Fish Physiology and Biochemistry最新文献

{"title":"Loss of responses to odorants and pheromones in mPRγ (paqr5b)-knockout zebrafish.","authors":"Md Ekramul Hasan, Saokat Ahamed, Mohammad Maksudul Hassan, Mohammad Tohidul Amin, Umme Habiba Mustary, Toshinobu Tokumoto","doi":"10.1007/s10695-025-01563-2","DOIUrl":"https://doi.org/10.1007/s10695-025-01563-2","url":null,"abstract":"<p><p>In our previous study, we generated a membrane-type progesterone receptor γ (paqr5b) knockout zebrafish line. Knocking out paqr5b by genome editing resulted in the loss of neurons in the olfactory rosette (OR). These findings indicated that Paqr5b plays an essential role in the formation of olfactory neurons. In this study, we investigated the extent to which paqr5b^-/- fish lacking olfactory neurons retain their sense of smell. We used a reported tank for zebrafish olfactory analysis with a dividing plate in the middle. The tank was divided into three zones: the right zone, where test substances were added; the neutral zone; and the left zone. The fish were released into the neutral zone at the beginning of each test, the chemical was added to the corner of the right zone, and a 3-min video was taken to track the movements of the fish. The video was then played back, and the time spent in the three zones was counted manually. Both male and female paqr5b^+/+ and paqr5b^-/- zebrafish were separately analyzed for time spent in the three zones after exposure to ATP, cadaverine, and the pheromone 17α,20β-dihydroxy-4-pregnen-3-one (DHP). Both male and female paqr5b^+/+ zebrafish were strongly attracted to ATP and stayed in the right zone for approximately 2 min (67%). In addition, paqr5b^+/+ zebrafish avoided cadaverine and stayed longer in the left zone than in any other zone. In contrast, paqr5b^-/- zebrafish stayed in all three zones for approximately the same amount of time, even after exposure to ATP and cadaverine. The paqr5b^+/+ fish were attracted to DHP and stayed in the right zone longer. Paqr5b^-/- zebrafish of either sex were not reactive to DHP exposure. These results showed that paqr5b^-/- zebrafish lacking olfactory neurons lost responsiveness to odorants and pheromones.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 5","pages":"152"},"PeriodicalIF":2.5,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12397192/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Induced swimming reduced stress and modulated immune response and antioxidant status in juvenile rainbow trout (Oncorhynchus mykiss).","authors":"Carlos Espírito-Santo, Carmen Alburquerque, Thaís Cavalheri, Francisco A Guardiola, Rodrigo O A Ozório, Leonardo J Magnoni","doi":"10.1007/s10695-025-01569-w","DOIUrl":"https://doi.org/10.1007/s10695-025-01569-w","url":null,"abstract":"<p><p>Promoting swimming in aquaculture has been proposed to enhance fish welfare. This study investigated the effects of 6 h of swimming on stress, immune, metabolic, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss). Fish (n = 8) were individually subjected to one of four experimental conditions: minimal water flow (control, < 0.1 body-lengths (BL)·s⁻¹); low-speed (L, 0.8 BL·s⁻¹); high-speed (H, 2.3 BL·s⁻¹); and oscillating speeds (O, 0.8/2.3 BL·s⁻¹). Plasma cortisol levels were lower in swimming groups (L, H, O) than that in the control group, indicating reduced stress. Lysozyme and peroxidase activities increased in skin mucus of fish from L and H groups, reflecting enhanced mucosal immunity. Expression of cytokines (tnfα, il1β), inflammation modulators (nfκb1), and immune-related (lyz, ctsd) genes in head-kidney, gills, and heart did not vary among groups. In red muscle, increased citrate synthase activity across swimming conditions reflected enhanced aerobic metabolism, while cytochrome c oxidase activity was higher in fish from H and O groups, indicating elevated mitochondrial oxidative capacity. Lactate dehydrogenase activity was higher in red muscle in the O group, reflecting greater reliance on anaerobic metabolism under oscillating swimming. Increased GSH/GSSG ratio in red and white muscle of L and H groups indicated improved antioxidant status. Nonetheless, higher lipid peroxidation levels in the liver suggest increased oxidative stress in the O group, indicating that oscillating swimming may impose metabolic and oxidative challenges. Results show that short-term induced steady swimming under L and H conditions could be used beforehand when applying procedures that decrease welfare in farmed rainbow trout, such as handling or transport, aiming to reduce stress, improving immune and antioxidant responses.