关键词: 底栖动物, 渔业增殖放流区, 桐庐段, 群落结构

Abstract: A seasonal investigation was conducted on the macrozoobenthos at 6 sections of enhancement and releasing zone in Tonglu section of Qiantang River from February to December in 2013. A total of 16 species were collected， which belonged to Mollusca， Annelida and Arthropoda， and Mollusca had the largest number of species. According to IRI value， Corbicula fluminea， Limnoperna lacustris and Nephthys sp. were the dominant species. All species were classified to 4 functional feeding groups: collectorfilterer， collectorgatherer， scraper and predator， of which the collectorfilterer was the predominant group. The mean annual density and biomass of the community were （39375±17372） m-2 and （29572±13197） g·m-2，respectively. There was no temporal significant difference in the macrozoobenthic density and biomass， but there was a significant variation in space. According to the community structure of macrozoobenthos， the sampling sections could be divided into 2 clusters， cluster A and B. In spring， summer and autumn， cluster A contained sectionⅠ， section Ⅵ， section Ⅴ and section Ⅳ， while cluster B contained section Ⅲ and section Ⅱ， which had a little difference in winter.

Key words:  macrozoobenthos, enhancement and releasing zone, Tonglu section, community structure