无量山中段泽陆蛙和饰纹姬蛙食性分析

An Analysis on Feeding Habits of Fejervarya Multistriata and Microhyla Fissipes in the Middle Segment of Wuliang Mountain

对收集自云南省镇沅县无量山中段的镇沅县境内相似生境的355号泽陆蛙和144号饰纹姬蛙食物胃容物作食性研究,分析其食性组成及食物多样性差异。结果表明:泽陆蛙和饰纹姬蛙主要以动物性食物为主,泽陆蛙食物包括3门6纲19目,饰纹姬蛙食物包括1门2纲7目。对2种蛙进行食物多样性比较,泽陆蛙食物多样性指数为9.425,饰纹姬蛙食物多样性指数为1.473,泽陆蛙的食物多样性是饰纹姬蛙的7倍。泽陆蛙的体型大,颌宽,能取食的猎物就广泛,而饰纹姬蛙的体型偏小,颌窄限制了它只能取食小型昆虫类,因此体型差异是导致他们食物多样性存在差异的主要原因。2种蛙的食物生态位重叠度达到0.6736,说明存在食物竞争关系,而从食物多样性及食物量百分比来看,饰纹姬蛙的食性单一,食物组成主要是膜翅目和等翅目等蚁科昆虫(占98%),说明体型的差异导致的食性差异已经让同域分布的两个物种从食物组成上产生了生态位分化。

A total of 355 stomachs of Fejervarya multistriata and 144 stomachs of Microhyla fissipes were collected from the same habitat in the middle segment of Wuliang Mountain,Zhenyuan County,Yunnan Province.Stomach contents were studied to analyze the differences in feeding habits and food diversity.The results showed that F.multistriata and M.fissipes principally feed on animal food.Food items of F.multistriata include 3 phyla,6 classes,19 orders,while food items of M.fissipes include 1 phylum,2 classes,7 orders.The comparison of food diversity between 2 species showed that the food diversity index of F.multistriata was 9.425 and M.fissipes was 1.473.The food diversity of F.multistriata was 7 times higher than that of the M.fissipes.F.multistriata is equipped with larger body size and wider jaw,which leads to a larger variety of diet selection,while the smaller body size and narrower jaw of M.fissipes limits its food size.It was derived that the different breadths of trophic niches were likely due to differentiated body size.The food niche overlap of 2 species was 0.6736,which indicated competition for food resources.However,from the perspective of food diversity and the proportion of food items,the feeding habit of the M.fissipes is monotonous.The food composition of M.fissipes is mainly Hymenoptera and Isoptera and other ant-like insects,accounting for 98%.The results underline that trophic niche differentiation between 2 sympatric species,which is likely contributed by their morphological divergence of body size.