Invasion of Corbicula fluminea in L.: Maggiore: feeding plasticity and ability to outcompete indigenous mussel species

Corbicula fluminea is one of the most aggressive invaders worldwide. Greedy suspension feeding bivalve and engineering species, it deeply impacts colonized ecosystems. Research on spatial and temporal changes in abundance, biomass and population structure following first detection highlighted that in 3 years the invader spread to x.103ind/m2 over 1/3 of Lake Maggiore littoral area. Corbicula imposes strong competition for space and food to native mussels (i.e. Unio mancus). To predict its impact on food-web structure and nutrient cycling, we compared daily filtration rates and food spectra of the two competitors under different experimental conditions. Dietary composition and trophic niche overlap were estimated through C and N SIA of soft tissues. Results suggest that Corbicula is able to shift diet along the year. Feeding plasticity is likely of major importance for competitive advantage and success of Corbicula over indigenous species.