嘉陵江干流鱼类群落生态结构分析

鱼类群落生态结构是群落生态学研究的一个热点问题。通过野外调查和资料分析发现，嘉陵江干流分布鱼类有156种，隶属于7目18科85属。依据所摄取食物类型的不同，这些鱼类可以划分为浮游动物食性、浮游植物食性、着生藻类食性、水生植物食性、水生昆虫食性、软体动物食性、肉食性和杂食性等8种食性类型。使用相似性指数和相似性分析方法，对嘉陵江上、中和下游的鱼类组成及群落生态结构组成分析发现：（1）从上游到下游，鱼类物种逐渐增加；（2）整个嘉陵江干流中，水生昆虫食性的鱼类占3141%，肉食性占1923%，着生藻类食性占1859%，软体动物食性的占1154%，浮游动物食性占1026%，杂食性占641%，水生植物食性占192%，浮游植物食性占064%；（3）从上游到下游，肉食性鱼类所占比例逐渐增加，以水生昆虫和着生藻类为食的鱼类所占比例则逐渐减少，相似性分析表明，嘉陵江各江段鱼类群落生态结构组成的差异不显著。嘉陵江干流鱼类群落生态结构的组成和变化与水生态系统结构和功能的变化密切相关

STUDIES ON ECOLOGICAL STRUCTURE OF FISH COMMUNITY IN JIALING RIVER

Ecological structure of fish community is a hot issue in community ecology.According to historical records and specimens preserved in the collection museum of College of Life Science,China West Normal University,there are a total of 156 fish species in Jialing River,belonging to 85 genera,18 families and 7 orders.Based on their feeding mode,these fishes can be categorized into eight types,zooplanktivores,phytoplanktivores,phytobenthivores,herbivores,insectivores,zoobenthivores,piscivores,and ominviores as well.The results of the relative index analysis and the analysis of similarities of the ecological structure of fish community along the whole Jialing River show that the number of fish species increase a litter from upstream to downstream.For the ecological structure of fish community,the insectivores account about 31.41% of the total species,with piscivores,phytobenthivores,zoobenthivores,zooplanktivores,ominviores,herbivores and phytoplanktivores following,which are 19.23%,18.59%,11.54%,10.26%,6.41%,1.92% and 0.64% respectively.From upstream to downstream,the proportions of piscivores are increasing,and these of the insectivores and phytobenthivores are decreasing,while the analysis of similarities suggests that there is no significant difference in ecological structure of fish community in Jialing River.The variation of ecological structure of fish community along the Jialing River is closely related to the change of the structure and function of the aquatic ecosystem.