Registered: July 2003
Scientific Name: Pomacanthus imperator
Max. size: 40.0 cm SL (male/unsexed)
Environment: reef-associated; non-migratory; marine; depth range 1 - 100 m
Distribution: Indo-Pacific = Red Sea and East Africa to the Hawaiian, Line and Tuamoto islands, north to southern Japan and the Ogasawara Islands, south to the Great Barrier Reef, New Caledonia, and the Austral Islands. Not found in Easter Island, Rapa and the Marquesan Islands.
Morphology: Dorsal spines (total): 13-14; Dorsal soft rays (total): 17-21; Anal spines: 3; Anal soft rays: 18-21. Juveniles are bluish black with concentric white circles. Adults are blue with close-set horizontal yellow stripes on the sides and the adjoining dorsal and anal fins. Snout white; eye enclosed in a black vertical bar with blue edge; pectoral fin base area also black. Transformation to the adult color pattern occurs over the size range 8 - 12 cm.
Biology: Juveniles are encountered under ledges, or in holes of outer lagoon patch reefs or semi-protected areas of exposed channels and outer reef flats. Subadults move to reef front holes and surge channels. Large adults inhabit ledges and caves in areas of rich coral growth on clear lagoon, channel, or seaward reefs. Feeds on sponges and other encrusting organisms; also on tunicates. Forms pairs. Young and adults may clean much larger fishes such as sunfish. Frequently exported through the aquarium trade. Juveniles are distinguished by a white dorsal-fin margin.
Aquarium Care: Will nip at Tridacnid clams, LPS, soft corals like Xenia. Usually can be kept with SPS and more noxious softies. Small adults and juveniles make good inhabitants. Larger adults can be more prone to parasites and become poor feeders. Adults are also prone to loss of color and HLLE.