Hydromedusan fauna of the Nansei Islands

Abstract

A total of 57 species of hydromedusae belonging to Antho-, Lepto-, Limno-, Trachy-, Narco-, and Laingiomedusae were collected at 32 stations, 1-7 stations on each of 12 islands from Tanegashima Island to Yonaguni-jima Island, in the Nansei Islands, by surface towings of a plankton net at a port, sometimes by vertical towings from 0-40 m depth at a station several km off a port, during 1991-2004. Euphysomma brevia, Koellikerina sp., Podocoryne apicula, Teissiera spp., Zanclea costata, Agastra sp., Eirene spp., Eucheilota multicirris, Eutima spp., are new to the Japanese fauna, and all but Podocoryne apicula, Eirene sp. 2, and Eucheilota multicirris, are recorded in only this region within Japan. Other, previously recorded, rare species that are known only from the Nansei Islands, are Dicnida sp., Euphysilla sp., Thecocodium quadratum, Timoides agassizii, and Kantiella enigmatica.