A small, brilliantly colored star to about 8 cm (3 in) across, red through orange, its upper surface tiled with flat plates that give it a neat mosaic look rather than the granular or spiny finish of larger species. Arm tips are often darker than the disc, and the whole animal is stiff and flattened, built to lie against rock rather than to hump over it.
It lives on hard coral surfaces and rubble from about 1 m to 30 m (3 to 100 ft), grazing the film of algae and detritus that coats them. Mortensen described it in 1938 from material collected at Hurghada, and the epithet is that town's older name, Ghardaqa - a rare case of a reef animal carrying an Egyptian place name. Records cluster almost entirely in this sea and the 🌊 Gulf of Aden, which makes it about as close to a local endemic as an echinoderm gets here. Small, common and photogenic, it is one of the first stars a diver learns to recognize on these reefs.
- small bright red to orange star
- flat plates over the whole upper surface
- arm tips often darker than the disc
- diameter up to 8 cm
