The members of the family Chaetodontidae, popularly know as butterflyfishes, coralfishes and bannerfishes. Most species of butterflyfish live in the warm tropical seas of the Indo-Pacific (about 90%) with the remainder in the Atlantic. Only a few species are found in subtropical waters, bordering onto subtemperate zones. The butterflyfish have a highly compressed body in which the back is raised , forming an elongate-oval to near circular shape in some; a small protactible mouth with brush-like teeth in the jaws; a continuous dorsal fin with strong and sharp spines in the anterior section, followed by a large-surface soft part; an anal fin mirroring the soft part of the dorsal fin , headed by 3-5 strong spines, of which the 2nd is often greatly enlarged.
Place of origin:Central Pacific
Central South Pacific, known from the Society Islands, Tahiti region and the Marquesas Islands. Occurs in sheltered reefs in the shallows to about 25m depth. Like its close relative Chaetodon kleinii, it occurs in small aggregations where common. C.trichrous does not overlap in its geographical range with widespread C.kleinii and whilst the shape and similar colour patterns suggest their close relationship, they are easily identified by their differences. A small species largest reported is 12cm, but usually about 10cm.