A New Species of Burrowing Crayfish in Genus Parastacus Huxley, 1879 (Decapoda, Parastacidae) from the Sinos River Basin, Southern Brazil

In this contribution, we describe a new species of burrowing crayfish of the genus Parastacus from a swamp forest in the state of Rio Grande do Sul, southern Brazil, and evaluate its conservation status according to the IUCN Red List Criteria (sub-criterion B1). Parastacus macanudo sp. nov. differs from all other congeneric species in that it has a single row of verrucous tubercles irregularly distributed in the dorsal surface of the palm of chelipeds and epistome median section with a longitudinal groove. The extent of occurrence (EOO) was estimated to be similar to 1,312 km(2) and the species was recorded in only one location in the Sinos River basin. The main threat identified was a continued decline in habitat quality, resulting from pollution in the river and deforestation. We know only one point of occurrence of Parastacus macanudo sp. nov., and suggest that it be categorized as Data Deficient.