Found from Japan to Alaska to Sacramento Reef, Baja California, from the low intertidal zone to 30 meters depth, in rocky habitats. Up to 10 centimeters long. White or cream in color, without spots, with rigid non-retractile tube feet in double rows, giving a bristly appearance. Has ten long yellow or white branched tentacles, which are usually retracted during daylight. In Puget Sound, eaten by the seastars Solaster stimpsoni and Leptasterias hexactis.
Sea cucumbers are soft-bodied wormlike echinoderms, having a body cylinder with a mouth at one end encircled by tentacles, and the anus at the other. They have the basic echinoderm radial symmetry, but no arms, and the echinoderm skeleton is reduced to small, scattered calcareous bonelike plates, and is usually flexible. Sea cucumbers have a water-vascular system, with or without tube feet, and respiratory trees inside the anus.
-- Peter Brueggeman