Habitat: Marine. Inshore and offshore coral reef tops. Found within caves at night. Often found in tangles of staghorn coral or anywhere there is abundant algae on reefs. Natural History Notes: Territorial herbivore. Pugnaciously guards large territories, will chase and nip intruders of all sizes. Feeds mainly on algae but also on harpacticoid copepods, small gastropods, eggs of mollusks, sponges, polychaetes and hydroids. Juveniles subsist on the external parasites of fishes. Depth: 1 - 30m Characteristics: Adults brownish gray with yellowish cast, yellow-gold crescent above eyes. Black saddle on upper base of tail. Vertical dark lines following scale rows. Blackish spot covering most of pectoral base. Yellow-gold crescent above eyes. Juveniles: bright yellow with a large black spot at base of dorsal fin and dorsally on caudal peduncle.