Potamonautid river crabs (Decapoda, Brachyura, Potamonautidae) of KwaZulu-Natal, South Africa

Abstract

The recent descriptions of Potamonautes dentatus, P. clarus and P. lividus have brought the number of species recorded from KwaZulu-Natal (South Africa) to five, with P. depressus depressus and P. sidneyi having long been known from the province. To determine and quantify levels of genetic differentiation between these species, 14 populations were analysed using allozyme electrophoresis of 14 presumptive loci. Interspecific genetic identity-values ranged between 0.224 and 0.793 (D = 0.233 to 1.495), with between one and ten fixed allele differences present among species. Morphometric differentiation between species was examined using discriminant function analyses of seven carapace and eight pereiopod variables. Species were found to be well defined along the first two canonical variables, in terms of carapace and pereiopod morphometrics. Results are discussed in light of genetic and morphometric differentiation documented for the genus. The distribution of each species was determined, using data from 220 collection localities, plotted, and discussed. A key for the identification of the species occurring in the province is provided.



WaterSA Vol.27(1) 2001: 85-98