The invasive freshwater bivalve Limnoperna fortunei in South America: multiannual changes in its predation and effects on associated benthic invertebrates

DUCHINI, D.; BOLTOVSKOY, DEMETRIO; SYLVBESTER FRANCISCO

HYDROBIOLOGIA

SPRINGER

Año: 2018 vol. 817 p. 431 - 446

0018-8158

The invasive golden mussel Limnopernafortunei is known to strongly affect benthic communitiesin South American freshwaters, but the evolution ofthese effects after the early invasion stages is poorlyunderstood. Using predator exclusion (covered with 15-and 40-mm meshes) and inclusion (unprotected) substrates,we investigated the interaction between goldenmussels and benthic invertebrate communities at differentlevels of exposure to predators in the Parana´ Riverdelta. Colonization of the substrates was largelydominated by the mussels. Oligochaeta, Nematoda,and Hirudinea were the most abundant accompanyinggroups, while Rotifera, Tardigrada, Copepoda, Cladocera,Chironomidae, Gastropoda, Hydracarina, Amphipoda,and nauplii appeared sporadically. Regardless oftheir different trophic modes and functional attributes,the numbers and biomass of associated invertebrateswere not only enhanced by protection against predators,but also by the presence of mussel colonies. Enhancementof invertebrate densities associated with musselcolonies was higher on unprotected than protectedsubstrates, suggesting that invertebrate facilitationincreases with increasing predation pressure. Comparisonswith a similar study carried out a decade earliersuggest that, after two decades of invasion, the reproductivepotential of the mussel, the predation pressureon its colonies, and its facilitation effects on otherinvertebrates have increased in the Parana´ River delta.