Description

 A dark-coloured brittlestar, with a round flattish central disc up to 2.5 cm in diameter. The five, thin, flexible arms are about five times the disc diameter in length. Down both sides of each arm is a row of short, erect spines, arranged like teeth on a comb. Ophiocomina nigra moves by means of mainly horizontal movements of the arms that push against the rocky substratum.Pale, almost white, specimens may occur in any population.