The effects of Fe2+ on the trimethylamine N-oxide (TMAO) demethylating activity of the Harpadon nehereus kidney extract were studied in this research.The activity of the kidney extract was presumably inhibited by ethy...The effects of Fe2+ on the trimethylamine N-oxide (TMAO) demethylating activity of the Harpadon nehereus kidney extract were studied in this research.The activity of the kidney extract was presumably inhibited by ethylene diamine tetra-acetic acid (EDTA),which indicates that the kidney extract contains an enzyme or enzyme system with metal cations as activator.Activity of the kidney extract was enhanced significantly when Fe2+ was added into the model system in vitro.As the concentration of Fe2+ increased,the decomposing rate of TMAO increased rapidly until TMAO decomposed completely.The activity of the kidney extract was also enhanced by reductant such as ascorbic acid.Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) was employed to determine the content of total iron in a number of fishery products.Significant positive correlation between the contents of total iron and endogenous formaldehyde (FA) was found,especially in marine products.展开更多
Based on two bottom trawl surveys conducted in autumn 2000 and 2001,a total of 1106 stomach samples of Bombay duck Harpadon nehereus between 23–278 mm fork length were collected and analyzed.The results show that Bom...Based on two bottom trawl surveys conducted in autumn 2000 and 2001,a total of 1106 stomach samples of Bombay duck Harpadon nehereus between 23–278 mm fork length were collected and analyzed.The results show that Bombay duck prey items consisted of 11 groups or 32 species,of which Apogon lineatus,Leptochela gracilis,Acetes chinensis,and Euphausia pacifi ca were the dominant prey species.Ontogenetic variations were found in feeding habits and feeding activity of Bombay duck.Feeding activity was highest in fi sh smaller than 50 mm,lowest in fi sh between 50 and 99 mm,and then increased with increasing size thereafter.As Bombay duck size increased,fi sh prey increased in importance,whereas euphausiids and decapods decreased in importance.Different trophic guilds were observed in feeding habits across the examined size range.Bombay duck smaller than 50 mm were zooplanktivores,mainly feeding on zooplankton and fi sh larva;those between 50 and 149 mm were generalist predators,mainly feeding on pelagic shrimps,demersal shrimps and fi shes;and those larger than 150 mm were piscivores,mainly feeding on fi shes.展开更多
Bombay duck(Harpadon nehereus)is an economically important species in the estuarine and coastal offshore waters of the Indo-West Pacific.This study aims to reveal the genome-wide genetic characteristics of five popula...Bombay duck(Harpadon nehereus)is an economically important species in the estuarine and coastal offshore waters of the Indo-West Pacific.This study aims to reveal the genome-wide genetic characteristics of five populations of H.nehereus from the coastal areas of China by using the genotyping-by-sequencing technique.After strict filtering,32088 high-quality single-nucleotide polymorphism markers were detected and analyzed.The average observed heterozygosity and expected heterozygosity ranged from 0.41651 to 0.56725 and from 0.30998 to 0.45531,respectively,indicating that heterozygosity excess occurred in H.nehereus populations.The nucleotide diversity ranged from 0.63664 to 0.74868,which was larger than those from other marine fishes.No obvious genetic structure was detected among H.nehereus populations,and the genetic variation originated within individuals.Extensive gene exchange caused by longshore currents in the reproductive season might be the primary reason for the weak genetic differentiation.Among various environmental factors,water temperature might be the key element affecting the genetic structure of H.nehereus.Due to the destruction and overfishing of spawning grounds,the fishery resources declined in recent years.This study could serve as a reference for the resource protection and rational utilization of H.nehereus.展开更多
