ASSIGNMENT OF HOMARUS-CAPENSIS (HERBST, 1792), THE CAPE LOBSTER OF SOUTH-AFRICA, TO THE NEW GENUS HOMARINUS (DECAPODA, NEPHROPIDAE)

Three species of nephroid lobsters have been recognized in the genus H omarus: the American and European lobsters, H. americanus and H. gamma rus of the northwestern and northeastern Atlantic, respectively, and t he Cape lobster of South Africa, H. capensis, few specimens of which h ave been studied until recently. Analysis of new specimens allows reco nsideration of the systematic status of this species and a subsequent transfer to a monotypic new genus Homarinus. Far smaller than its nort hern relatives, with a maximum observed carapace length of 47 mm, the Cape lobster has first chelae adorned with a thick mat of plumose seta e and less abundant setae on the carapace, tail fan, and abdominal ple ura, whereas these setae are absent in Homarus. Relative length and sh ape of the carpus on pereopod 1, tooth pattern on cutting edges of fir st chelae, shape of the linguiform rostrum, large size of oviducal ope nings, and structure of male pleopods differ from corresponding featur es in Homarus. Comparative analysis of DNA from the mitochondrial 16s rRNA gene demonstrated considerable sequence divergence of the Cape lo bster (9.7%) from its putative congeners. The magnitude of this estima te relative to that between the two North Atlantic species (1.3%) furt her suggests that taxonomic revision is warranted.