AB prepress abstract   -  DOI: https://doi.org/10.3354/ab00772

ABSTRACT: The shrimp Macrobrachium amazonicum is a widely distributed native species in South America. This study presents an updated geographic distribution of the species through a systematic review of primary and secondary data, as well and reports new native and non-native occurrences. The distribution extends approximately 4,976 km, from the Maracaibo hydrographic ecoregion (Venezuela) to Lower Paraná (Argentina), between latitudes 10°40’37” N–27°20’31” S and about 5,226 km, from the Tuira River (Panama) to Northeastern Atlantic (Rio Grande do Norte, Brazil), between longitudes 79°31’30” W–35°12’07” W. Covering much of South America and two hydrographic ecoregions in Panama, geographic expansion was detected with new continental and coastal records, both in native and non-native areas. New occurrences were recorded in the hydrographic ecoregions of Gurupi (Maranhão, Brazil); Lower Piranhas-Açu (Rio Grande do Norte, Brazil); Middle São Francisco (Bahia, Brazil); Upper Tocantins (Goiás, Brazil); Middle Paraguay (Mato Grosso do Sul, Brazil); Tarauacá (Amazonas, Brazil); Maracaibo, Trinidad, and Orinoco (Venezuela); Magdalena-Sinu (Colombia); Chagres (Panama); and the High Andes of the Amazon (Bolivia). The new record in Maracaibo extended the species' range by 361 km to the north, and in Chagres, Panama, in Central America, by 51 km to the west. Macrobrachium amazonicum exhibited the neotropical distribution which was already known for the species. Evidence of anthropogenic introduction in Brazilian reservoirs is supported by the absence of records in connection sites with the Orinoco and Amazon basins, which are geologically separated from the La Plata basin. The wide distribution of the species highlights its high adaptability to various environments.