Elpidiidae is a family of deep-sea sea cucumbers.
They have a translucent body with long and stout podia acting like legs. The mouth is surrounded by thick and short oral tentacles, and the dorsal part often shows pairs of elongated podia as well, pointing upwards. Some species can also show swimming appendages on top of the mouth. Sea pigs live in the darkest parts of the ocean. When introduced to warm waters, their bodies disintegrate, making them vulnerable to sudden heat changes.
Genera The following genera are recognised in the family Elpidiidae: Achlyonice Théel, 1879 Amperima Pawson, 1965 Ellipinion Hérouard, 1923 Elpidia Théel, 1876 Irpa Danielssen & Koren, 1878 Kolga Danielssen & Koren, 1879 Peniagone Théel, 1882 Penilpidia Gebruk, 1988 Protelpidia Gebruk, 1983 Psychrelpidia Hérouard, 1923 Psychroplanes Gebruk, 1988 Rhipidothuria Hérouard, 1901 Scotoplanes Théel, 1882
References