博斯腾湖哲水蚤种群消失与池沼公鱼的关系

哲水蚤目(Calanoida)是水体中的浮游生物主要种类组成之一,也是各种幼鱼和食浮游生物鱼类良好的天然饵料,其种类组成及数量变动往往直接制约经济鱼类的丰度.哲水蚤摄食浮游藻类、细菌及腐屑,对藻类的生长、防治水体富营养化和水体自净起到重要作用,在生态系统物质循环和能量流动中起着至关重要的作用.采用<内陆水域渔业自然资源调查手册>有关方法,1984～2006年,以新疆博斯腾湖哲水蚤和池沼公鱼(Hypomesus olidus)为研究对象,通过对哲水蚤种类、数量和生物量的变化及对池沼公鱼生物学食性、种群数量进行长期观察,结果表明,在各种食物都比较丰盛时,公鱼摄食哲水蚤的出现率最高(41.6%),池沼公鱼种群数量的大量增加导致了哲水蚤逐渐减少乃至消失.

The Relationship between the Disappearence of Calanoida Population and the Introduction of hypomesus olidus in Bosten Lake

A long-term survey was conducted to investigate the species composition and population fluctuation of Calanoida, food composition and population fluctuation of Hypomesus olidus in Bosten Lake from 1984 to 2006, and the relationship between those of Calanoida and H. olidus was analyzed. The result showed that the occurrence rate of. Calanoida in the diets of H. olidus was high when there was abundant variety of food item. Rapid increase of H. olidus population resulted in the intensification of predation stress on Calanoida, caused the reduction of Calanoida both in species number and population size, and finally, the disappearance of Calanoida in Bosten Lake.