长江口轮虫生物多样性特征分析

长江口径流在南北支分布不均导致北支盐度高于南支,因此南北支之间生物群落存在一定差异。2010年在长江口分支前的江段和南北支设置5个断面,开展轮虫生态研究。分支前的太海汽渡断面处共采集到轮虫9种,隶属6科8属,其中优势种为没尾无柄轮虫、暗小异尾轮虫、萼花臂尾轮虫等;长江口南支2个断面共采集轮虫20种,隶属于6科12属,南支优势种为暗小异尾轮虫、盘状鞍甲轮虫和蹄形腔轮虫;长江口北支2个断面共采集轮虫11种,隶属于7科10属,北支优势种为舞跃无柄轮虫、没尾无柄轮虫和盘状鞍甲轮虫。南支轮虫种类、密度、多样性都高于北支,南北支的轮虫群落相似度较低。轮虫与水域环境因子相关性分析显示,盐度的差别影响了轮虫种类组成、密度和空间分布。

Diversity characteristics of rotifer community at the Yangtze River estuary

The distribution of runoff at the Yangtze River estuary is uneven,the runoff in the south branch is more than in the north,and the north salinity is greater than the south,so there is some difference in biological community between the south and north branches. We collected rotifers from five cross-sections in the south and north branches and investigated the rotifer biology. A total of 9 species were identified at the Taihaiqidu cross-section,belonging to 8 genera,6 families,and the dominant species were Ascomorpha ecaudis,Trichocerca pusilla,Brachionus calyciflorus,et al. 20 rotifer species were identified in the south branch,belonging to 12 genera,6 families,and the dominant species of the south branch T. pusilla,L. patella,Lecane ungulata; 11 rotifer species were identified in the south branch,belonging to 10 genera,7 families,and the dominant species of the north branches were A. saltans,A. ecaudis,L. patella. We compared the component and structure of rotifer in the south and the north branches,and found that the species,density,diversity of the south was higher than those of the north,similarity of rotifers in the south and north branches was low. The different water environment of the two branches caused the difference of rotifer community structure,correlation between rotifers and water environment factors was analyzed by relativity analysis among which salinity was the important factor,and difference of salinity determined the difference in species,density,and spatial-distribution of rotifer.