Pub Date : 2026-01-01Epub Date: 2026-03-04DOI: 10.1007/s10641-026-01822-y
Bradley van Zyl, Matthew J Burnett, Celine Hanzen, Colleen T Downs
In South Africa, a water-scarce country, the construction of dams and weirs is increasing to ensure water security for a growing nation. The human need for this infrastructure is generally prioritised over its environmental impact, particularly for aquatic fauna with migratory needs. Such infrastructure can block migratory pathways for fish, trap sediment, and alter river flow regimes. The Lower Thukela Bulk Water Supply Scheme (LTBWSS) abstraction weir was constructed on the lower uThukela River in KwaZulu-Natal Province, South Africa, in 2017, near the town of Mandini. The riverine stretch where it is constructed is a critical interface for marine, estuarine, and freshwater migrant local fish species. As such, a vertical-slot fishway was incorporated into its design to facilitate the movement of fish over the weir. This study utilised data collected from field surveys at three sites upstream of the weir, four sites downstream of it, and two sites on the Mandini Stream, a tributary of the uThukela, to assess the impact of the weir on local fish community structures. Multivariate statistical analyses were employed to identify the environmental variables influencing fish community structures and select fish species in the region. The results showed that the dominant cover types, dominant substrate, average depth, and water temperature significantly affected fish communities in the study. Individual species were driven by different habitats, water velocity-depth profiles, and physical water-quality variables. Furthermore, the presence of the LTBWSS has influenced three cichlid species, particularly Tilapia sparrmanii, which was previously shown to favour silt substrate. The resulting loss of downstream sedimentation because of the LTBWSS weir has led to the absence of the species, along with synergistic effects on water quality and quantity in the downstream sections of the uThukela River.
Supplementary information: The online version contains supplementary material available at 10.1007/s10641-026-01822-y.
{"title":"A fragmented fish community: evaluation of the present distribution and drivers of fish communities in the lower uThukela River, KwaZulu-Natal, South Africa.","authors":"Bradley van Zyl, Matthew J Burnett, Celine Hanzen, Colleen T Downs","doi":"10.1007/s10641-026-01822-y","DOIUrl":"10.1007/s10641-026-01822-y","url":null,"abstract":"<p><p>In South Africa, a water-scarce country, the construction of dams and weirs is increasing to ensure water security for a growing nation. The human need for this infrastructure is generally prioritised over its environmental impact, particularly for aquatic fauna with migratory needs. Such infrastructure can block migratory pathways for fish, trap sediment, and alter river flow regimes. The Lower Thukela Bulk Water Supply Scheme (LTBWSS) abstraction weir was constructed on the lower uThukela River in KwaZulu-Natal Province, South Africa, in 2017, near the town of Mandini. The riverine stretch where it is constructed is a critical interface for marine, estuarine, and freshwater migrant local fish species. As such, a vertical-slot fishway was incorporated into its design to facilitate the movement of fish over the weir. This study utilised data collected from field surveys at three sites upstream of the weir, four sites downstream of it, and two sites on the Mandini Stream, a tributary of the uThukela, to assess the impact of the weir on local fish community structures. Multivariate statistical analyses were employed to identify the environmental variables influencing fish community structures and select fish species in the region. The results showed that the dominant cover types, dominant substrate, average depth, and water temperature significantly affected fish communities in the study. Individual species were driven by different habitats, water velocity-depth profiles, and physical water-quality variables. Furthermore, the presence of the LTBWSS has influenced three cichlid species, particularly <i>Tilapia sparrmanii,</i> which was previously shown to favour silt substrate. The resulting loss of downstream sedimentation because of the LTBWSS weir has led to the absence of the species, along with synergistic effects on water quality and quantity in the downstream sections of the uThukela River.