous and demanding activity that involves high economic risk and uncertainty as well as outdoor work and interactions with nature, which makes fishing more of a way of life rather than just a way to make a living. Non-monetary attributes of fishing have been reported to affect fishers’ decision-making and management and can explain the resilience and sustainability of the sector, even in difficult economic circumstances that hinder profitability. This study uses multivariate statistical analysis to identify profiles of Greek fishers according to their motives and objectives and to link them to the main demographic and socioeconomic characteristics. Overall, five fisher profiles are identified, including “profit maximizers”, “business-oriented” and “subsistence” fishers. Our analysis indicates that all fishers value the non-monetary attributes of the activity higher than monetary values like profit, though large-scale fishers seem to be more business-oriented than small-scale fishers. The identification and understanding of the objective profiles provide useful insights to researchers, advisors and policymakers regarding fishers’ decision-making and can ultimately lead to more efficient policy design and fisheries management.","PeriodicalId":12405,"journal":{"name":"Fishes","volume":"28 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135462909","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：