- EnglishName: Oval butterfly fish
- Local Name : Bisburu bibee
- Size : Max. 14 cm
- Family: CHAETODONTIDAE
- Order : Perciformes
- Distinctive Characters: Dorsal fin with 13-14 spines and 20-22 rays. Anal fin with 3 spines and 18-20 rays. Pectoral fin with 13-15 (usually 14) rays. Body depth 1.5-1.8 in standard length. Body with a characteristic oval shape, the dorsal and anal fins low.
- Colour: Bluish brown above, paler below. About 15 bluish stripes on sides. A black band on head running through eye. Another black band across mid caudal fin bordered by 2 yellow stripes. Snout blackish. Pectoral and pelvic fins pale yellow.
- Habitat and Biology: Found in shallow well-protected coral reef areas to depths of 20 m. Generally seen in pairs. Feeds exclusively on coral polyps.
- Distribution: Indo-Pacific.
- Remarks: Chaetodon trifasciatus is difficult to maintain in aquariums, as it feeds exclusively on coral polyps.