The freshwater fishes from the Costa Verde Fluminense region of southeastern Brazil

The region between the Brazilian Shield and Atlantic Ocean is characterized by presence of numerous hydrographic basins isolated mountainous terrain that flow directly into ocean without forming wide coastal plains. However, knowledge about diversity distribution freshwater fish in several areas still incipient. One these Costa Verde Fluminense region, situated municipalities Mangaratiba Paraty State Rio de Janeiro. In order to eliminate gap fauna this we prepared a list species, dichotomous identification keys illustrations all species. We examined material from expeditions carried out 1942 2019, deposited Ichthyological Collection Museu Nacional, Universidade Federal do Janeiro, Brazil. comes 29 continental rivers four drainages on Ilha Grande island. recognized 54 species belonging 16 families 9 orders. Siluriformes was most diverse with 18 followed Characiformes 14 Cyprinodontiformes 10 Cichliformes Gobiiformes three Syngnathiformes two Gymnotiformes, Salmoniformes Synbranchiformes one each. These records include putative undescribed introduced Phalloceros anisophallos widely distributed recorded 24 drainages. More than half (52 %) native occur exclusively streams, demonstrating importance area for biogeographic conservation studies.