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 5","pages":"151"},"PeriodicalIF":2.5,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12394289/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"White poplar leaves dietary intervention mitigates hexaflumuron toxicity on growth, neuro-behavioral status, autophagy-related gene expression, and histopathological changes in Nile tilapia.","authors":"Rowida E Ibrahim, Mohammed S Sobh, Asmaa I Abdelaty, Abdallah Tageldein Mansour, Ahmed S AlSaqufi, Yousef Alkhamis, Hesham A Hassanien, Ahmed Abbas, Tarek Khamis, Afaf N Abdel Rahman","doi":"10.1007/s10695-025-01561-4","DOIUrl":"https://doi.org/10.1007/s10695-025-01561-4","url":null,"abstract":"<p><p>Pesticide pollution of waterways is a significant problem that compromises the sustainability of aquaculture and harms the health of wild fish. The restoration potential of dietary white poplar leaves (WPL) during long-term hexaflumuron (HEX) exposure in Nile tilapia (Oreochromis niloticus) was studied for 60 days on growth, physiological, behavioral, gene expression, and histopathology assays. Two hundred fish (36.37 ± 0.15 g) were split into four equal groups, each having five replicates. The CONT (control) and WPL groups received basal diets fortified with 0 and 6 g WPL/kg, respectively, and were not treated with HEX. In contrast, the HEX and WPL + HEX groups received the same feeding as the CONT and WPL groups, respectively, and were treated with 0.72 mg/L HEX. The results showed that HEX exposure inhibited growth, induced behavioral alterations, and increased brain 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. However, the activity of acetylcholine esterase (AChE) did not significantly differ due to HEX exposure. HEX toxicity induced histopathological changes in the brain tissue, including pyknotic neurons, satellitosis, and gliosis. Additionally, the shortening of numerous secondary gill filaments and congested gill capillaries within some primary filaments was observed due to HEX exposure. The brain expression of the target of rapamycin, phosphoinositide 3-kinase, and V-akt murine thymoma viral oncogene homolog genes was upregulated, and the microtubule-associated protein light chain kinase 3 gene was downregulated due to HEX exposure. Upregulation of the ubiquitin-binding protein gene and downregulation of Beclin-1 and autophagy-related gene-12 were detected in the gills of the HEX fish with a high mortality rate (24%). Feeding on the WPL diet improved growth and behaviors and reduced brain 8-OHdG levels and mortality (10%). Furthermore, the WPL diet restored the histological picture of the brain and gill tissues and improved the autophagy process of the HEX-exposed fish. Collectively, the WPL diet could be used for the mitigation of the hazardous impacts of HEX toxicity in Nile tilapia. This could enhance our insight into the HEX toxicity mechanism and the protection offered by WPL.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 5","pages":"150"},"PeriodicalIF":2.5,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948334","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":"Dietary taurine improves antioxidant and lysozyme activity, carbohydrate-related metabolism, and digestive genes expression of longfin yellowtail (Seriola rivoliana).","authors":"Marco A Hernández-de Dios, Minerva C Maldonado-García, Deneb Maldonado-García, Laura T Guzmán-Villanueva, Dariel Tovar-Ramírez","doi":"10.1007/s10695-025-01566-z","DOIUrl":"https://doi.org/10.1007/s10695-025-01566-z","url":null,"abstract":"<p><p>Taurine is an amino acid widely present in animal tissues. Recent research has highlighted the importance of including taurine in the diet of various commercially relevant species. This study evaluated the impact of taurine supplementation in the diet of Seriola rivoliana on the activity of antioxidant enzymes, lysozyme, and the expression of metabolic-related genes in different tissues. Three experimental diets were designed with 0% (Control), 1%, and 2% of taurine concentrations, administered over 60 days. The results indicated that taurine supplementation significantly improved the