Benthic hydroids (Cnidaria, Hydrozoa) from the Ross Sea (Antarctica) collected by the New Zealand Antarctic expedition BioRoss 2004 with RV Tangaroa

Abstract

During the New Zealand BioRoss 2004 survey, with RV Tangaroa, sampling of marine communities on the Ross Sea shelf was undertaken. Samples were obtained employing several sampling gears (Van Veen grab, epibenthic sled, rough bottom trawl, and beam trawl). Among the numerous benthic samples obtained, a large and important collection of hydroids was present. Sixty-one species, four of them new to science (Monocoryne antarctica sp. nov., Halecium tangaroa sp. nov., Staurotheca gracilis sp. nov. and Symplectoscyphus densus sp. nov.) have been recorded. Oswaldella blanconae sp. nov. is also described. “Anthoathecata” are represented by ten species belonging to the families Bougainvilliidae, Candelabridae, Clathrozoellidae, Hydractiniidae, Eudendriidae and Tubulariidae. Leptothecata are dominant, with 51 species belonging to the families Campanulariidae, Campanulinidae, Lafoeidae, Haleciidae, Hebellidae, Kirchenpaueriidae, Schizotrichidae, Staurothecidae, Symplectoscyphidae and Zygophylacidae. Symplectoscyphidae is the richest family with 19 species (31%), followed by Staurothecidae with eight (13%) and Haleciidae with seven species (11%). At the generic level, Symplectoscyphus with 14 species (two of them identified only at the genus level), Staurotheca with eight species (one identified to genus level) and Halecium with seven species are the most speciose genera. Twenty-two species (including the four new species) constitute new records for the Ross Sea, thus raising the number of valid, known species of the area to 77.