It is best to eat seaweed on the moontail, because the moontail is a tropical fish that eats algae. It generally lives in coral reef areas and rocky reef areas in tropical waters with a water depth of 2-40 meters, usually in groups at the bottom of the area, and the number of groups is 5 or more.

The body of the fish hung at the end of the moon 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 none of the fin rays are elongated. The body is uniform blue-gray, the pelvic fins are purple-black with white margins, the remaining fins are the same color as the body, the dorsal, anal and caudal fins all have bright blue margins, and the tail spines are blue-black. The juvenile moontail fish has a blue-gray body, yellow dorsal ridges, purple anal fins, and a yellow fringe at the end of the caudal fin. The body turns a uniform bluish-gray as it grows.