Decapod Crustacea from the International Indian Ocean Expedition The species of Thalassocaris (Caridea) and their larvae

Abstract

Plankton collections from the Indian Ocean contain adults and larvae of three species of Thalassocaris: T. lucida (Dana), T. crinita (Dana) and T. obscura sp.n. The new species was previously confused with T. crinita by Borradaile and with T. lucida by Kemp.Larvae of Thalassocaris are described for the first time. In each species there are 10–13 zoeal stages. The cephalothorax is very broad and shallow, the maxilla has only one coxal endite, and exopods develop on legs 1–4. T. crinita is a shallow‐water species with a wide distribution in the Indian Ocean and western Pacific. T. lucida and T. obscura are open ocean species. T. lucida is most common in the eastern Indian Ocean (and probably in the western Pacific) and is not recorded from the Arabian Sea. T. obscura is most common in the Arabian Sea and is not recorded from the south‐eastern Indian Ocean or from the Pacific.Larval characters do not support the inclusion of Thalassocaris in the Pandalidae. Recognition of the family Thalassocarididae, comprising the genera Thalassocaris and Chlorosocoides, is advocated.