太湖不同湖区轮虫群落结构季节变化的比较研究

2006年7月～2007年6月对太湖不同湖区(河口区、梅梁湾、太湖湖心区和贡湖湾)轮虫的季节变化进行了比较研究.整个研究期间,河口区、梅梁湾、太湖湖心区和贡湖湾轮虫种类数分别为23、15、14和21;河口区轮虫的年平均密度最高,为475个·L-1,梅梁湾最低,为164个·L-1,太湖湖心区为189个·L1-,贡湖湾为338个·L-1.4个湖区优势种不同,河口区轮虫优势种为萼花臂尾轮虫(B.cdyciflorus),梅梁湾为角突臂尾轮虫(B.angularis),太湖湖心区和贡湖湾优势种都是针簇多肢轮虫(P.trigla).食物的不同以及大型浮游甲壳动物的抑制作用,可能是太湖4个湖区轮虫群落结构不同的重要原因.相关分析表明,轮虫数量与枝角类数量、枝角类生物量和桡足类生物量极显著负相关;轮虫数量与透明度显著正相关.结果表明,太湖4个不同湖区轮虫群落结构不同.

Comparative Study on Seasonal Variations of Community Structure of Rotifer in Different Lake Areas in Lake Taihu

A comparative study on seasonal variations of rotifer in different lake areas, including the riverine zone, Meiliang Bay, the central open water area and Gonghu Bay in Lake Taihu, was conducted from Jul. 2006 to Jun. 2007.Twenty-three rotifer species were identified in the riverine zone, 15 in Meiliang Bay, 14 in the central open water area and 21 in Gonghu Bay. The annual average density of rotifer was 475 individuals·L^-1 in the riverine zone, 164 individuals·L^-1 in Meiliang Bay, 189 individuals·L^-1 in the central open water area and 338 individuals·L^-1 in Gonghu Bay. The dominant species were different in the four different Lake areas.In the riverine zone, B.calyciflorus was the dominant species. In Meiliang Bay, B.angularis was the dominant species.However, in Gonghu Bay and the central open water area, P.trigla was the dominant species. The foods and suppression by large crustaceans are both important factors in determining the structure of rotifer community among the four differential lake areas in Lake Taihu. There were significant negatively correlations between the abundance of rotifer and the abundance of cladoceran, the biomass of cladoceran and copepod. The number of rotifers was positively related to Secchi transparency. Results indicate that the structure of rotifer community differs from the four differential lake areas in lake Taihu.