Evaluating the role of predatory fish controlling the invasion of the Asian golden mussel (Limnoperna fortunei) in a subtropical river

1. The invasive Asian golden mussel (Limnoperna fortunei) is continuously expanding through South America, altering the aquatic ecosystem structure and functioning. While several native fish species predate on this mussel, these interactions, and their consequences for the food web, have not been studied in depth. 2. We combine a survey of the fish assemblage trophic structure using gut contents and stable isotope analysis with an in situ exclusion experiment in order to: (i) determine the main fish species predating on L. fortunei; (ii) estimate the contribution of L. fortunei to the biomass of fish assemblage; and (iii) evaluate the role of fish on the density and maximum shell length of L. fortunei in the lower Uruguay River (the Río de La Plata Basin). 3. We found that about one-third of the fish species in the assemblage (28 out of 81 species) consumed L. fortunei, which was an important food item (>10% of the dietary volume and >30% of frequency of occurrence) for 11 fish s...1. 入侵性亚洲金贻贝（Limnoperna fortunei）正持续在南美洲扩散，改变着水生生态系统的结构与功能。尽管已有多种本土鱼类以该贻贝为食，但二者的捕食关系及其对食物网的影响尚未得到深入研究。 2. 本研究结合基于胃含物分析（gut contents analysis）与稳定同位素分析（stable isotope analysis）的鱼类群落营养结构调查，以及原位排他实验（in situ exclusion experiment），旨在实现以下三项目标：（i）明确以亚洲金贻贝为食的主要鱼类物种；（ii）估算亚洲金贻贝在鱼类群落生物量中的贡献占比；（iii）在乌拉圭河下游（拉普拉塔河盆地）评估鱼类对亚洲金贻贝种群密度及最大壳长的调控作用。 3. 研究结果显示，该鱼类群落中约三分之一的物种（81种中的28种）会取食亚洲金贻贝；其中11种鱼类的食物组成中，该贻贝为重要食物类群（日粮体积占比＞10%，出现频率＞30%）……