Freshwater crabs (Decapoda: Brachyura: Pseudothelphusidae, Trichodactylidae) from the state of Roraima, Brazil: species composition, distribution and new records

ABSTRACT: The species composition and distribution of the pseudothelphusid and trichodactylid freshwater crabs from the state of Roraima, Brazil, are updated based mainly on documented records deposited in the collections of the Instituto Nacional de Pesquisas da Amazônia (Manaus) and the Museu Integrado de Roraima (Boa Vista). This paper provides records for the occurrence of ten species (six Pseudothelphusidae, four Trichodactylidae). Three species are recorded from Roraima for the first time: the pseudothelphusids Fredius beccarii (Coifmann, 1939) and Fredius fittkaui (Bott, 1967), and the trichodactylid Moreirocarcinus laevifrons (Moreira, 1901). The records of F. beccarii also represent the first documented occurrence of the species in Brazil. All species in the state are presented in maps that document their geographic distribution. Comments are made on the diversity of the Branco River crab fauna in comparision with diversity in other sub-basins of the Amazon River.