Calanoides natalis Brady, 1914 (Copepoda: Calanoida: Calanidae): identity and distribution in relation to coastal oceanography of the eastern Atlantic and western Indian Oceans

Until recently, Calanoides carinatus s.l. was assumed to be very widespread in the upwelling systems of the Atlantic, Indian and western Pacific Oceans. Molecular data, reported here, show that Calanoides from the eastern Atlantic and Arabian Sea are one species and distinct from C. carinatus s.s. The name Calanoides natalis Brady, 1914 is available for this species, which is fully re-described. The illustration by Brady of the male fifth leg and the currently reported genetic data lead us to conclude that C. natalis is distributed from the Bay of Biscay southwards along the eastern Atlantic, around the Cape of Good Hope, and northwards along the western boundary of the Indian Ocean as far as the Arabian Sea. A by-product of this study is the recognition that Calanoides macrocarinatus is a junior synonym of Calanoides brevicornis. Females of C. natalis are easy to distinguish morphologically from C. carinatus s.s. but are more similar to C. brevicornis, apart from size differences. From physical oceanographic evidence we conclude that the Indian Ocean is currently the upstream part of the distribution of C. natalis. Calanoides philippinensis is known to extend into the eastern Indian Ocean at tropical latitudes. It is not known if it is C. philippinensis that has been recorded along the western coast of Australia. An apparently undescribed species of Calanoides occurs on the eastern Australian coast.