Assignment of Homarus capensis (Herbst, 1792), the Cape lobster of South Africa, to the new genus Homarinus (Decapoda: Nephropidae)

—Three species of nephropid lobsters have been recognized in the genus Homarus: the American and European lobsters, H. americanus and H. gammarus of the northwestern and northeastern Atlantic, respectively, and the Cape lobster of South Africa, H. capensis, few specimens of which have been studied until recently. Analysis of new specimens allows reconsideration of the systematic status of this species and a subsequent transfer to a monotypic new genus Homarinus. Far smaller than its northern relatives, with a maximum observed carapace length of 47 mm, the Cape lobster has first chelae adorned with a thick mat of plumose setae and less abundant setae on the carapace, tail fan, and abdominal pleura, whereas these setae are absent in Homarus. Relative length and shape of the carpus on pereopod 1, tooth pattern on cutting edges of first chelae, shape of the linguiform rostrum, large size of oviducal openings, and structure of male pleopods differ from corresponding features in Homarus. Comparative analysis of DNA from the mitochondrial 16s rRNA gene demonstrated considerable sequence divergence of the Cape lobster (9.7%) from its putative congeners. The magnitude of this estimate relative to that between the two North Atlantic species (1.3%) further suggests that taxonomic revision is warranted. Assignment of Homarus capensis (Herbst, 1792), the Cape lobster of South Africa, to the new genus Homarinus (Decapoda: Nephropidae)