新疆额尔齐斯河银鲫食性分析

Feeding habits of Carassius auratus gibelio from Irtysh River in Xinjiang

以2013年4-10月在额尔齐斯河干流中国段下游采集的546尾银鲫(Carassius auratus gibelio)样本为研究对象,对银鲫的食物组成、摄食强度、摄食时空变化以及摄食策略等进行系统的分析和研究。统计结果显示,银鲫总体的空肠率为28.17%,且在繁殖季节前期(5月)的空肠率(54.7%)显著高于其他月份。以食物出现率比较,硅藻(100%)及摇蚊幼虫(86.67%)在银鲫食物组成中比较常见;植物碎屑质量百分比(61.52%)、优势度指数(62.36%)均最高,此外,改进的Costello图示法也表明植物碎屑为银鲫的主要食物。Kruskal-Wallis检验结果显示,额尔齐斯河银鲫不同季节的食物组成具有显著性差异,不同体长组间食物组成差异不显著。以上结果表明,额尔齐斯河银鲫为杂食性,且偏于植物食性。

A total of 546 Carassius auratus gibelio were collected from the lower reaches of the main stream of Irtysh River in China from April to October,2013.The food composition,feeding intensity and spatiotemporal variation,and feeding strategy of C.auratus gibelio were systematically analyzed and studied.The statistical results indicated that the overall jejunum rate of C.auratus gibelio was 28.17%,and the rates of jejunum before breeding season(May,54.7%)were significantly higher than those in other months.For food occurrence rate,Bacillariophyta(100%),and Chironomus larvae(86.67%)were common in the food composition of C.auratus gibelio.The weight percentage(61.52%),dominance index(62.36%),and Amundsen figure indicated that the plant debris were the most important prey of C.auratus gibelio.In addition,the food composition of C.auratus gibelio showed significant differences amomg different seasons(P<0.05),whereas showed no significant difference among different length groups(P>0.05).These results showed that C.auratus gibelio in Irtysh River is omnivorous and partial to phytophagy.