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...