A new species of freshwater crab (Decapoda, Potamonautidae) from the swamp forests of KwaZulu-Natal, South Africa: Biochemical and morphological evidence

Potamonautid river crabs were collected from five localities in northeastern KwaZulu-Natal to determine biochemical and morphological differentiation among these populations. Two distinct forms were included in these collections. One of the forms could be identified as Potamonautes sidneyi, whereas the ether was previously unknown. Biochemical analysis of 21 presumptive allozyme loci showed the two forms to be distinct, separating at a genetic identity value of 0.829. A fixed allele difference at the HEX locus in the sympatric populations of the two forms indicated that they were reproductively isolated. Morphometric analysis of seven carapace variables, by means of a discriminant function analysis, showed the two forms to be distinct. The unidentified form, which appears to be confined to patches of swamp forest in northeastern KwaZulu-Natal, is described in this paper as Potamonautes lividus sp. nov.