CHAETODONTIDAE Chaetodon trifasciatus (photo by Ukkrit Satapoomin) Chaetodon trifasciatus Park, 1797 Oval Butterflyfish D XIII-XIV, 20-22; A III, 18-21; P1 13-15; LLp 30-36; LR 34-39. Body oval; snout short and blunt; predorsal contour slightly convex. Lateral line incomplete. Caudal fin truncate, edges rounded. Color: yellow to grayish yellow, becoming darker dorsally, with narrow slightly oblique purplish stripes on body; anal fin golden orange with a broad yellow-edged black band at base of the fin; a yellow-edged purplish-gray band at base of soft portion of dorsal fin; a broad yellow band crossing caudal peduncle and yellow-edged black band across middle of caudal fin; a yellow-edged black bar through eye. Size: maximum length about 15 cm. Distribution: Indian Ocean, from East Africa to Bali. Remarks: Chaetodon lunulatus is its Pacific sibling.