Distinctive Characters: Dorsal fin with 12-14 spines and 14-16 rays. Anal fin with 4-5 spines and 13-15 rays. Pectoral fin with 15 rays. Body depth 1.7-2.2 in standard length. Body elongate. The dorsal and anal fins angular.
Colour: Overall white with narrow chevron markings on sides. Basal two-thirds of caudal fin blackish in adults; yellow in juveniles. A black bar through eyes.
Habitat and Biology: Usually found on reef edges and upper slopes at depths of 2-20 m. Aggressively defends a small territory of table coral on which it feeds.
Remarks: Chaetodon trifascialis is an obligate coralivore, and also is not recommended as an aquarium fish