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s10641-026-01822-y.</p>","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"109 1","pages":"54"},"PeriodicalIF":1.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12960327/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147376517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research aimed to examine the combined influence of Astragalus polysaccharide (APS) and Isatis indigotica extract (IIE) dietary supplements on oxidative-inflammatory status, cellular homeostasis, and intestinal integrity in large yellow croaker (Larimichthys crocea). Three replicates of experimental fish (n = 160) received one of five dietary regimens: a basal control (CON) diet, the CON diet containing 0.1% APS (AP), and the AP diet supplemented with 0.05%, 0.1%, and 0.15% IIE (AI1, AI2, and AI3) for 8 weeks. The combined supplements, particularly in the AI2 group, significantly improved intestinal morphology and enhanced the activities of key digestive enzymes. Gene expression analysis revealed that the APS-IIE combination consistently upregulated the intestinal mRNA abundance of major tight junction proteins (CLDN4, OCLN, ZO1, ZO2) compared to the CON or AP groups. Liver antioxidant capacity was strengthened (enhanced CAT capacity), as evidenced by a significant reduction in lipid peroxidation (MDA) levels. In the head kidney, the combination downregulated the expression of pro-inflammatory cytokines (IL8, TNF) and toll-like receptors (TLR1, TLR2, TLR5), and promoted the expression of anti-inflammatory cytokines (IL10, TGFB1). Furthermore, dietary supplementation modulated the crosstalk between autophagy and apoptosis, indicated by altered expression of key marker genes (e.g., increased MAP1LC3B and decreased CASP3/8/9). In conclusion, the simultaneous inclusion of APS and IIE in diets promotes intestinal health, strengthens antioxidant status, and alleviates inflammatory responses, with the 0.1% APS + 0.1% IIE (AI2) formulation demonstrating the most pronounced benefits.
{"title":"Effects of Astragalus Polysaccharide and Isatis indigotica Extract Synergy on the Antioxidant Status, Inflammation, Autophagy, Apoptosis, and Intestinal Health of Larimichthys crocea Juveniles","authors":"Zhichu Chen, Chao Zeng, Ai Wang, Huiyu Wang, Xin Zhi, Zhengbang Chen, Huiyuan Lv, Qiong Qi, Pan Wang, Jianchun Shao, Xinhua Chen","doi":"10.3390/fishes10110593","DOIUrl":"https://doi.org/10.3390/fishes10110593","url":null,"abstract":"This research aimed to examine the combined influence of Astragalus polysaccharide (APS) and Isatis indigotica extract (IIE) dietary supplements on oxidative-inflammatory status, cellular homeostasis, and intestinal integrity in large yellow croaker (Larimichthys crocea). Three replicates of experimental fish (n = 160) received one of five dietary regimens: a basal control (CON) diet, the CON diet containing 0.1% APS (AP), and the AP diet supplemented with 0.05%, 0.1%, and 0.15% IIE (AI1, AI2, and AI3) for 8 weeks. The combined supplements, particularly in the AI2 group, significantly improved intestinal morphology and enhanced the activities of key digestive enzymes. Gene expression analysis revealed that the APS-IIE combination consistently upregulated the intestinal mRNA abundance of major tight junction proteins (CLDN4, OCLN, ZO1, ZO2) compared to the CON or AP groups. Liver antioxidant capacity was strengthened (enhanced CAT capacity), as evidenced by a significant reduction in lipid peroxidation (MDA) levels. In the head kidney, the combination downregulated the expression of pro-inflammatory cytokines (IL8, TNF) and toll-like receptors (TLR1, TLR2, TLR5), and promoted the expression of anti-inflammatory cytokines (IL10, TGFB1). Furthermore, dietary supplementation modulated the crosstalk between autophagy and apoptosis, indicated by altered expression of key marker genes (e.g., increased MAP1LC3B and decreased CASP3/8/9). In conclusion, the simultaneous inclusion of APS and IIE in diets promotes intestinal health, strengthens antioxidant status, and alleviates inflammatory responses, with the 0.1% APS + 0.1% IIE (AI2) formulation demonstrating the most pronounced benefits.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 11","pages":"593-593"},"PeriodicalIF":0.