activity of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and myeloperoxidase (MPO) in the liver and plasma. Additionally, an increase in lysozyme (LZM) activity was observed in mucus and plasma of the fish. Regarding gene expression, the 2% taurine supplementation significantly increased the expression of critical genes involved in carbohydrates and lipid metabolism, such as glucokinase (gck), hexokinase (hk1), and acetyl-CoA carboxylase (acoa1) in the liver, as well as lipase (lpl), cholecystokinin (cck), and trypsin (try1) in the intestine. These results suggest that taurine not only enhances the antioxidant and immune capacity of the fish but also optimizes their energy metabolism and digestion, which could contribute to improved aquaculture diets, promoting more excellent resistance to oxidative stress and better overall health of fish raised under intensive conditions.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 5","pages":"149"},"PeriodicalIF":2.5,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948282","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":"Effects of dietary fishmeal replacement with Periplaneta americana meal on growth, antioxidant activity, and immunity of juvenile largemouth bass, Micropterus salmoides.","authors":"Yong Huang, Yuanyi Liu, Changchang Pu, Zihui Wei, Weichuan Zhang, Hongyu Chen","doi":"10.1007/s10695-025-01558-z","DOIUrl":"10.1007/s10695-025-01558-z","url":null,"abstract":"<p><p>At present, the aquaculture industry is experiencing a significant rise in fishmeal (FM) demand due to the growth of breeding scale and factory aquaculture, which seriously impedes the sustainable development of aquaculture. Insect meal has become a key option for partially substituting FM in aquafeed. The study investigated how substituting FM with (Periplaneta americana meal (PAM) impacts the growth performance, body composition, antioxidant activities, digestive enzyme activity, and immunity in juvenile largemouth bass (JLMB). Four hundred and fifty JLMB, averaging 16.71 ± 0.09 g in starting weight, were selected for an 8-week feeding experiment. The experimental diets were prepared by substituting FM in the basal diet with PAM at five concentration levels: 0% (P0, control), 5% (P5), 10% (P10), 15% (P15), and 20% (P20). Results showed that weight gain rate (WGR) and specific growth rate (SGR) were not significantly different among JLMB across all experimental groups (P > 0.05). In P20, a significant increase in the feed conversion ratio (FCR) was observed, along with a significant decrease in the viscerosomatic index (VSI) (P < 0.05). As the concentration of PAM increased, a significant decrease in the hepatosomatic index (HSI) was observed (P < 0.05). The activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the liver and gut were significantly elevated compared to those in P0 (P < 0.05). The intestinal morphological structure exhibited no significant alterations (P > 0.05). The activities of pepsin and lipase in the intestines significantly increased with the increasing concentration of PAM (P < 0.05). In comparison with P0, P15 had significantly lower expression of IL-8 and TNF-α (P < 0.05), yet significantly higher expression of IL-10 and HIF-1α (P < 0.05). Collectively, our study demonstrated that using PAM as a substitute for FM did not have a negative impact on the growth of JLMB and improved antioxidant activity and immune response.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 5","pages":"148"},"PeriodicalIF":2.5,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144872195","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":"Acute co-exposure to microbeads and cadmium enhances accumulation and alters plasma biochemical markers and stress indicators in Korean rockfish, Sebastes schlegeli.","authors":"Young Hoon Kwon, Jin A Kim, Jun-Hwan Kim, Cheol Young Choi","doi":"10.1007/s10695-025-01559-y","DOIUrl":"10.1007/s10695-025-01559-y","url":null,"abstract":"<p><p>Microplastics (MPs), including microbeads (MBs) and heavy metals such as cadmium (Cd), are persistent marine pollutants that can interact synergistically, with MPs facilitating metal adsorption and transportation. Korean rockfish, an important commercial species, inhabits coastal waters and is susceptible to various external pollutants. In this study, we aimed to assess the effects of co-exposure to MBs