流溪河保护区鱼类群落结构及其时空变动

为了解流溪河光倒刺鲃国家级水产种质资源保护区鱼类群落结构,分析不同河段、不同季节鱼类群落多样性的变化,于2017年12月-2018年10月对保护区上、中、下游的鱼类开展了每个季度一次的调查。调查结果显示,共采集鱼类57种,隶属于5目14科50属,其中鲤形目43种、鲈形目6种、鲇形目5种,合鳃鱼目2种,鳉形目1种;计算57种鱼类的相对重要性指数,结果显示,尼罗罗非鱼、越南■及鲤鱼为2017-2018年度优势种;Shannon-Wiener多样性指数、Margalef丰富度指数和Pielou均匀度指数计算结果显示,下游鱼类群落的多样性及均匀度最高,夏季鱼类群落的多样性、丰富度及均匀度最高;各监测点之间的种类相似性系数显示,保护区上中游、上下游之间鱼类种类组成为中等不相似,中下游种类组成为中等相似,春夏、春冬、夏冬及夏秋季节鱼类种类组成为中等不相似,春秋、秋冬季节为中等相似;ABC分析结果显示,春、夏及冬季鱼类群落处于稳定状态,秋季处于中度干扰状态。

Community Structure and Spatio-temporal Variation of Fish in Liuxi River Reserve

Fish were sampled at 3 monitoring sites in Spinibarbus hollandi National Aquatic Germplasm Reserve in Liuxi River in winter(December 2017), spring(April 2018), summer(June 2018) and autumn(October 2018) by the combination of gill nets, trap cages and electric fishing in order to understand the structure of fish community in Liuxi River National Aquatic Germplasm Resources Reserve and the changes in fish community diversity in different river sections and seasons. During this survey, 57 species of fish were collected, belonging to 5 orders, 14 families and 50 genera, including 43 species in Cypriniformes, 6 species in Perciformes, 5 species in Siluriformes, 2 species in Synbgranchiformes and 1 species in Cyprinodontiformes. The relative importance index(IRI) showed that Nile tilapia Oreochromis niloticus, Acheilognathus tonkinensis and common carp Cyprinus carpio were the annual dominant species from 2017 to 2018. The Shannon-Wiener(H′), richness(D) and evenness(J′) revealed that there were the maximal species diversity and uniformity of fish communities in downstream, and that there were higher species diversity, richness, and uniformity of fish communities in summer than those in the other seasons. The Jaccard′s similarity index between the monitoring sites showed that the composition of fish species in the upstream and midstream, and upstream and downstream were medium dissimilar and the midstream and downstream were moderately similar. The fish species composition was found to be medium dissimilar in spring and summer, spring and winter, summer and winter, summer and autumn and moderately similar in spring and autumn, autumn and winter. ABC curve analysis revealed that the fish community in spring, summer and winter was in a stable state, and in a state of moderate disturbance in the autumn.