Harpadon nehereus is a widespread economical fish found in the coastal seas of China and has important ecological value in the marine ecosystem.H_(o)wever,its germplasm resources have been seriously degraded due to na...Harpadon nehereus is a widespread economical fish found in the coastal seas of China and has important ecological value in the marine ecosystem.H_(o)wever,its germplasm resources have been seriously degraded due to natural factors and anthropogenic activities.In this study,high-throughput sequencing was applied to search for microsatellite loci in H.nehereus transcriptome to provide references for its resource conservation and utilization.Polymorphic loci were developed by non-denaturing polyacrylamide gel electrophoresis,and their cross-species amplified ability was detected in three related species.A total of 5652 microsatellites were identified from 16974320 unigenes.Among the primer pairs designed for 100 SSRs for PCR amplification,80%were successfully amplified,and 26 loci were polymorphic with a high number of alleles from 3 to 11 each.The expected(H_(e))and observed(H_(o))heterozygosities were 0.355–0.885 and 0.375–0.958,respectively.Most of the loci were highly polymorphic(polymorphism information content:0.316–0.852;mean:0.713),and these markers can be applied in the population genetic diversity research of H.nehereus.H_(o)wever,the transferability of these primers was low,probably because of the close relation of the collected species.In follow-up work,simple sequence repeats will be excavated with genome-based technologies,and related species will be gathered to address the present inadequacies.展开更多
为了评估“集成方法”能否改进物种分布模型(Species Distribution Models,SDMs)在海洋环境高度动态变化的河口区域的预测性能,本研究基于2013-2021年长江口海洋生物资源调查数据,使用8种基于不同算法的单一模型对长江口的优势物种之一...为了评估“集成方法”能否改进物种分布模型(Species Distribution Models,SDMs)在海洋环境高度动态变化的河口区域的预测性能,本研究基于2013-2021年长江口海洋生物资源调查数据,使用8种基于不同算法的单一模型对长江口的优势物种之一龙头鱼(Harpadon nehereus)构建了栖息地生境的集成模型(Ensemble Model,EM)。结果显示:(1)所有单一模型的预测性能均优于随机分布模型,而EM具有最高的预测准确性和稳健性(受试者工作特征曲线下面积(Area Under receiver operating character Curve,AUC)=0.875;真实技巧统计值(True skill statistic,TSS)=0.650;KAPPA系数=0.560;总体精度(Overall accuracy,OA)=0.867);(2)EM能最为准确地识别出龙头鱼的出现点和未出现点,也能清晰地区分出未采样区域适宜性水平的差异,并预测出不同模型共同的高适宜区域;(3)最后,EM能准确识别龙头鱼的关键环境需求并反映出多模型集中的变化趋势,其最适盐度、温度和化学需氧量的范围分别为2.754~30.300、28.278~30.934℃、4.605~8.080 mg/L。本研究可为长江口龙头鱼资源的可持续利用和栖息地保护工作提供更可靠的研究方法。展开更多
基金supported by the National Natural Science Foundation of China (No.30871949)
文摘The effects of Fe2+ on the trimethylamine N-oxide (TMAO) demethylating activity of the Harpadon nehereus kidney extract were studied in this research.The activity of the kidney extract was presumably inhibited by ethylene diamine tetra-acetic acid (EDTA),which indicates that the kidney extract contains an enzyme or enzyme system with metal cations as activator.Activity of the kidney extract was enhanced significantly when Fe2+ was added into the model system in vitro.As the concentration of Fe2+ increased,the decomposing rate of TMAO increased rapidly until TMAO decomposed completely.The activity of the kidney extract was also enhanced by reductant such as ascorbic acid.Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) was employed to determine the content of total iron in a number of fishery products.Significant positive correlation between the contents of total iron and endogenous formaldehyde (FA) was found,especially in marine products.
基金Supported by the National Natural Science Foundation of China(No.41076110)the National Basic Research Program of China(973 Program)(No.2011CB409805)
文摘Based on two bottom trawl surveys conducted in autumn 2000 and 2001,a total of 1106 stomach samples of Bombay duck Harpadon nehereus between 23–278 mm fork length were collected and analyzed.The results show that Bombay duck prey items consisted of 11 groups or 32 species,of which Apogon lineatus,Leptochela gracilis,Acetes chinensis,and Euphausia pacifi ca were the dominant prey species.Ontogenetic variations were found in feeding habits and feeding activity of Bombay duck.Feeding activity was highest in fi sh smaller than 50 mm,lowest in fi sh between 50 and 99 mm,and then increased with increasing size thereafter.As Bombay duck size increased,fi sh prey increased in importance,whereas euphausiids and decapods decreased in importance.Different trophic guilds were observed in feeding habits across the examined size range.Bombay duck smaller than 50 mm were zooplanktivores,mainly feeding on zooplankton and fi sh larva;those between 50 and 149 mm were generalist predators,mainly feeding on pelagic shrimps,demersal shrimps and fi shes;and those larger than 150 mm were piscivores,mainly feeding on fi shes.
