Beneath the surface: two new burrowing crayfish species of Parastacus Huxley, 1879 (Malacostraca, Decapoda, Parastacidae) from the Mirim-São Gonçalo Basin, southern Brazil

Abstract

Abstract In this contribution, we describe two new species of burrowing crayfish from the countryside of the municipality of Pelotas in the south region of the state of Rio Grande do Sul, southern Brazil. We evaluated morphology and also their conservation status according to the IUCN Red List Criteria. Parastacus schubarti sp. nov. differs from the burrowing species of Rio Grande do Sul state in having an epistome anteromedian lobe septagonal, areola wide, and by the large spines in telson lateral margins. Parastacus dincaoi sp. nov. is distinguishable from the burrowing species of Rio Grande do Sul state in having a wide pleon and a subtriangular telson with small blunt spines on lateral margins. The extent of occurrence of P. schubarti sp. nov. and P. dincaoi sp. nov. were estimated at 382 km2 and 963 km2, respectively. The main threats identified were continued decline in the habitat quality, resulting from deforestation, habitat fragmentation, agriculture and livestock. However, as we currently know only one point of occurrence for each new species, we suggest that both be categorized as Data Deficient.