珠江水系北江鱼类群落多样性及其演替

摘要：2014-2016年对珠江水系北江5个采样点进行逐月鱼类多样性调查，共采集鱼类86种，隶属于11目25科64属。其中鲤形目49种，鲈形目14种，鲇形目10种，鲱形目4种。其余脂鲤目、颌针鱼目、鳉形目、合鳃鱼目、鲑形目、鲻形目以及鳗鲡目种数均少于5种。北江鱼类群落以定居性、杂食性种类为主。与历史资料相比，鱼类种类减少，洄游性、半洄游性鱼类所占比例下降，定居性、杂食性鱼类所占百分比上升，鱼类群落组成偏向小型化、低龄化。群落多样性分析表明，相同生境类型河段的鱼类物种相似性较高，上游鱼类多样性高于下游。河道水利、过度捕捞和生境退化是北江鱼类群落演替的主要原因。

The fish community diversity and succession in the Beijiang River of the Pearl River system

Abstract: we conducted a montly field-survey of fish diversity in Beijing River from 2014 to 2016.During this survey, we captured 86 species of fishes, belonging to 11 orders, 25 families and 64 genera. Among these fishes, there were 49 species of Cypriniformes, 14 species of Perciformes , 10 species of Siluriformes, 4 species of Clupeiformes.The rest Characiformes, Beloniformes, Cyprinodontiformes, Synbranc, Salmoniformes ,Mugiliformes and Anguilliformesspecies were less than 5.The ecological types of the fish community in Beijiang River were dominated by Sedentary species and Omnivore species.Compared with the historic data,fish species to reduce,the proportion of migratory and half-migratory species decreased,the proportion of sedentary and omnivore species increased,fish community composition towards miniaturization, younger age. According to the analysis of the community diversity,fish species in similar habitats had higher similarity, the diversity of species in the upper stream is higher than that in the downstream.River water conservancy, overfishing and habitat degradation are the main cause of Beijiang River fish community succession.