淀山湖光泽黄颡鱼食性研究

于2009年8月至2010年7月在上海市淀山湖采集光泽黄颡鱼胃含物样品,采用传统镜检法对其食性进行研究。结果表明:淀山湖光泽黄颡鱼全年均有摄食,且摄食强度存在显著的季节变化,其中饱满指数排序:秋 > 春 > 冬 > 夏,春季空腹率显著高于其他季节;共鉴定其饵料生物7大类(11小类),聚类分析表明,出现率(F%)、数量百分比(N%)和相对重要性指数(IRI%)在衡量食物对光泽黄颡鱼的重要性方面表现一致,重量百分比(W%)与前三者存在显著差异,综合以上4种指数显示,底栖甲壳类、多毛类和水生昆虫是光泽黄颡鱼的主要食物来源;选用W%对其食性进行时空比较,聚类分析显示其冬季食物组成与其他季节存在显著差异,而站点间差异不明显,均以底栖甲壳类为绝对食物来源;食物组成Shannon-Weiner多样性存在明显的空间差异,高低依次为S5 > S3 > S4 > S2 > S1 > S6,研究认为光泽黄颡鱼食性具有较强的地域性和可塑性。

Feeding habits of Pelteobagrus nitidus in Dianshan Lake

The samples of stomach content of Pelteobagrus nitidus were collected at 6 stations in Dianshan Lake from August 2009 to July 2010,and the food composition was investigated based on the analysis of stomach contents.Results showed that P.nitidus preyed around the year and its feeding intensity had significant seasonal variations with the highest index of fullness in autumn and the lowest in summer and with the highest rate of empty stomach in spring and the relatively lower in the other seasons.Seven broad diet categories(11 small diet categories)were identified.Cluster analysis showed that the occurrance rate(F%),numerical percentage(N%)and percent index of relative importance(IRI%)were consistent in measuring contribution of each food category to P.nitidus.There were significant differences between weight percentage(W%)and each of the above three indices in measuring the contribution.The polychaete,benthic crustacea,aquatic insect and zooplankton were the main food sources for P.nitidus in terms of the above-mentioned four indices.The numerical and gravimetric compositions both significantly differed between seasons,the former also conspicuously differed among stations,but the latter did not display marked spatial variation with benthic crustacea as the predominant food source for P.nitidus caught at each station.There were obvious spatial changes in diversity of food compositon with the lowest in winter(0.15),and the largest H' at Station 5(1.52)and the smallest at Station 6(0.72).P.nitidus displays high plasticity in food composition by comparison with the feeding spectrum of this species from the other lakes.