基金supported by the Scientific Research Projects of the Zhejiang Bureau of Education(No.Y201942611)the Open Foundation from Marine Sciences in the First-Class Subjects of Zhejiang Province.
文摘Bombay duck(Harpadon nehereus)is an economically important species in the estuarine and coastal offshore waters of the Indo-West Pacific.This study aims to reveal the genome-wide genetic characteristics of five populations of H.nehereus from the coastal areas of China by using the genotyping-by-sequencing technique.After strict filtering,32088 high-quality single-nucleotide polymorphism markers were detected and analyzed.The average observed heterozygosity and expected heterozygosity ranged from 0.41651 to 0.56725 and from 0.30998 to 0.45531,respectively,indicating that heterozygosity excess occurred in H.nehereus populations.The nucleotide diversity ranged from 0.63664 to 0.74868,which was larger than those from other marine fishes.No obvious genetic structure was detected among H.nehereus populations,and the genetic variation originated within individuals.Extensive gene exchange caused by longshore currents in the reproductive season might be the primary reason for the weak genetic differentiation.Among various environmental factors,water temperature might be the key element affecting the genetic structure of H.nehereus.Due to the destruction and overfishing of spawning grounds,the fishery resources declined in recent years.This study could serve as a reference for the resource protection and rational utilization of H.nehereus.
基金supported by the Scientific Research Projects of Department of Education of Zhejiang Province(No.Y201942611)the Science and Technology Innovation Project of College Students in Zhejiang Province(No.2021R411008)the Open Foundation from Marine Sciences in the First-Class Subjects of Zhejiang Province.
文摘Harpadon nehereus is a widespread economical fish found in the coastal seas of China and has important ecological value in the marine ecosystem.H_(o)wever,its germplasm resources have been seriously degraded due to natural factors and anthropogenic activities.In this study,high-throughput sequencing was applied to search for microsatellite loci in H.nehereus transcriptome to provide references for its resource conservation and utilization.Polymorphic loci were developed by non-denaturing polyacrylamide gel electrophoresis,and their cross-species amplified ability was detected in three related species.A total of 5652 microsatellites were identified from 16974320 unigenes.Among the primer pairs designed for 100 SSRs for PCR amplification,80%were successfully amplified,and 26 loci were polymorphic with a high number of alleles from 3 to 11 each.The expected(H_(e))and observed(H_(o))heterozygosities were 0.355–0.885 and 0.375–0.958,respectively.Most of the loci were highly polymorphic(polymorphism information content:0.316–0.852;mean:0.713),and these markers can be applied in the population genetic diversity research of H.nehereus.H_(o)wever,the transferability of these primers was low,probably because of the close relation of the collected species.In follow-up work,simple sequence repeats will be excavated with genome-based technologies,and related species will be gathered to address the present inadequacies.
文摘为了评估“集成方法”能否改进物种分布模型(Species Distribution Models,SDMs)在海洋环境高度动态变化的河口区域的预测性能,本研究基于2013-2021年长江口海洋生物资源调查数据,使用8种基于不同算法的单一模型对长江口的优势物种之一龙头鱼(Harpadon nehereus)构建了栖息地生境的集成模型(Ensemble Model,EM)。结果显示:(1)所有单一模型的预测性能均优于随机分布模型,而EM具有最高的预测准确性和稳健性(受试者工作特征曲线下面积(Area Under receiver operating character Curve,AUC)=0.875;真实技巧统计值(True skill statistic,TSS)=0.650;KAPPA系数=0.560;总体精度(Overall accuracy,OA)=0.867);(2)EM能最为准确地识别出龙头鱼的出现点和未出现点,也能清晰地区分出未采样区域适宜性水平的差异,并预测出不同模型共同的高适宜区域;(3)最后,EM能准确识别龙头鱼的关键环境需求并反映出多模型集中的变化趋势,其最适盐度、温度和化学需氧量的范围分别为2.754~30.300、28.278~30.934℃、4.605~8.080 mg/L。本研究可为长江口龙头鱼资源的可持续利用和栖息地保护工作提供更可靠的研究方法。
