长江宜昌江段和东洞庭湖鲢、鳙饵料生物组成及季节性变化

为了研究鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)饵料生物组成及季节变化,分析了2016年7月-2017年3月在长江宜昌江段及东洞庭湖不同季度采集的84尾鲢和65尾鳙的肠道内含物。结果显示:鲢、鳙在长江宜昌江段摄食的饵料生物种类分别是55种和48种,在东洞庭湖分别是55种和43种。根据相对重要性指数(IRI),鲢、鳙的主要饵料生物均为枝角类。鲢、鳙食物组成呈现季节变化,鲢在长江宜昌江段春季、夏季、秋季和冬季的主要饵料生物分别是硅藻门、枝角类、枝角类和硅藻门,在东洞庭湖分别为枝角类、蓝藻门、枝角类和桡足类;鳙在长江宜昌江段春季、夏季、秋季和冬季的主要饵料分别是枝角类、枝角类、枝角类和硅藻门,在东洞庭湖分别为枝角类、枝角类、枝角类和桡足类。

Food composition and seasonal variation of Hypophthalmichthys molitrix and Aristichthys nobilis in Yichang section of the Yangtze River and East Dongting Lake

In order to study the composition and seasonal variations of food of H ypophthalmichthys molitrix and and A ristichthys nobilis,gut contents of 84 H.molitrix and 65 A.nobilis were collected in the Yichang section of the Yangtze River and the East Dongting Lake during July 2016 to March 2017.The results showed that 55 and 48 species of food ingested by H.molitrix and A.nobilis in Yichang section of the Yangtze River,respectively,55 and 43 in the East Dongting Lake,respectively.According to the relative importance index (IRI％),the dominant preys of H.molitrix and A.nobilis were Cladocera.And the food composition of H.molitrix and A.nobilis showed seasonal changes.The dominant preys of H.molitrix in spring,summer,autumn and winter were Bacillariophyta,Cladocera,Cladocera and Bacillariophyta respectively in the Yichang section of the Yangtze River,that of Cladocera,Cyanobacteria,Cladocera and Copepods in the East Dongting Lake.The dominant preys of A.nobilis in spring,summer,autumn and winter were Cladocera,Cladocera,Cladocera and Bacillariophyta respectively in the Yichang section of the Yangtze River,that of Cladocera,Cladocera,Cladocera and Copepods in the East Dongting Lake.