Species of Holothuria typically have elongated, cylindrical bodies with a soft yet muscular texture and a leathery skin that may be smooth, wrinkled, or covered with small papillae (fleshy projections). Colour varies widely depending on the species—ranging from black and brown to mottled gray, red, or even patterned forms. Around the mouth are retractable, branched tentacles used to gather food from the sediment.