and Cd on the accumulation of these contaminants and physiological stress responses in Korean rockfish. Juvenile Korean rockfish were exposed to either a control, single treatments of MBs (5 beads/L [MB5] or 50 beads/L [MB50]) or Cd (0.2 mg/L [Cd0.2] or 0.4 mg/L [Cd0.4]), or their combined treatments (MB5 + Cd0.2, MB5 + Cd0.4, MB50 + Cd0.2, and MB50 + Cd0.4) for 5 days. After exposure, MBs and Cd accumulations in the gill and intestine were significantly higher in the MB50 + Cd0.4 than those in the other combined-exposure groups at all time points (p < 0.05 for all). Compared with the control treatment, the combined treatments significantly increased the levels of plasma glucose, aspartate transaminase, and alanine transaminase, and mRNA expression of heat shock protein 70 and metallothionein in the liver (p < 0.05 for all), with the MB50 + Cd0.4 treatment exhibiting the highest values for most parameters. Comet assays also showed significantly increased DNA damage in combined-exposure groups compared with those in single-exposure groups (p < 0.05 for all). These findings highlight that co-exposure to MBs and Cd enhances Cd bioaccumulation, toxicity, and DNA damage, underscoring the risks associated with marine pollutant mixtures and their implications for environmental monitoring and coastal management.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 5","pages":"147"},"PeriodicalIF":2.5,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144859072","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":"Thyme-synthesized silver nanoparticles mitigate immunosuppression, oxidative damage, and histopathological alterations induced by multidrug-resistant Enterococcus faecalis in Oreochromis niloticus: in vitro and in vivo assays.","authors":"Dalia A Abdel-Moneam, Hanan S Khalefa, Maha M Rashad, Ghada E Ali, Yasmine H Ahmed, Eman Ragab, Osama A Fouad, Ramadan A Geioushy, Sahr B Mahmoud","doi":"10.1007/s10695-025-01560-5","DOIUrl":"10.1007/s10695-025-01560-5","url":null,"abstract":"<p><p>The escalating prevalence of antibiotic resistance poses a significant challenge to controlling aquatic diseases, underscoring the need for innovative antimicrobial approaches. Therefore, the current study aimed to investigate the effects of thyme-synthesized silver nanoparticles (thyme-AgNPs) on modulating the immunosuppressive, oxidative stress, and histopathological changes induced by multidrug-resistant Enterococcus faecalis (MDR E. faecalis) infection in Oreochromis niloticus (Nile tilapia). The antibiotic susceptibility profiling of the isolated E. faecalis (PQ084785) revealed resistance to multiple antibiotic classes. The in vitro bactericidal efficacy of thyme-AgNPs was confirmed, with minimum bactericidal concentrations (MBC) and minimum inhibitory concentrations (MIC) of 62.5 µg/mL and 31.5 µg/mL, respectively. In vivo, the 96-h median lethal concentration (LC₅₀) of thyme-AgNPs was determined to be 1 mg/L. Meanwhile, eighty O. niloticus (30.00 ± 5.00 g) were categorized into four groups in duplicate: group I was the negative control group, group II was intraperitoneally injected with MDR E. faecalis (0.2 mL of 0.79 × 10⁸ CFU/mL), group III was exposed to the sublethal dose of thyme-AgNPs in water (0.1 mg/L), and group IV was challenged with the E. faecalis and exposed to thyme-AgNPs simultaneously for 15 days. Results outlined that E. faecalis induced clinical abnormalities, reduced immunoglobulin M levels, elevated oxidant indicators (malondialdehyde), decreased antioxidant capacity (reduced glutathione content, catalase, and superoxide dismutase), and significantly upregulated immune gene expression (tumor necrosis factor-α and interleukin-1β) with marked histopathological and histochemical alterations in gill and liver tissues. Interestingly, the thyme-AgNPs intervention resulted in a noticeable improvement in all measured biomarkers as well as histopathological regeneration. Overall, thyme-AgNPs are a recent antibacterial tool against immune-oxidant/antioxidant and histopathological changes triggered by MDR E. faecalis infection.