Abstract. — Three species of 

 nephropid lobsters have been rec- 

 ognized in the genus Homarus: the 

 American and European lobsters, 

 H. americanus and H. gammarus 

 of the northwestern and northeast- 

 ern 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 subse- 

 quent 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 mito- 

 chondrial 16s rRNA gene demon- 

 strated considerable sequence di- 

 vergence of the Cape lobster (9.7%) 

 from its putative congeners. The 

 magnitude of this estimate relative 

 to that between the two North At- 

 lantic species (1.3%) further sug- 

 gests that taxonomic revision is 

 warranted. 



Assignment of Homarus capensis 

 (Herbst, 1 792), the Cape lobster of 

 South Africa, to the new genus 

 Homarinus (Decapoda: Nephropidae) 



Irv Kornfield 



Department of Zoology and Center for Marine Studies 

 University of Maine, Orono. Maine 04469 



Austin B. Williams 



National Marine Fisheries Service Systematics Laboratory 

 National Museum of Natural History. Smithsonian Institution 

 Washington, DC 20560 



Robert S. Steneck 



Department of Oceanography and Ira C. Darling Center 

 University of Maine, Walpole, Maine 04573 



Manuscript accepted 25 September 1994. 

 Fishery Bulletin 93:97-102 (1995). 



Until now, three species of neph- 

 ropid lobsters have been recognized 

 in the genus Homarus Weber, 1795 

 (see Holthuis, 1991)://. americanus 

 H. Milne-Edwards, 1837, the north- 

 western Atlantic American lobster; 

 H. gammarus (Linnaeus, 1758), the 

 northeastern Atlantic-Mediterra- 

 nean European lobster; andH. cap- 

 ensis (Herbst, 1792), the South Af- 

 rican Cape lobster. All are found in 

 cool or cold temperate waters, and 

 the North Atlantic species range 

 into subarctic waters. The northern 

 H. americanus and H. gammarus 

 are well-known, abundant, and eco- 

 nomically valuable species, but the 

 southern H. capensis has long been 

 problematic because only a few 

 specimens (13 males, 1 female) were 

 known to exist in collections 

 (Barnard, 1950; Wolff, 1978; Hol- 

 thuis, 1991). Gilchrist (1918) had 

 seen only three specimens and re- 

 marked (p. 46) that "it is a very rare 

 species, and is not even known to 

 Cape Fishermen." Kensley (1981) 

 recorded its distribution in the Cape 

 Province as Table Bay to East Lon- 

 don, and recent new collections ex- 



tend the range to Transkei (Kado et 

 al., 1994). 



Regardless of its rarity, sufficient 

 specimens of the Cape lobster, liv- 

 ing and preserved, are now avail- 

 able for analysis of its distribution, 

 morphological, and genetic at- 

 tributes, and systematic status. 

 Results of our studies indicate that 

 this species should be removed from 

 Homarus and placed in a genus of 

 its own; this paper provides sup- 

 porting evidence for this action and 

 offers supplementary descriptive 

 information on the species. 



Homarinus, new genus 

 Figs. 1-4 



Type species — Homarus capensis 

 (Herbst, 1792) by present designa- 

 tion and monotypy. 



Description — Carapace moderately 

 compressed, narrower than deep, 

 sparsely setose, middorsal carina 

 barely evident on gastric region, ob- 

 solescent on thoracic region posterior 

 to deep cervical groove. Rostrum 



97 



