滇池粘皮鯔虾虎鱼食物组成及摄食策略分析

对粘皮鯔鰕虎鱼Mugilogobius myxodermus在滇池水体的食物组成、摄食策略进行分析,初步探讨其对滇池饵料资源环境的适应性,为进一步研究其生态入侵策略积累基础资料。在东大河湿地公园湖滨带设5个采集点,2014年5月9-10日及10月10日进行了2次样品采集,分别采集到粘皮鯔鰕虎鱼17尾、130尾。滇池粘皮鯔鰕虎鱼5月份种群内以成熟个体为主,10月份转变为以幼鱼为主。粘皮鯔鰕虎鱼消化道共检出23种食物类型,主要有多种枝角类、桡足类、介形虫及摇蚊幼虫等。以出现频率评价,5月份主要摄食枝角类、桡足类、摇蚊幼虫及蛹和介形虫,10月份主要摄食枝角类、桡足类、介形虫和摇蚊幼虫;以数量百分比评价,5月份较多的饵料种类为桡足类、尖额溞、摇蚊类幼虫和网纹溞,10月份较多的饵料种类为介形虫、桡足类和摇蚊幼虫、轮虫等。初步揭示粘皮鯔鰕虎鱼入侵早期种群具有喜好底栖食物的广食性特征,但仍需进一步探索其在滇池流域广阔生境中如何在不同时空尺度上针对不同的饵料基础所采取的摄食策略的差异,深入研究其在与先期入侵的近缘种的摄食竞争中如何取得生存机会。

Food Composition and Feeding Strategies of Mugilogobius myxodermus in Lake Dianchi

Lake Dianchi in Kunming, Yunnan is the largest shallow plateau lake on the Yunnan-Guizhou plateau and is inhabited by many unique species. However, many of these species have been driven to extinction by invasive species. Mugilogobius myxodermus, one of these invasive species, has had a large negative impact on native species. To better understand the acclimation of alien fish species, the diet and feeding strategy of M. myxodermus was investigated. Specimens were collected on May 9-10 and October 10, 2014 at five sampling sites in the Dongdahe National Wetland Park, south of Danchi Lake. The collected specimens included 17 adults and 130 juveniles and a total of 23 food items were found in their guts, consisting primarily of cladocera, copepod, ostracoda and chironomid larvae. Two evaluation systems were used to assess food composition and feeding strategy. Based on occurrence frequency, the main food items were cladocera, copepod, chironomid larvae and pupae, and ostracoda in May and cladocera, copepod, ostracoda and chironomid larvae in October. However, as a fraction of total food items, consumption was primarily copepod, Alona sp., chironomid larvae, Ceriodaphnia sp. in May and ostracoda, copepod, chironomid larvae and rotifers in October. Based on the graphical method of Amundsen et al. (1996), M. myxodermus uses a general feeding strategy and mainly preys on cladocera, copepod, ostracoda and chironomid larvae, all abundant in Lake Dianchi. Because its feeding strategy is generalized foraging, M. myxodermus successfully invaded Lake Dianchi. Further study is needed to address two remaining issues: First, whether or not the species is using this feeding strategy throughout the Lake Danchi basin and, second, the intensity of food competition among the gobies of Lake Dianchi.