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/11/593/pdf?version=1763525170","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147331234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the feeding mechanisms and interspecific coexistence of sharks is crucial for effective conservation. This study conducted stable isotope analysis on muscle and liver samples from 449 individuals of eight common bycatch shark species collected via bottom trawling in the northern South China Sea (NSCS). Results revealed significant differences in δ13C and δ15N values among species and tissue types. Scoliodon laticaudus exhibited the highest trophic position (TPmuscle = 4.60 ± 0.33; TPliver = 4.53 ± 0.29), while Apristurus platyrhynchus had the lowest (TPmuscle = 2.97 ± 0.44; TPliver = 2.75 ± 0.53). Muscle and liver isotopic signals were consistent, but δ13C differences indicated distinct carbon sources, with Carcharhinus sorrah linked to deep-sea organic matter and S. laticaudus to coastal inputs. Significant correlations between δ13C/δ15N and body length in A. platyrhynchus and Cephaloscyllium fasciatum suggest ontogenetic shifts in diet and habitat toward deeper waters. Trophic niche analysis using corrected standard ellipse area (SEAc) showed Halaelurus burgeri with the widest trophic niche (SEAc > 1.7‰2), reflecting a broad diet, while C. fasciatum had the narrowest (SEAc < 0.3‰2), indicating specialized feeding. Additionally, H. burgeri and C. sarawakensis exhibited significant niche differentiation, reducing interspecific competition, whereas C. fasciatum and Squalus megalops showed high niche overlap, suggesting intense resource competition. The narrower liver niche of C. sarawakensis may reflect recent habitat constriction due to bottom trawling. This study elucidates the feeding ecology and habitat resource utilization of NSCS sharks, providing a scientific basis for effective conservation strategies for shark populations in the region.
{"title":"Multi-Tissue Stable Isotope Analysis Reveals the Feeding Ecology of Dominant Shark Bycatch Species in the Northern South China Sea","authors":"Kui Zhang, Pengli Xiong, Zuozhi Chen, Youwei Xu","doi":"10.3390/fishes10110583","DOIUrl":"https://doi.org/10.3390/fishes10110583","url":null,"abstract":"Understanding the feeding mechanisms and interspecific coexistence of sharks is crucial for effective conservation. This study conducted stable isotope analysis on muscle and liver samples from 449 individuals of eight common bycatch shark species collected via bottom trawling in the northern South China Sea (NSCS). Results revealed significant differences in δ13C and δ15N values among species and tissue types. Scoliodon laticaudus exhibited the highest trophic position (TPmuscle = 4.60 ± 0.33; TPliver = 4.53 ± 0.29), while Apristurus platyrhynchus had the lowest (TPmuscle = 2.97 ± 0.44; TPliver = 2.75 ± 0.53). Muscle and liver isotopic signals were consistent, but δ13C differences indicated distinct carbon sources, with Carcharhinus sorrah linked to deep-sea organic matter and S. laticaudus to coastal inputs. Significant correlations between δ13C/δ15N and body length in A. platyrhynchus and Cephaloscyllium fasciatum suggest ontogenetic shifts in diet and habitat toward deeper waters. Trophic niche analysis using corrected standard ellipse area (SEAc) showed Halaelurus burgeri with the widest trophic niche (SEAc > 1.7‰2), reflecting a broad diet, while C. fasciatum had the narrowest (SEAc < 0.3‰2), indicating specialized feeding. Additionally, H. burgeri and C. sarawakensis exhibited significant niche differentiation, reducing interspecific competition, whereas C. fasciatum and Squalus megalops showed high niche overlap, suggesting intense resource competition. The narrower liver niche of C. sarawakensis may reflect recent habitat constriction due to bottom trawling. This study elucidates the feeding ecology and habitat resource utilization of NSCS sharks, providing a scientific basis for effective conservation strategies for shark populations in the region.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 11","pages":"583-583"},"PeriodicalIF":0.0,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/11/583/pdf?version=1763029999","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eric Yin, Manwen Zeng, Haipeng Yan, Jiahao Gao, Zuchun Chen, Ning Zhang, Yusong Guo, Zhongduo Wang, Zhongdian Dong
