Which factors determine non-indigenous fish dispersal? A study of the red piranha in tropical Brazilian lakes

Fish introductions are common worldwide and are responsible for economic and ecological damage (Welcomme 1988). Non-indigenous fish have been the leading cause of the extinction of fish species in North America (Miller et al. 1989) and worldwide (Mooney and Cleland 2001). In Brazil, fish introductions are common; they may cause the local extinction of indigenous fish species and contribute to biodiversity decline and biotic homogenization (Latini and Petrere 2004, Agostinho et al. 2005). Nowadays, 134 freshwater fish are endangered in Brazil due to pollution, siltation, impoundments and flood control, fisheries, and introductions of non-indigenous species (NIS) (Agostinho et al. 2005).