Relationships of Limnoperna fortunei with benthic animals

Abstract

Similar to other invasive bivalves, Limnoperna fortunei has a variety of effects on non-fish animals. These effects have been studied in the Paraná-Paraguay-Uruguay rivers system Río de la Plata, and in Embalse Río Tercero since the invasion of South America by the bivalve. The bulk of information accumulated indicates that L. fortunei has predominantly positive effects on meiofaunal groups. Increases in the abundance, biomass, and richness of a large number of groups are attributed to substrate enrichment with the bivalve?s feces and pseudofeces and refugia provision amid the valves. Nevertheless, negative impacts on some groups (gastropods) and the homogenization of benthic faunas following colonization by the mussel have been reported. Large-size invertebrates might also be detrimentally affected through biofouling by the mussel, as severe cases of overgrowth have been reported for native crabs and mussels, and for the invasive clam Corbicula fluminea. Yet, the long-time consequences to affected individuals and impacts at the population level have not been assessed. A variety of animals including crabs, turtles, likely waterfowls, and some mammals may benefit from predation on this new abundant alimentary item, although the consequences to their populations remain also unstudied. Despite marked similarities with Dreissena polymorpha, there are a number of differences regarding the effects of the two bivalves arising from differences in their biology and ambient dissimilarities between the environments colonized. The extrapolation of results obtained for Dreissena, abundant in the Limnoperna literature, can be misleading due to these differences.