【摘要】 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，种群数量以湖鲚、银鱼、虾类和小型鲤科鱼类占绝对优势。群落物种多样性指数值表明属温带水域范围，具有明显的年、月变化。群落内群体结构中，生命周期长的种类，小型化、低龄化和早熟化现象明显，而1年周期的种类中太湖新银鱼的产卵期已有明显延长的趋势。6种优势种种间关系显示，太湖新银鱼和寡齿新银鱼之间，除产卵期有先后外，时空分布几呈重叠状，饵料组成也基本一致。敞水区鱼类群落属全局稳定类型。实施人工放流后，原区系组成中的外源种数量，从近十年产量分析，尚没有因种类丰度交替而瓦解群落结构的情况发生。1994年的超强度捕捞已使银鱼生物量明显下降，远离了平衡点，故当前应优先通过内源种增殖恢复其资源量，到达平衡点后再考虑外原种的移入。更多还原

【Abstract】 The stock biomass in the open water zone of Taihu lake are dominated by lake anchovy (Coilta ectenes), icefishes, and smaller cyprinids. The stock of structures in community showed a characteristic of small-sized individual, early ripening at low age for longevous species.However the spawning time of Neosalanx taihuensis (a shortlif fish) has been tending to prolong. The fish community of open water zons is belong to a global stability type. Based on the analysis of the past decade catehes in Taihu lake, the stocked exotic species have not disintegration community structure, but the abundace of icefishes is greatly decreased and it’s for away from the balance point of stock, because of overfishing in 1994. Therefore the authors suggnsted not to transplant exoticpeies until to the stock returns to mormal condrtron.更多还原