Tetramethyl bisphenol A (TMBPA), a novel alternative to Bisphenol A, is widely used as an industrial flame retardant and a raw material for tetramethyl polycarbonate plastics. With the increasing use of TMBPA, its aquatic ecological risks remain unclear. Therefore, this study investigated the developmental toxicity of TMBPA using zebrafish (Danio rerio) as a model, exposing embryos to 0.5, 5, 50, and 200 μg/L TMBPA for 120 h. The results showed that treatment with 5, 50, and 200 μg/L TMBPA decreased the hatching rate of zebrafish embryos at 48 h post-fertilization (hpf), while no significant difference was observed at 72 hpf. Meanwhile, TMBPA exposure at all concentrations showed no significant effect on the survival rate. Furthermore, a high concentration of TMBPA (200 μg/L) significantly reduced the total length and suppressed swimming ability in zebrafish larvae. In addition, gene expression analysis revealed impacts on antioxidant system (cat, gpx, mn-sod, keap1, ucp2, nrf2), hypothalamic–pituitary–thyroid (HPT) axis (ttr, ugt1ab, trβ), cardiac developmental (tbx2b, myl7, bmp4, notch1b, amhc), and the hypothalamic–pituitary–adrenal (HPA) axis (pomca and nr3c1). The results indicated that TMBPA exposure adversely disrupted embryo hatching and larval development of zebrafish, accompanied by altering the expression of functional genes in larvae. These results provide further evidence for the potential environmental hazard posed by TMBPA.
{"title":"Toxic Effects of Tetramethyl Bisphenol A on Embryonic–Larval Development of Zebrafish (Danio rerio)","authors":"Eric Yin, Manwen Zeng, Haipeng Yan, Jiahao Gao, Zuchun Chen, Ning Zhang, Yusong Guo, Zhongduo Wang, Zhongdian Dong","doi":"10.3390/fishes10080407","DOIUrl":"https://doi.org/10.3390/fishes10080407","url":null,"abstract":"Tetramethyl bisphenol A (TMBPA), a novel alternative to Bisphenol A, is widely used as an industrial flame retardant and a raw material for tetramethyl polycarbonate plastics. With the increasing use of TMBPA, its aquatic ecological risks remain unclear. Therefore, this study investigated the developmental toxicity of TMBPA using zebrafish (Danio rerio) as a model, exposing embryos to 0.5, 5, 50, and 200 μg/L TMBPA for 120 h. The results showed that treatment with 5, 50, and 200 μg/L TMBPA decreased the hatching rate of zebrafish embryos at 48 h post-fertilization (hpf), while no significant difference was observed at 72 hpf. Meanwhile, TMBPA exposure at all concentrations showed no significant effect on the survival rate. Furthermore, a high concentration of TMBPA (200 μg/L) significantly reduced the total length and suppressed swimming ability in zebrafish larvae. In addition, gene expression analysis revealed impacts on antioxidant system (cat, gpx, mn-sod, keap1, ucp2, nrf2), hypothalamic–pituitary–thyroid (HPT) axis (ttr, ugt1ab, trβ), cardiac developmental (tbx2b, myl7, bmp4, notch1b, amhc), and the hypothalamic–pituitary–adrenal (HPA) axis (pomca and nr3c1). The results indicated that TMBPA exposure adversely disrupted embryo hatching and larval development of zebrafish, accompanied by altering the expression of functional genes in larvae. These results provide further evidence for the potential environmental hazard posed by TMBPA.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 8","pages":"407-407"},"PeriodicalIF":0.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/8/407/pdf?version=1755159502","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaoyu Chen, Jiaonan Zhang, Jiao‐Lin Zhang, Wenzheng Zou, Qingpi Yan
The health benefits associated with microbial species inhabiting aquatic animals have garnered increasing attention, as it is expected that the colonization and efficacy of native probiotic bacteria adapted to the internal environment of the target species will be more active than non-native bacteria. In this study, six isolates were obtained from the intestinal tract of largemouth bass. Three of these isolates demonstrated higher growth ability compared to the others and were further characterized using in vitro assays. Lactococcus lactis LBM15 was found to exhibit antibacterial activity against common pathogens affecting largemouth bass; the adhesion inhibition capabilities of the isolates were systematically evaluated through competitive, repulsive, and substitutive adhesion assays. The strain inhibited adhesion to all six tested pathogen strains, with competitive adhesion inhibition rates ranging from 42% to 54%, the highest of which was observed against V. anguillarum. Repulsive adhesion inhibition rates ranged from 27% to 55%, with the highest rate noted for Edwardsiella tarda. Additionally, substitutive adhesion inhibition rates were found to range from 48% to 76%, with the highest