: a class of echinoderms comprising the sea cucumbers and having a more or less elongate form usually with well-marked bilateral symmetry and differentiated dorsal and ventral surfaces, a flexible but tough and muscular body with the skeleton reduced to scattered ossicles or spicules, a water-vascular system with radial ambulacral vessels and tube feet for creeping, respiratory trees, Cuvierian organs, and strong branched tentacles about the mouth compare trepang
Word History
Etymology
New Latin, from Holothuria + -oidea
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