金沙江上游赠曲的鱼类与裸腹叶须鱼的食性

2013年5月和9月对金沙江上游支流赠曲的鱼类资源和裸腹叶须鱼的食性特征进行了调查研究。结果表明,赠曲现有鱼类10种,隶属2目3科5属,其中鲤科鱼类7种,占70%;鮡科2种,占20%;鳅科1种,占10%。赠曲裸腹叶须鱼的食物组成包括53种(属)的浮游藻类、原生动物和节肢动物等。硅藻门是出现率百分比、相对重要性指数和数量百分比最高的饵料生物;水生昆虫是质量百分比最大的饵料生物。裸腹叶须鱼的摄食强度存在较明显的季节差异,雨季末期的摄食强度较低。食物中植物性饵料相对重要性随着裸腹叶须鱼体长的增长而增加。综合而言,赠曲的鱼类组成较为简单,鲤科鱼类是优势类群;裸腹叶须鱼属杂食性鱼类,且摄食强度存在季节性差异。为保护赠曲鱼类,建议在赠曲梯级水力开发过程中做好鱼类栖息地保护或再造等生态补偿措施。

FISH RESOURCES AND FEEDING HABITS OF PTYCHOBARBUS KAZNAKOVI IN THE ZENGQU RIVER,A TRIBUTARY OF THE UPPER JINSHA RIVER

Studies on the status of fish resources and feeding habits of Ptychobarbus kaznakovi of the Zengqu River, in the upper Jinsha River, were conducted in May and September, 2013. A total of 10 fish species belonging to 2 orders and 3 families and 5 genera were found in the Zengqu River. The Cyprinidae included 7 species accounting for 70% of species; Sisoridae included two species accounting for 20% of species; Cobitidae included one species accounting for 10% of species. The diet of P. kaznakovi consisted of 53 genera or species, which included phytoplankton, protozoa, arthropod, etc. Bacillariophyta had the highest occurrence rate percentage, index of relative importance and quantity percentage among the all prey species. Aquatic insects had the highest mass percent among the all prey species. There was an obvious seasonal difference in feeding intensity of P. kaznakovi, which had relative lower feeding intensity in the end of the rainy season. Index of relative importance of plant in the diet increased with the growth of body length of P. kaznakovi. The present study indicates that the fish composition of the Zengqu River was simple, and Cyprinidae fishes were the dominant fish species. P. kaznakovi is omnivorous fish with seasonal variation. It is suggested that ecological compensation measures such as fish inhabitant conservation or reconstruction should be done during the hydropower cascade development to protect the fish in the Zengqu River.