inhibition observed against Aeromonas hydrophila. Furthermore, LBM15 exhibited favorable antimicrobial susceptibility profiles, showing sensitivity to 21 antibiotics tested. Notably, safety assessment trials were performed exposing fish to LBM15 at a concentration of 1 × 109 CFU/mL by injection and at a concentration of 1 × 108 CFU/mL by feed administration. No clinical abnormalities, behavioral alterations, or mortality were documented in either exposure group, confirming the safety of LBM15 for application in aquaculture. The results suggested that LBM15 isolates from largemouth bass have potential for further investigation and possible application as probiotic candidates.
{"title":"Isolation, Characterization, and Assessment of Probiotic Lactococcus lactis from the Intestinal Tract of Largemouth Bass (Micropterus salmoides)","authors":"Xiaoyu Chen, Jiaonan Zhang, Jiao‐Lin Zhang, Wenzheng Zou, Qingpi Yan","doi":"10.3390/fishes10060291","DOIUrl":"https://doi.org/10.3390/fishes10060291","url":null,"abstract":"The health benefits associated with microbial species inhabiting aquatic animals have garnered increasing attention, as it is expected that the colonization and efficacy of native probiotic bacteria adapted to the internal environment of the target species will be more active than non-native bacteria. In this study, six isolates were obtained from the intestinal tract of largemouth bass. Three of these isolates demonstrated higher growth ability compared to the others and were further characterized using in vitro assays. Lactococcus lactis LBM15 was found to exhibit antibacterial activity against common pathogens affecting largemouth bass; the adhesion inhibition capabilities of the isolates were systematically evaluated through competitive, repulsive, and substitutive adhesion assays. The strain inhibited adhesion to all six tested pathogen strains, with competitive adhesion inhibition rates ranging from 42% to 54%, the highest of which was observed against V. anguillarum. Repulsive adhesion inhibition rates ranged from 27% to 55%, with the highest rate noted for Edwardsiella tarda. Additionally, substitutive adhesion inhibition rates were found to range from 48% to 76%, with the highest inhibition observed against Aeromonas hydrophila. Furthermore, LBM15 exhibited favorable antimicrobial susceptibility profiles, showing sensitivity to 21 antibiotics tested. Notably, safety assessment trials were performed exposing fish to LBM15 at a concentration of 1 × 109 CFU/mL by injection and at a concentration of 1 × 108 CFU/mL by feed administration. No clinical abnormalities, behavioral alterations, or mortality were documented in either exposure group, confirming the safety of LBM15 for application in aquaculture. The results suggested that LBM15 isolates from largemouth bass have potential for further investigation and possible application as probiotic candidates.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 6","pages":"291-291"},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/6/291/pdf?version=1750082160","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qingjun Shao, Yongming Ruan, Ru Liang, R. Jin, Jin Zhang, Lin Xie, Yihebali Chi, Jianyang Xia, Pingyang Zhu
Integrated rice–fish farming, crucial for sustainable agriculture, relies on the judicious use of pesticide. This study evaluates the toxicity of six common rice-field pesticides on Procypris merus (rice flower carp), a key species in these systems. We conducted acute and chronic toxicity tests, assessing survival, growth, oxidative stress (SOD, CAT, MDA, 8-OHdG), and neurotoxicity (AChE). Results revealed a spectrum of toxicity: abamectin and trifloxystrobin were highly toxic; pretilachlor was moderately so; and glufosinate-ammonium, triflumezopyrim, and thiazole zinc were low. Notably, triflumezopyrim induced significant oxidative stress and DNA damage, while all three low-toxicity pesticides inhibited AChE activity, indicating potential neurotoxicity. Despite these effects, all observed toxicities were reversible within 7–14 days. Considering that the tested concentrations exceeded typical field application rates, glufosinate-ammonium, triflumezopyrim, and thiazole zinc are deemed relatively safe for P. merus at recommended dosages. Our findings provide critical insights for optimizing pesticide selection in rice–fish farming, balancing pest control with ecological safety, thereby informing sustainable agricultural practices.
