The white-cheeked algae feed on silk algae. It inhabits coral reefs and rocky reefs in waters between 1 and 85 meters deep, usually in groups around rocks in surge areas.

The body of the cockroach is oval and flat on the side. The head is small and the profile of the back of the head is not particularly prominent. The mouth is small, end position, with a row of flat teeth in the upper and lower jaws, the teeth are fixed and immovable, and the tooth margins are notched. The spines of the dorsal and anal fins are sharp, and the rays are not elongated. The pectoral fins are nearly triangular, and the caudal fins are nearly truncate or concave. The body is yellow-brown to gray-brown, and the head has a brown-black eye band with the same width as the eye diameter. , there is another brown-black spot behind the band, extending down to the base of the pectoral fin, without a half-moon-shaped white spot on the snout. The dorsal and anal fins are dark brown, the fin margin is light blue, the caudal fin is light yellow with a white arc band at the base, the pectoral fin is gray-black, and the caudal peduncle spinous groove is dark brown.