A New Species of Parapetulus (Copepoda : Caligidae) Parasitic on the Samson Fish, Seriola hippos from Australia and Its Similarity with Caligus spinosus

摘要

Parapetulus spinosus, new species, was recovered from the gill arches of the samson fish Seriola hippos Gunther. The female of this species, although grossly different in its genital complex and abdomen, is otherwise virtually identical with Caligus spinosus Yamaguti, which was found on the same host. Also, the male of the new species appears to be identical in every detail with the males described from C. spinosus. The similarities are explained by divergent evolution on one host species. A proposal to relagate Caligus kurochkini Kazatchenko to the genus Parapetulus is given, bringing the Australian records of the genus to three species.