POMACANTHIDAE Pomacanthus semicirculatus (photo by Baramee Temboonkiat) Pomacanthus semicirculatus (Cuvier, 1831) Semicircle Angelfish D XIII, 20-23; A III, 18-22; P1 19-21; LLp 65-70; LR 78-82; GR 4-5 + 12-13. Body oblong, very deep and compressed; a long spine at corner of preopercle. Outer posterior part of dorsal and anal fins prolonged as filaments; caudal fin slightly rounded. Color: anterior and posterior third of body brownish, middle portion greenish to yellowish; blue margin on edges of preoperculum, operculum, and all fins except pectorals; numerous small blue spots on body and median fins. Juveniles blackish with about 12 alternating narrow blue and white bars on head and body, bars progressively more curved posteriorly. Size: maximum length about 40 cm. Distribution: Indo-Pacific, from East Africa to Samoa. Remarks: inhabits coral reefs and rocky reefs at depths of 5-30 m. Found solitary or in pairs. Feeds on sponges and tunicates.