中文摘要：

2006年4月至2007年3月，对清江流域上游一二级支流——胡家溪的大型底栖动物群落结构进行了调查研究，并利用生物指数对河水水质进行了系统评价．结果表明，共采集到大型底栖动物87种，其中环节动物3种，软甲动物3种，水生昆虫76种，软体动物5种．群落表现出明显的时空特点，6月份的物种最多，12月份的物种最少，S5的物种最多，S1的物种最少；各微生境中共有种占据优势，物种相似性均大于75％；功能摄食群则以收集者占优，共计达51种．群落密度在4月份达到最大，为3293ind．／m^2；而生物量则在12月份达到最大，为163g／m^2．采用Shannon多样性指数、生物指数和科级水平生物指数对胡家溪水质评价的结果是河水水质比较清洁．

英文摘要：

Community structure of macrozoobenthos and the bioassessment on water quality in a second order river-Hujiaxi Stream of Qingjiang River basin were investigated from April 2006 to March 2007. The results showed that, among collected altogether 87 species of macroinvertebrates, there were 3 species of Annelida, 3 species of Mollusca, 76 species of aquatic insects, and 5 species of Malacostraca. The community structure exhibited obvious spatial and temporal variations. The species number reached its peak in June, and descended to the lowest in December. There was the largest species number in Site 5, and more species macroinvertebrates were presented in June than those in other months. Over 75% of the collected species could inhabit in all six types of microhabitats. The density of the community reached its peak in April at 3293 each/m^2, while biomass attained its peak in December at 163 g/m^2. The water quality was bio-assessed with Shannon-Weaner diversity, Biotic Index （BI） and Family Biotic Index （FBI）, and results showed that the river water was fairly clean during the sampling period. Considering the coincidence with physical-chemical parameters, BI and FBI bio-assessment methods were much fit to apply in rivers of China.