Halechiniscidae (Heterotardigrada Arthrotardigrada) of Oura Bay Okinawajima Ryukyu Islands with descriptions of three new species

摘要

Marine tardigrades of the family Halechiniscidae (Heterotardigrada: Arthrotardigrada) are reported from Oura Bay, Okinawajima, one of the Ryukyu Islands, Japan, including Dipodarctus sp., Florarctus wunai >sp. n., Halechiniscus churakaagii >sp. n., Halechiniscus yanakaagii >sp. n. and Styraconyx sp. The attributes distinguishing Florarctus wunai >sp. n. from its congeners is a combination of two characters, the smooth dorsal cuticle and two small projections of the caudal alae caestus. Halechiniscus churakaagii >sp. n. is differentiated from its congeners by the combination of two characters, the robust cephalic cirrophores and the scapular processes with flat oval tips, while Halechiniscus yanakaagii >sp. n. can be identified by the laterally protruded arched double processes with acute tips situated dorsally at the level of leg I. A list of marine tardigrades reported from the Ryukyu Islands is provided.