Crevice brittle star

Ophiopholis aculeata has a central pentagonal disc up to 2 cm (0.8 in) in diameter; this is clearly set off from the five robust, twisted arms, which are four times as long as the disc is wide. The mouth is on the oral or underside of the disc and is surrounded by five toothed jaws. The aboral or upper side of the disc is granular, and a pair of large scales, the radial shield, covers the base of each arm. The radial shield is covered with small spines which conceal the scales. The many-jointed arms are covered with more scales both on the oral and aboral surfaces; on the aboral surface there is a regular series of oval scales each surrounded by smaller scales. There are six or seven stout spines per segment, with one short spine being hooked. The colour varies, being often reddish or variegated, and sometimes purplish; the central scales on the disc often form a ten-pointed star and there are often darker bands on the arms.