Description

 This sea cucumber has a cylindrical body of up to 25 cm and has a flattened ventral side, which bears numerous tube feet in three or four longitudinal rows. It has raised conical papillae on its dorsal surface, with about 20 stumpy, branched tentacles around its mouth. The dorsal surface is dark brown or black and the underside is usually paler, often yellow. It derives its common name from the habit of discharging a mass of sticky white threads (the Cuvarian organs or cotton glands) when roughly handled, the threads being designed to entangle and disorientate potential predators.