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 4","pages":"146"},"PeriodicalIF":2.5,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12356727/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144855040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protective effect of selenium supplementation against damage of health and muscle quality in Onychostoma macrolepis under a thermally oxidized fish oil-enriched diet.","authors":"Yangfen Xing, Ping Wang, Shengke Wen, Mingyue Zhang, Enric Gisbert, Marijana Todorcevic, Jishu Zhou","doi":"10.1007/s10695-025-01562-3","DOIUrl":"10.1007/s10695-025-01562-3","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Fish oil is rich in highly unsaturated fatty acids such as EPA and DHA, which are easily oxidized, while selenium is an essential micronutrient that contributes to antioxidant defense by forming selenoproteins involved in maintaining cellular homeostasis. In this study, to explore the effects of selenium (selenium-rich black bean dregs; SeB) on the growth, health status, and muscle quality of Onychostoma macrolepis (O. macrolepis) under a thermally oxidized fish oil-enriched diet, a total of 156 O. macrolepis (3.43 ± 0.25 g/fish) were divided into four groups (triplicate per group) and fed with four isonitrogenous (386.7 g/kg) and isolipidic (91.7 g/kg) diets: fresh fish oil (FFO), oxidized fish oil (OFO), oxidized fish oil supplemented with selenium (1.48 mg Se/kg diet; selenium-rich yeast; OFOSeY), and oxidized fish oil supplemented with selenium (1.48 mg Se/kg diet; selenium-rich black bean dregs; OFOSeB) respectively, in a recirculation aquaculture system for 60 days. The results showed that the HSI (hepatosomatic index) was the highest in the OFO group, and it significantly decreased in selenium supplementation groups (OFOSeB and OFOSeY; P &lt; 0.05). The proximate composition, selenium content, and amino acid composition of the muscle in four groups were not significantly different (P &gt; 0.05). The fatty acid content of 18:0, 18:1n-7, 20:3n-6, 20:5n-3, 22:5n-3, 22:6n-3, and n-3 PUFA were significantly reduced in the muscle of the OFO group compared to the FFO group (P &lt; 0.05), and they were recovered in selenium supplementation groups (OFOSeB and OFOSeY; P &lt; 0.05). The serum ALT (aspartate aminotransferase), TG (triglyceride), and MDA (malondialdehyde) were the highest in the OFO group, and they were recovered in selenium supplementation groups (OFOSeB and OFOSeY; P &lt; 0.05). The structure of hepatocytes, intestine, muscle, and intraperitoneal adipocyte, including the hepatopancreas mitochondria, the intestinal villi, and muscle fibers showed abnormalities in the OFO group, and the supplementation of selenium (OFOSeB and OFOSeY) showed recovery. The abundance of the intestinal bacteria of the O. macrolepis was adversely affected by OFO (Proteobacteria significantly increased and Actinomycetes significantly decreased), and the supplementation of selenium recovered it to a healthier state. The relative gene expression of sod, gpx, and cat were not significantly different between FFO and OFO groups, while they significantly increased in the selenium supplementation group of OFOSeY (P &lt; 0.05). The metabolomics results showed that there were significant differences in 23 metabolites between the OFO and OFOSeB groups (P &lt; 0.05), which were significantly involved in the pathway of sphingolipid metabolism, histidine metabolism, fructose and mannose metabolism, and fatty acid biosynthesis (P &lt; 0.05). In summary, the present results indicated the protective effect of selenium supplementation against injury to health in hepatopancreas, intestine, and","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 4","pages":"144"},"PeriodicalIF":2.5,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144855039","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":"Yellowtail kingfish Seriola aureovittata farmed in offshore net cage response to high density by regulating protein and glucose metabolism.","authors":"Yan Jiang, Yongjiang Xu, Chaoyong Yu, Aijun Cui, Kaijie Wang, Bin Wang, Zhiyong Xue","doi":"10.1007/s10695-025-01556-1","DOIUrl":"10.1007/s10695-025-01556-1","url":null,"abstract":"<p><p>We evaluated the impact of stocking density on the growth performance and physiological parameters of 1-year-old yellowtail kingfish (Seriola aureovittata) farmed in offshore net cages. A 90-day experiment was conducted with high (HSD, 7.41 ind/m³), medium (MSD, 5.93 ind/m³), and low (LSD, 4.44 ind/m³) stocking densities. Results showed that weight gain rate (WGR) and specific growth rate (SGR) were decreased with increase in density. Serum adrenaline, cortisol, and