云南滇池入侵虾虎鱼类的共存策略

Coexistence strategies of invaded gobies in the Dianchi Lake,Yunnan,China

虾虎鱼类是入侵种的一个重要来源,常数种共同入侵同一区域,其种间如何实现共存是当前鱼类入侵生态学的一个重要科学问题。本研究通过形态分析、空间分布调查及摄食分析等方法,从形态分化和生态位分化角度揭示滇池新入侵的粘皮鯔虾虎鱼与先期入侵近缘种的共存策略。结果表明:粘皮鯔虾虎鱼与小黄黝鱼、子陵吻虾虎鱼、波氏吻虾虎鱼等先期入侵种在形态上存在显著差异。其空间分布在研究区域上与上述物种存在显著差异,空间生态位指数显著高于其余物种。摄食分析显示,粘皮鯔虾虎鱼的食物多样性指数显著高于其余物种;其主要摄食种类为圆形盘肠溞和腺介虫等,与其他虾虎鱼类主要摄食种类也存在明显差异。在摄食生态位上,滇池入侵虾虎鱼类存在显著分化。这说明形态差异、空间生态位分化及营养生态位分化降低了种间竞争强度,促进了粘皮鯔虾虎鱼与先期入侵虾虎鱼类实现共存。粘皮鯔虾虎鱼可能凭借摄食策略上的优势在种群数量、占据栖息地范围上优于竞争对手,成为研究区域入侵虾虎鱼类中的优势种群。

Gobiids are widespread invasive species,with many species from this group usually invade into the same ecosystem simultaneously.Understanding the mechanisms underlying the coexi-stence of different gobiid species in the sympatric habitats is a key issue in fish invasion ecology.Incorporating morphological analyses,spatial distribution survey,and trophic analyses,we examined the coexistence strategy of Mugilogobius myxodermus and related species(the earlier invaders)in Dianchi Lake,Yunnan,China.Our results showed significant differences in morphology and spatial distribution among the four invasive gobies species(i.e.,M.myxodermus,Micropercops swinhonis,Rhinogobius giurinus and Rhinogobius cliffordpopei).The spatial niche index of M.myxodermus was the highest.Food composition between M.myxodermus and other gobies was significantly different,with the former mainly feeding on Chydorus ovalis and Cypris sp.The trophic diversity index of M.myxodermus was the highest.Overall,we found that morphological differences,spatial niche diffe-rentiation,and trophic niche differentiation contributed to the coexistence of the gobies in Dianchi Lake,which could help M.myxodermus reduce interspecific competition.Importantly,the feeding strategy is the key factor determining population size and habitas of M.myxodermus during their competition with the other gobies,and finally contributing to the dominant position in the study area.