太湖敞水区鱼类种间关系现状

太湖敞水区鱼类群落组成，除人工放流的种类外，河湖洄游性鱼类已基本消失，以湖鲚、银鱼、虾类和小型鲤科鱼类种群占绝对优势。８种优势种种间协调系数显示，湖鲚、银鱼类，白虾，似鲚、九州稣箴等相互关系较为密切，其中太硝新银鱼和寡齿新银鱼之间除产卵期有先后外，时空分布和食饵对象基本一致。

PRESENT SITUATION OF INTERSPECIFIC RELATIONSHIP AMONG FISHES IN THE MAIN AREA OF TAIHU LAKE

The composition of fish communities showed that the migration fish species between river and lake was disappeared in the main area of Taihu Lake, except the stocked species. The main dominant species were lake anchovy (Coilia ectenes), Icefishes and smaller Cyprinids. The coefficient of association between 8 dominant species showed that lake anchovy, Icefishes, Palaemon modestus, Toxabramis swinhonis, and Neosalanx oligodontis have a similar temporal and spatial distributions, and similar prey, but they have different reproduction period. Generally, loss or reduction of a predator will lower the predation mortality of its prey, causing an increase of prey density and a concomitant increase in interspecific competition.