Exceeding its own limits: range expansion in Argentina of the globally invasive apple snail Pomacea canaliculata

Abstract

Pomacea canaliculata is a freshwater snail native to southern South America. The aims of this work are to update its distribution in Argentina and to analyze through niche models whether the environmental conditions from its original distribution can anticipate its recently expanded range. Almost all records of P. canaliculata before 1958 (original records) belong to del Plata or connected basins. A quarter of the new present records are located in basins not connected to del Plata, indicating a recent expansion of the distribution range of P. canaliculata in Argentina. Recently colonized areas are mostly environmentally suitable according to the projection of the original distribution model, thus natural barriers were probably the main limits to its distribution in the past. According to the model, many regions outside its original range, including several not yet colonized, are suitable for the establishment of P. canaliculata. Consequently, it is likely that this species will continue establishing new populations in Argentina, especially if fishermen and aquarists continue to move snails to new locations. Our study revealed that an extensive but overlooked invasion is in process in its native range, where the impacts on diversity and ecosystems functioning may differ from those already described elsewhere.