Predation preference of signal crayfish ( <i>Pacifastacus leniusculus</i> ) on native and invasive bivalve species

Predatory, non-native fauna can influence biodiversity and trophic dynamics in invaded ecosystems. Signal crayfish (Pacifastacus leniusculus) are a highly successful invader, which have altered freshwater benthic communities, including bivalve populations. Bivalves keystone group global decline, partly due to invasion by alien species. However, little is known about the predatory impacts of invasive within co-occurring native Mesocosm predation choice experiments considered relative signal rates between paired (Anodonta anatina Unio tumidus) (Dreissena polymorpha, D. bugensis, Corbicula fluminea) bivalves, bivalves. All bivalves were actively predated, but there was no consistent difference biomass versus consumed. effects consumption consistently different; 18.2% lethally with 100% surviving individuals remaining undamaged, whereas 1.1% received nonlethal damage form shell chipping, could reduce long-term fitness natural environments. In considering species, polymorpha more resistant when compared other taxa tested. The majority field research aquatic invasions considers purely lethal inferred from invertebrate presence/absence. These demonstrate need better understand both processes may include substantial on life history endangered taxa.