福建海区拥剑梭子蟹、红星梭子蟹和锈斑的食性与营养级研究

本文主要研究福建海区拥剑梭子蟹、红星梭子蟹和锈斑(虫寻)3种经济蟹类的食性与营养级.结果表明,3种蟹类胃饱满系数呈现明显的季节变化,拥剑梭子蟹、红星梭子蟹和锈斑(虫寻)胃饱满系数高峰分别出现在秋季、春季和冬季;3种蟹类皆为摄食混合饵料的动物,甲壳类和鱼类是它们的主要食物,其食性的生态类型较为接近,拥剑梭子蟹、红星梭子蟹属较典型的底栖生物食性类型,而锈斑(虫寻)的食性相对较杂.其混合饵料的营养级分别为2.38、2.59和2.60,均处于第三营养层次(低级肉食性动物).3种蟹类之间的食物的重叠指数均超过0.7,它们的食物重叠显著,对该海域的甲壳动物(主要是长尾类和短尾类)、鱼类、珊瑚虫、腹足类、底栖藻类等饵料资源存在激烈的竞争.

Study on feeding habit and nutrient level of Portunus argentatus, P. sanguinolentus and Charybdis feriatu in Fujian sea area

The feeding habit and nutrient levels of Portunus argentatus, P.sanguinolentus and Charybdis feriatus were studied in this paper. Theresultsshowed that the full coefficient in stomach of three species of crab changes in diffent seasons distinctly. The maximum of stomach full coefficient of Portunus argentatus,P.sanguinolentus and Charybdis feriatu is in auturmn,spring and winter respectively The three species of crab are omnivorous and their major preys consist of Crustacea and fish. Their feeding ecological types are similarity. The feeding type of Portunus argentatus and P.sanguinolentus belongs with typicalbenthophagous type. while that of Charybdis feriatus is more complicate.Their nutrient levels are 2.38,2.59 and 2.60 respectively, which are in the third nutrition layer(lower carnivores). The overlap index of diet among the three species of crab is over 0.7. Their foods overlap prominently, so they are in a fierce rivalry ondiets resource,such as Cousfacea (Macrura and Brachyura),fish,Anthozoa,Gastropoda and benthic algae in the Fujian sea area.