Ecological, behavioral and physiologic impact of the bioinvasion on native population: the case of the non-indigenous swimming crab Charybdis hellerii

Abstract

Ecological processes such as competition and predation has the potential to regulate populations, therefore influencing the functioning of the ecosystem through resource partitioning and species loss. These processes are directly related to density-dependent (DMII) or behavioral (TMII) indirect interactions. The addition of species in food webs, especially of exotic species can alter these ecological processes, which in turn will cause ripple effects, and is currently a major threat to marine biodiversity. This project will evaluate the hypothesis of bioinvasion impact on native communities. As animal model, we will use the invader crab Charybdis hellerii, which previous studies has showed to be a major competitor for resources in relation to native species. The potential deleterious effects of this invasive species will be investigated in order to assess the impacts of increasing introduction of exotic species mediated by human activity worldwide. To this will be evaluated (1) the occurrence and abundance of invasive species and the three main native species with overlapping niche (Cronius ruber, Menippe nodifrons and Callinectes danae) along the coast of São Paulo; (2) the existence of food niche overlap between native and exotic species; (3) behavioral interactions between these species; (4) the impact of density and diversity of consumers on prey populations; (5) the occurrence of physiological changes in the native species by the presence of invasive species. Thus, it is expected to contribute to increased knowledge of impacts generated by bioinvasion, providing support for the development of new research and action of administrative agencies responsible for conservation, sustainable management and use of our coastal areas. (AU)