A big flexible sand star with more than five arms, out on open sediment after dark.
A large sea star with a small disc and long, flat, flexible arms, commonly seven, eight or nine of them in this region, and often twenty to fifty centimetres across. The upper surface is covered in paxillae, small pillars each topped with a tuft of granules, giving a matte texture; colour runs grey-brown, olive, fawn and purple-grey, sometimes with darker banding along the arms. The margin is not edged by the two rows of squared plates that give Astropecten its combed outline, and the whole animal is flatter and considerably more flexible, so an arm follows the shape of the ground rather than standing off it.
The tube feet are pointed and have no suckers, which suits pushing through sediment rather than gripping rock. It lies just under the surface by day and comes out onto open ground at night, moving faster than a sea star is expected to move and leaving a broad shallow trail. Prey is swallowed whole and the remains are ejected afterwards rather than digested outside the body; brittle stars are taken heavily, along with small bivalves, snails and other echinoderms.
Arms are shed easily, at the disc as well as partway along, and a large proportion of the animals seen carry at least one short regrowing arm. Species are separated on plate and spine detail and this entry is pitched at the genus; Luidia maculata is the name most often attached to the large eight-armed animals photographed in the region, frequently without the characters having been checked. Recorded from about 3 to 35 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.