Description of a new montane freshwater crab (Arthropoda, Malacostraca, Decapoda, Potamonautidae) from the Eastern Cape, South Africa.

A new species of freshwater crab, Potamonautesamathole sp. nov. , is described from the Winterberg-Amathole mountain range in the Eastern Cape Province, South Africa. Morphologically, P.amathole Peer & Gouws, sp. nov. most closely resembles P.tuerkayi but can be distinguished by key morphological characters including the variation in the shape of the subterminal segment of gonopod 2 between both species. Genetically, P.amathole Peer & Gouws, sp. nov. is placed within the clade of small-bodied, mountain-dwelling crabs including P.parvispina , P.parvicorpus , P.brincki , P.tuerkayi , P.baziya , and P.depressus . The new species is found in slow-moving mountain streams and pools at high altitudes. The continued discovery and description of new freshwater crab species reinforces the need for ongoing research, especially in under-sampled regions.