{"title":"Toxicity and Safety Assessment of Key Pesticides Used in Rice Fields on Rice Flower Carp (Procypris merus)","authors":"Qingjun Shao, Yongming Ruan, Ru Liang, R. Jin, Jin Zhang, Lin Xie, Yihebali Chi, Jianyang Xia, Pingyang Zhu","doi":"10.3390/fishes10060248","DOIUrl":"https://doi.org/10.3390/fishes10060248","url":null,"abstract":"Integrated rice–fish farming, crucial for sustainable agriculture, relies on the judicious use of pesticide. This study evaluates the toxicity of six common rice-field pesticides on Procypris merus (rice flower carp), a key species in these systems. We conducted acute and chronic toxicity tests, assessing survival, growth, oxidative stress (SOD, CAT, MDA, 8-OHdG), and neurotoxicity (AChE). Results revealed a spectrum of toxicity: abamectin and trifloxystrobin were highly toxic; pretilachlor was moderately so; and glufosinate-ammonium, triflumezopyrim, and thiazole zinc were low. Notably, triflumezopyrim induced significant oxidative stress and DNA damage, while all three low-toxicity pesticides inhibited AChE activity, indicating potential neurotoxicity. Despite these effects, all observed toxicities were reversible within 7–14 days. Considering that the tested concentrations exceeded typical field application rates, glufosinate-ammonium, triflumezopyrim, and thiazole zinc are deemed relatively safe for P. merus at recommended dosages. Our findings provide critical insights for optimizing pesticide selection in rice–fish farming, balancing pest control with ecological safety, thereby informing sustainable agricultural practices.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 6","pages":"248-248"},"PeriodicalIF":0.0,"publicationDate":"2025-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/6/248/pdf?version=1748152832","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanqing Wu, Ziying Zhu, Riying Zhong, Xilin Fang, Xiaocui Wang, Yuanyin Huang, Han Gong, Muting Yan
Microplastic pollution in the environment has greatly increased due to the widespread use of plastics. Antibiotics and microplastic are common contaminants, especially in aquaculture. Microplastics could act as antibiotic vectors that raise the potential of their ecotoxicological effects. In this work, we conducted several analyses of biomarker responses to examine the developmental toxicity and toxicological endpoints that polyethylene microplastics (PE-MPs) and tetracycline antibiotics (TC) induced in zebrafish (Danio rerio) embryos/larvae. The results suggested that TC-PE-MPs induced significant physiological perturbations, including attenuated spontaneous cardiac contractions, cardiotoxicity, a dose-dependent elevation in mortality, and a marked reduction in body length, accompanied by morphological alterations. The mechanistic analysis revealed that ROS accumulation triggered enzymatic activity changes, which further induced aberrant vascular development, robust inflammatory responses, and dysregulated gene expression. These findings demonstrate that PE coexistence potentiates TC’s toxicological effects, with combined exposure inducing developmental toxicity during critical organogenesis stages in zebrafish. Overall, the current research demonstrated the detrimental effects of TC-PE-MPs on early fish development, suggesting potential environmental risks.
