太湖主要鱼类食物组成与资源利用状况评价的研究.doc

太湖主要鱼类食物组成的研究 刘恩生 安徽农业大学动物科技学院，安徽合肥 230036 摘要：根据2004年9～12月和2005年4月的调查，研究了太湖8种鱼的食物组成。结果表明：优势种鲚鱼主要摄食枝角类、占食物个数比例89.77±13.69%；太湖新银鱼主要摄食桡足类、占个数比例70.11±10.57%；鲢、鳙主要摄食微囊藻、占食物体积比例90%以上；鲤食物中水生植物约占体积比例70%；鲫主要摄食微囊藻、占体积比例93.99±3.34%；翘嘴红鲌、蒙古红鲌主要摄食鲚鱼和小型鱼类。分析认为，随着太湖富营养化程度不断加重，以蓝藻为主的浮游植物食性鱼产力在快速增加，但实际渔获量以浮游动物食性鱼类为主。如2003年浮游植物食性鱼产力为10234 t、占总鱼产力37.0%。而2004年实际渔获量中浮游动物食性鱼类占80%～90%，浮游植物食性鱼类渔获量仅3637.7t、占10.9%。因此，太湖现有鱼类群落组成和实际饵料构成是不吻合的。不仅如此，浮游动物食性鱼类数量的快速增加对浮游动物形成了巨大牧食压力，这更利于藻类繁殖。太湖鲫鱼几乎完全以微囊藻为食物，可能对蓝藻暴发有抑制作用，应重新评价其对环境的影响。 关键词：太湖；主要鱼类；食物组成；富营养化；微囊藻 中图分类号： 文献标记码：A A study on diet composition of dominant fishes in Lake Taihu LIU En-sheng (Anhui Agricultural University, Hefei 230036, China) Abstract: Based on the investigations during September and December in 2004 and April in 2005, the diet composition of eight species of fishes in Lake Taihu was studied. The results were as follows: Coilia ectenes taihuensis Yen et Lin mainly fed on Cladocera accounting for 89.77?3.69% of individual composition in its food; Neosalanx tangkahkeii taihuensis Chen mainly fed on Copepoda accounting for 70.11±10.57% of individual composition in its food; Microcystis occupied over 90% of volume composition of the food of Hypophthalmichthys molitrix (Cuvier et Valenciennes) and Aristichthys nobilos (Richardson); Water plant occupied over 70% of volume composition of the food of Cyprinus carpio Linnaeus; Microcystis accounted for 93.99±3.34% of volume composition of the food of Carassius auratus Linnaeus; Erythroculter ilishaeformis Bleeker and Erythroculte rmongolian Basilewsky mainly fed on Coilia ectenes taihuensis Yen et Lin and small-sized fishes. The conclusion was that the potential productivity of phytoplanktivores quickly increased, but the dominant fishes in fish catches were zooplanktivores fishes in Lake Taihu. For example, the potential productivity of phytoplanktivores was 10234 t accounting for 37.0% of the total potential fish productivity in 2003. But phytoplanktivor