Increased geographical distribution and richness of non-native freshwater fish species in Argentina: evidence from a literature review

Abstract

The present study is a full review of the non-native freshwater fish species introduced into Argentina and their relationship to the main environmental features and introduction vectors of each freshwater ecoregion. The total number of non-native freshwater fish species was compiled through a literature survey; information on spatial–temporal patterns of species records and invasion vectors was retrieved for all ten freshwater ecoregions of Argentina. Our survey revealed that 18–22 non-native fish species had been recorded up to 1999, and a total of 40 introduced fish species, of which 18 are invasive and five potentially invasive, had been registered in seven Argentinean ecoregions as of May 2020. According to georeferenced records, the rainbow trout Oncorhynchus mykiss and common carp Cyprinus carpio were the non-native fish species with the greatest number of records and largest invaded areas, probably due to their species-specific ecological traits. Invasive fish species differed clearly between the Patagonia, Lower Paraná, and Lower Uruguay ecoregions, probably because of a combination of the environmental conditions, structure of native assemblages, and invasion pathways in each ecoregion. Except for the recognized impact of non-native salmonids, the adverse effects of introduced fish species have been little studied, indicating the need for further research to clarify the role of ecological shifts triggered by the introduction and establishment of non-native fish species in Argentina. In contrast to the high diversity of aquatic species and freshwater environments, the spread and impact of invasive fish species in Argentina is little known, particularly compared with other South American countries.