凤凰山天池断线麦穗鱼的摄食生态研究

为了解断线麦穗鱼(Pseudorasbora interrupta)在凤凰山天池的种群生物学特征,对其基础生物学特征进行了系统研究。2016年4月-2017年3月,于凤凰山天池共采集断线麦穗鱼281尾,利用胃(肠)含物分析法,分析其摄食强度、食物组成和摄食生态位。结果表明:断线麦穗鱼的摄食强度春季最低,夏、秋季较高,春秋季节差异明显。其饵料生物包括18个类群,以硅藻门占绝对优势(IRI=79.25%),其余依据IRI大小依次为绿藻门、水生昆虫、枝角类、甲藻门等。断线麦穗鱼的食物组成呈现季节变化,除全年均占绝对优势的硅藻外,次优势类群的四季差异明显。其中春季以水生昆虫和花粉较为常见;夏季以绿藻门和甲藻门较为常见;秋季以枝角类最多;冬季则为绿藻门占优。以特定饵料丰度和出现频率作图对摄食策略分析结果表明:断线麦穗鱼属于广食性鱼类,具有较为宽广的营养生态位。

Feeding ecological researches on Pseudorasbora interrupta in the top lake of Fenghuang Mountain

The basic biology of Pseudorasbora interrupta was researched systemically in this study to reveal the population characteristics of it in the top lake of Fenghuang Mountain.A total of 281 individuals were collected during April 2016 to March 2017.The feeding intensity, food composition and feeding ecology were studied based upon analysis of stomach(gut) contents.The main results showed that the feeding intensity of P.interrupta was lowest in spring, but higher in summer and autumn.The feeding intensity in spring showed significant difference with that in autumn.The food composition of P.interrupta contained 18 prey groups with Bacillariophyta dominating(IRI=79.25%), and other prey groups according to the amount of IRI were Chlorophyta, aquatic insects, Cladocera and Pyrrophyta etc.The dietary compositon of the prey consumed had obvious seasonal variations, with the exception that Bacillariophyta was dominant prey group across 4 sea-sons, subdominant prey groups varied significantly between four seasons.Aquatic insects and pollen were predominant groups in spring, Chlorophyta and Pyrrophyta in summer, Cladocerans in Autumn and Chlorophyta in winter.The analysis of feeding strategy based on the abundance of a prey taxon and the frequency of the occurrence showed that the P.interrupta was euryphagous fishes and had a wild niche width.