Biochemical and morphological evidence for a new species of river crab potamonautes parvispina sp. Nov. (Brachyura, Potamonautidae)

Potamonautid river crabs were collected from four sites along the Olifants River in the Western Cape, South Africa in order to determine morphological and genetic differentiation among these populations. Two distinct forms were identified, and fixed allele differences at some allozyme loci between sympatric populations of the two forms confirmed that they were reproductively isolated. It was concluded that these forms represent two species, one of which was previously unknown, and is described in this paper as Potamonautes parvispina sp. nov.