东海单角革鲀成鱼群体秋季摄食习性的初步分析

Preliminary Study on the Feeding Habits of Aluterus monoceros Adult Group in East China in Autumn

分析了2008年秋季(11月)东海单角革鲀的食物组成及摄食的体长变化,并用聚类分析和卡方检验等方法进行相关研究。结果表明:单角革鲀摄食的饵料种类有26余种,小型鱼类为其主要食物类群,浮游甲壳类为其次要食物类群。优势饵料种类有七星底灯鱼、细条天竺鲷、不可辨认虾(Unidentified natantia)和细螯虾。统计分析检验表明,单角革鲀的平均胃饱满系数无显著的体长变化(P>0.05),空胃率有显著的体长变化(P<0.01)。聚类分析的结果表明,单角革鲀体长150 mm和300 mm分别是其摄食取向的拐点,体长小于150 mm的以磷虾为主,大于150 mm而小于300 mm则以小型鱼类和磷虾类为主,体长大于300 mm的则仅以小型鱼类为主,摄食范围也随体长的增加而增加。

Based upon stomachs collected from the East China Sea during autumn in 2008, feeding habit of Aluterus monoceros was investigated. The diet composition and ontogenetic variation in the feeding of A. monoceros were examined by applying the cluster analysis and chi-squared test. The results show that more than 26 prey species were ingested by A. monoceros. Small scale marine fish was the dominant prey group, followed by planktonic crustaceans. At the species level, Benthosema pterotum, Apogonichthys lineatus, u- nidentified natantia and Leptochela gracilis dominated the diet of A. monoceros, with the former being the most important prey species. Statistical analysis showed that the percentage of empty stomachs index,which wereanalyzed by applying the chi-square test and Kruskal-Wallis test, varied significantly among size classes. But mean stomach fullness index did not. The results of cluster analysis showed that there was an abrupt change in diet composition at about 150 mm and 300 mm of body length （BL）. Euphausiacea were the dominant prey groups of fish smaller than 150 mm BL,the small-size marine fish and Euphausiacea were the dominant prey groups of fish greater than 150 mm and smaller than 300 mm BL, whereas small-size marine fish was only the dominant prey for fish greater than 300 mm BL. The feeding range also increased with body length increas- ment.