They are restricted to the temperate and tropical Indo-West Pacific from South Africa to Japan to Indonesia, and are exclusively marine and are absent from freshwater habitats.

Adult sleeper rays range in size from 8 to 46 cm in length and have flattened oval, circular, or pear-shaped pectoral fin discs.

The snout is moderately elongate and broadly rounded, with the rostral cartilage reduced to a slender medial rod.

The mouth is straight, very narrow, and not highly protrusible, with strong labial folds and a weak groove around the periphery.

There may be spots, blotches, or bands on the dorsal surface, but most species lack complex color patterns or ocelli.