白龟山水库银鱼移植试验

TRANSPLANTING OF NEOSALANX TAIHUENSIS CHEN IN BAIGUISHAN RESERVIOR

1987年一次性向白龟山水库投放太湖新银鱼有效受精卵21×10~4粒,后形成强大种群生产力,1991～1993年累计生产银鱼190t,创经济效益500余万人民币。太湖新银鱼具有生命周期不长、食物链较短、适应环境能力较强、容易捕捞等优点,是“填补”移植驯化的理想对象。白龟山水库生态系中鱼类区系组成不够饱和,存有空闲小生境,饵料竞争比较缓和,敌害压力较小,是移植驯化银鱼的适宜水体。白龟山水库银鱼食性组成中以桡足类和枝角类为主;分布遍及全库,尤以上、中游水草区为最多。1991年全库银鱼相对资源蕴藏量为108920kg,即1.56×10^(?)尾。1991年约有29.5％的浮游动物被银鱼利用转化成为银鱼产品,生物学效益较高。综合考虑银鱼的繁殖和生长,在现有捕捞强度下,捕捞生产宜安排在11月～翌年2月为宜。

Baiguishan Reservoir is a multi-purpose one in the Huanhe River systems. A stocking of 210000 fertilized eggs of Neosalanx taibuensis Chen was reached in this reservoir in 1987. Ice fish catch totaled 190t in 1991~1993, equalling an economic value of over 5×10~6yuan. Neosalanx taihuensis Chen, characterized by short life cycle, short food chains, high tolerance of environmental conditions, easy catch etc. , can be successfully domesticated as supplementation. On the ecosystems of Baiguishan reservoir, niches are not fully occupied with less competition of food, ice fish is suitable for domestication in this kind of water body. The reproductive biological characteristics of ice fish are quite similar in this reservoir to those in Taihu Lake. The food compositions are mainly copepoda and cladocera. The ice fish widely distributed in the reservoir and a heavy population is found in the densely-grown water grasses in the upper and middle reaches. In the light of estimation in 1991, the potential stock of ice fish in the whole reservoir was expected to be 108920 kg at 156 million in numbers. The biological benefits are extremely high from 1987 to 1991. About 29. 5% of the biomass of zooplankton was consumed by the ice fish stocked.