glucose levels and SOD and LZM activities were all increased with increase in density, and there were significant differences between HSD and MSD. HSD upregulated immune-related gene mRNA levels and activated the cytokine-cytokine receptor interaction pathway. These findings suggest that the fish in HSD suffered from crowding stress and exhibited immune stress, and the fish accelerated protein catabolism and phosphoenolpyruvate metabolism through significantly increasing AST, ALT, and PK activities to obtain more energy and cope with this stress. Meantime, the fish in HSD and MSD significantly downregulated gck expression and upregulated g6pc2 expression in glycolysis/gluconeogenesis to support the elevation of serum glucose levels. The fish in MSD experienced endoplasmic reticulum (ER) stress, which ultimately triggered the ER-associated degradation to restore the normal physiological function of ER. Considering the non-significant difference in AST, ALT, LZM, and PK activities between MSD and LSD, it is speculated that the stress level in MSD is lower than that in HSD. Interestingly, growth-related gene mRNA levels and K value in MSD were higher than those in HSD and LSD, indicating that the fish in MSD have greater growth potential. In this study, an MSD (5.93 ind/m³) was appropriate for 1-year-old yellowtail kingfish farmed in offshore net cages based on welfare and growth performance. These findings provide a technical foundation for the stocking regulation and healthy culture of yellowtail kingfish farmed in net cages.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 4","pages":"145"},"PeriodicalIF":2.5,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144855041","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":"Dietary succinic acid mitigates adverse effects of starch high-starch diet in largemouth bass (Micropterus salmoides) through gut-liver axis modulation.","authors":"Yangyang Liu, Manxia Cao, Jianmin Zhang, Xuan Wang, Ming Jiang, Feng Huang, Ke Cheng, Lixue Dong, Di Peng, Juan Tian","doi":"10.1007/s10695-025-01557-0","DOIUrl":"10.1007/s10695-025-01557-0","url":null,"abstract":"<p><p>A 10-week feeding trial was conducted to investigate the effects of succinic acid (SUA) supplementation in high-starch diets (HSD) on growth and enterohepatic health of largemouth bass (Micropterus salmoides; initial weight 11.96 ± 0.71 g). Six isocaloric and isolipidic diets were formulated, comprising a standard diet containing 10% corn starch and 40% fish meal, an HSD with 15% corn starch and 36% fish meal, and HSDs supplemented with 0.5%, 1.0%, 1.5%, and 2.0% SUA. Compared to standard diet, HSD exhibited adverse effects including impaired feed utilization, growth retardation, diminished antioxidant capacity, and immune response, along with metabolic dysregulation and gut microbiota disturbances. Significant linear and quadratic dose-responses were detected for multiple parameters: feed conversion ratio, hepatosomatic index, viscerosomatic index, glycogen content, amylase and protease activities, and hepatic antioxidant status. The 0.5% SUA supplementation group demonstrated enhanced intestinal morphology, upregulated expression of tight junction proteins (ZO-1 and Claudin-4) and antiapoptotic Bcl2, increased abundance of beneficial microbiota and suppressed endoplasmic reticulum stress markers (GRP78, PERK, IRE1, ATF6, eIF2α, and Chopα). Additionally, dietary 0.5% SUA upregulated hepatic anti-inflammatory mediators (Nrf2, TGFβ1, and IL10), glycolytic genes (PK, PFKL2, and GK), β-oxidation-related CPT1, antiapoptotic Bag, and glucose transporter GLUT2, while downregulating proinflammatory TNFα, gluconeogenic enzymes (PEPCK and G6Pase), lipogenic genes (ACC1 and FASN), and proapoptotic Bad. Broken-line regression analysis identified 0.46-0.50% as the optimal SUA inclusion level based on growth parameters. This study demonstrates that appropriate SUA supplementation alleviates HSD-induced oxidative stress, enhances intestinal barrier function, modulates gut microbiota, and maintains metabolic homeostasis, thereby improving starch utilization and growth performance.</p>","PeriodicalId":12274,"journal":{"name":"Fish Physiology and Biochemistry","volume":"51 4","pages":"142"},"PeriodicalIF":2.5,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144834674","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}