First record of Holothuria (Cystipus) dura (Echinodermata: Holothuroidea) from Japan, with notes on locomotion

Abstract

The sea cucumber, Holothuria (Cystipus) dura Cherbonnier and Féral, 1981, previously known only from the Philippines and New Caledonia, is newly recorded from Japanese waters; this is also the first record of the subgenus Cystipus from Japan. The two specimens described here were collected from the sublittoral bottoms near Hahajima island (126-261 m depth) and Okinoshima island (100-120 m depth). The morphology of the Japanese specimens is briefly described. In-situ photographs of the living individuals and scanning electron micrographs (SEM) of ossicles are provided for the first time for this species. The table ossicles in the dorsal body and in the papillae are highly modified fenestrated spheroids that have not been depicted previously. Some of the ventrolateral conical papillae, especially those in the middle part of the body, were bifurcated, perhaps indicative of increased surface area against the bottom for powerful propulsion while 'walking. Some notes on locomotion are given, inferred from the in-situ photographs and the morphology of the ventrolateral conical papillae.