Morphological and molecular evidence confirm the occurrence of the threatened annual fish Garcialebias reicherti (Loureiro & Garcia 2004) (Rivulidae) in Brazil

Garcialebias is the most representative genus of the Austrolebias genus group, comprising 16 species, 14 of which are recorded in Brazil. Most of these are rare and are restricted-range species facing a severe threat of extinction. Garcialebias reicherti is endemic to drainages associated with the Mirin lagoon in Uruguay. However, preliminary studies suggested that the species is also present in Brazilian territory. In this study, the analysis of morphological and molecular characters confirms the occurrence of the species in Brazil. Individuals of G. reicherti collected in the Jaguarão River basin exhibited all the diagnostic characteristics of the species, and molecular analyses revealed that these individuals clustered with the Uruguayan populations of G. reicherti, forming together a well-supported monophyletic group. In total, seven temporary wetlands with the presence of G. reicherti were recorded in Brazil, distributed along the lower course of the Jaguarão River and its tributary. As in Uruguay, the species should likewise be considered endangered in Brazil.