Shallow water crabs from the Western Indian Ocean: Portunoidea and Xanthoidea excluding Pilumnidae (Crustacea Decapoda Brachyura)

During three cruises of the former Soviet research vessels R/V "Akademik Pe trovsky" (Cruise AP-14) and R/V "Odissey" (Cruises 0-33, 0-34) to the Weste rn Indian Ocean, 120 species of the superfamilies Portunoidea and Xanthoide a were collected. Species of the following families are identified in the p resent study: Portunidae (37 species), Xanthidae (64 species), Trapeziidae (12 species), Carpiliidae (1 species), Menippidae (4 species), and Xanthoid ea incertae sedis (2 species). The geographical range of 17 portunid and xa nthoid species is substantially extended, one species, Charybdis hawaiensis Edmondson 1954 was previously known only from the Pacific and is recorded for the first time from the Indian Ocean. The recent synonymy and updated d istribution records are given for all species examined, and zoogeography as well as habitat selection of the more common species are discussed.