{"title":"Microplastics Enhance the Toxic Effects of Tetracycline on the Early Development of Zebrafish in a Dose-Dependent Manner","authors":"Yanqing Wu, Ziying Zhu, Riying Zhong, Xilin Fang, Xiaocui Wang, Yuanyin Huang, Han Gong, Muting Yan","doi":"10.3390/fishes10040150","DOIUrl":"https://doi.org/10.3390/fishes10040150","url":null,"abstract":"Microplastic pollution in the environment has greatly increased due to the widespread use of plastics. Antibiotics and microplastic are common contaminants, especially in aquaculture. Microplastics could act as antibiotic vectors that raise the potential of their ecotoxicological effects. In this work, we conducted several analyses of biomarker responses to examine the developmental toxicity and toxicological endpoints that polyethylene microplastics (PE-MPs) and tetracycline antibiotics (TC) induced in zebrafish (Danio rerio) embryos/larvae. The results suggested that TC-PE-MPs induced significant physiological perturbations, including attenuated spontaneous cardiac contractions, cardiotoxicity, a dose-dependent elevation in mortality, and a marked reduction in body length, accompanied by morphological alterations. The mechanistic analysis revealed that ROS accumulation triggered enzymatic activity changes, which further induced aberrant vascular development, robust inflammatory responses, and dysregulated gene expression. These findings demonstrate that PE coexistence potentiates TC’s toxicological effects, with combined exposure inducing developmental toxicity during critical organogenesis stages in zebrafish. Overall, the current research demonstrated the detrimental effects of TC-PE-MPs on early fish development, suggesting potential environmental risks.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 4","pages":"150-150"},"PeriodicalIF":0.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/4/150/pdf?version=1743163676","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yijun Jia, Zhao Zhao, Leyang Chen, Yongqi Liu, Bin Zhu
A number of viral diseases have significantly impeded the growth of the aquaculture industry. Antiviral drugs represent an effective means of controlling infection. However, the efficacy of the entire therapeutic process is contingent upon the availability of an efficient delivery system. This study selected three common antiviral drugs and constructed corresponding drug delivery systems utilising single-walled carbon nanotubes (SWCNTs) as carriers. The reliability of carbon nanotubes as delivery carriers was evaluated by detecting the therapeutic effect on infectious splenic and renal necrosis virus (ISKNV). The findings demonstrated that SWCNTs can effectively enhance the absorption of the three drugs into the body, prolong their metabolic half-life, and improve the survival rate of fish infected with ISKNV. The Ribavirin-SWCNTs (RBV-SWCNTs) group exhibited the most pronounced protective effect, with a mortality rate of less than 25%. It was observed that SWCNTs facilitated the rapid transportation of ribavirin, with the drug content in the RBV-SWCNTs group being approximately double that of the free ribavirin group. Furthermore, this system markedly diminished the viral load, augmented enzyme activities, and elevated antiviral gene expression. This study indicated that carbon nanotubes are optimal carriers for antiviral drugs, which have considerable potential as a delivery vehicle for antiviral drugs to prevent viral infections in aquaculture.
