夏、秋季浙江南部近海带鱼摄食习性分析

Feeding Habits of Hairtail Trichiurus japonicus in the Inshore Waters of Southern Zhejiang in Summer and Autumn

鱼类摄食生态研究是海洋食物网营养动力学的主要研究内容之一,鱼类的摄食习性不仅受自身发育的影响,而且也受多种环境因素的影响。2019年8月和11月在浙江南部近海进行了渔业资源调查,共采集带鱼样品599尾,通过胃含物分析研究带鱼的食物组成及其随季节和肛长的变化,并应用典范对应分析研究带鱼摄食习性与环境因子的关系。研究结果显示,以相对重要性指数百分比的排序来看,浙江南部近海带鱼主要以鱼类、浮游幼体、等足类和磷虾类为食,摄食的饵料生物达60余种,优势饵料种类为短尾类大眼幼体、七星底灯鱼和太平洋磷虾等。此外,带鱼的摄食习性随季节和肛长发生明显变化,在夏季,带鱼摄食鱼类、浮游幼体和等足类的比例较高;秋季则主要摄食鱼类和虾类。随着肛长的增大,带鱼从摄食浮游幼体等小型饵料为主逐渐转变为摄食个体较大的鱼类饵料为主。典范对应分析结果表明,pH、海水表层温度和盐度与浙江南部近海带鱼的摄食习性有较大的相关性。研究结果进一步丰富了对浙江南部近海带鱼摄食习性的了解,可为该海域基于生态系统的渔业管理提供基础资料。

The feeding habits hairtail Trichiurus iaponicas were investigated in 599 samples in the inshore waters of southern Zhejiang province in summer and autumn of 2019 by stomach content analysis.Relationships between the feeding habits and environmental factors were evaluated by Canonical Correspondence Analysis(CCA).The results showed that the prey items of T.japonicus included more than 60 species,with dominant preys of brachyura megalopa larva,Benthosema pterotum and Euphausia pacifica.Obvious seasonal variations were revealed for T.japonicus's diet composition,with the percent index of relative importance(IRI%),pisces,planktonic larva,Isopoda and euphausiacea were higher in summer,and the IRI%of pisces and decapoda were higher in autumn.With the increase of T.japonicus's anal length,the main prey items were transferred from small size items(such as planktonic larva and small fish)to big size items(such as Larimichthys polyactis and T.japonicus).Besides,the results of CCA indicated that pH,sea surface temperature and sea surface salinity were the main environmental factors affecting the feeding habits of T.japonicus in the inshore waters of southern Zhejiang.The findings enriched the understanding of feeding habits of T.japonicus in the inshore waters of southern Zhejiang,and provided basic data for ecosystem-based fisheries management in this area.