{"title":"Carbon Nanotube-Based Drug Delivery System Increases Drug Content and Promotes Immune Response in Mandarin Fish","authors":"Yijun Jia, Zhao Zhao, Leyang Chen, Yongqi Liu, Bin Zhu","doi":"10.3390/fishes10030092","DOIUrl":"https://doi.org/10.3390/fishes10030092","url":null,"abstract":"A number of viral diseases have significantly impeded the growth of the aquaculture industry. Antiviral drugs represent an effective means of controlling infection. However, the efficacy of the entire therapeutic process is contingent upon the availability of an efficient delivery system. This study selected three common antiviral drugs and constructed corresponding drug delivery systems utilising single-walled carbon nanotubes (SWCNTs) as carriers. The reliability of carbon nanotubes as delivery carriers was evaluated by detecting the therapeutic effect on infectious splenic and renal necrosis virus (ISKNV). The findings demonstrated that SWCNTs can effectively enhance the absorption of the three drugs into the body, prolong their metabolic half-life, and improve the survival rate of fish infected with ISKNV. The Ribavirin-SWCNTs (RBV-SWCNTs) group exhibited the most pronounced protective effect, with a mortality rate of less than 25%. It was observed that SWCNTs facilitated the rapid transportation of ribavirin, with the drug content in the RBV-SWCNTs group being approximately double that of the free ribavirin group. Furthermore, this system markedly diminished the viral load, augmented enzyme activities, and elevated antiviral gene expression. This study indicated that carbon nanotubes are optimal carriers for antiviral drugs, which have considerable potential as a delivery vehicle for antiviral drugs to prevent viral infections in aquaculture.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 3","pages":"92-92"},"PeriodicalIF":0.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/3/92/pdf?version=1740149515","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The antifreeze and antioxidant capacities of tilapia (Oreochromis mossambicus) gelatin hydrolysates were investigated, after glycosylation with saccharides of varying molecular weights, to enhance their functional properties to widen its commercial application in frozen aquatic products. Glycosylation was conducted by mixing gelatin hydrolysates with ribose, glucose, maltose, and dextran (20 kDa) at a 1:1 mass ratio; the glycosylation products had a pH of 10 and were incubated at 80 °C for 1 h. The results showed that the glycosylation degree ranked as: ribose > glucose > maltose > dextran. The mass spectrometry analysis showed that 17, 32, and 5 glycosylation sites were identified for ribose, glucose, and maltose, respectively, suggesting a molecular weight-dependent effect. Spectroscopic analyses, including ultraviolet and infrared spectroscopy, revealed that the gelatin hydrolysate structure was expanded, with chromophores in hydrophilic environments; a blue shift in the amide A and II bands confirmed that the amino group was involved. Fluorescence spectroscopy showed conformational changes with a red shift at 303.4 nm and a reduction in intensity. Antifreeze activity, such as catalase freezing protection and shrimp surimi protein stability, and antioxidant activity, including radical scavenging and metal ion chelation, were significantly improved. Ribose exhibited the strongest effects, followed by maltose and glucose. These results demonstrate the potential of glycosylation to improve gelatin hydrolysates for functional applications.
{"title":"Glycosylation on the Antifreeze and Antioxidant Capacities of Tilapia Gelatin Hydrolysates","authors":"Ying Liu, Zongcai Tu, Qiuyu Lu, Shengnan Zhan, Ru Jia, Zhaohui Qiao, Huamao Wei, Tao Huang","doi":"10.3390/fishes10020065","DOIUrl":"https://doi.org/10.3390/fishes10020065","url":null,"abstract":"The antifreeze and antioxidant capacities of tilapia (Oreochromis mossambicus) gelatin hydrolysates were investigated, after glycosylation with saccharides of varying molecular weights, to enhance their functional properties to widen its commercial application in frozen aquatic products. Glycosylation was conducted by mixing gelatin hydrolysates with ribose, glucose, maltose, and dextran (20 kDa) at a 1:1 mass ratio; the glycosylation products had a pH of 10 and were incubated at 80 °C for 1 h. The results showed that the glycosylation degree ranked as: ribose > glucose > maltose > dextran. The mass spectrometry analysis showed that 17, 32, and 5 glycosylation sites were identified for ribose, glucose, and maltose, respectively, suggesting a molecular weight-dependent effect. Spectroscopic analyses, including ultraviolet and infrared spectroscopy, revealed that the gelatin hydrolysate structure was expanded, with chromophores in hydrophilic environments; a blue shift in the amide A and II bands confirmed that the amino group was involved. Fluorescence spectroscopy showed conformational changes with a red shift at 303.4 nm and a reduction in intensity. Antifreeze activity, such as catalase freezing protection and shrimp surimi protein stability, and antioxidant activity, including radical scavenging and metal ion chelation, were significantly improved. Ribose exhibited the strongest effects, followed by maltose and glucose. These results demonstrate the potential of glycosylation to improve gelatin hydrolysates for functional applications.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 2","pages":"65-65"},"PeriodicalIF":0.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/2/65/pdf?version=1740397702","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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