Saddleback Butterflyfish.

The Black-wedged Butterflyfish, Chaetodon falcula, is a species of butterflyfish (family Chaetodontidae). IT is found in the Indian Ocean, from eastern Africa south to 27°S and east to Indonesia.

It grows to a maximum of 20 cm (nearly 8 in) long. Its shape is reminiscent of longsnout butterflyfish, though the snout is not as extremely prolonged and the pattern is very different. The body is white with a series of narrow vertical dark grey lines and bright yellow and orange over the back, dorsal fin, anal fin and caudal fin. There are two well-defined black saddles on the back, and as usual the characteristic black eye-band of Chaetodon is present.

The Black-wedged Butterflyfish is found on the reef edge and upper slope. It prefers current-prone habitats 1-20 m deep. It mainly feeds on invertebrates.

It belongs to the large subgenus Rabdophorus which might warrant recognition as a distinct genus. In this group, the closest relative of this peculiar species is the similar-looking Pacific Double-saddle Butterflyfish or "False Falcula", C. ulietensis. Other fairly close relatives are the quite differently-shaped but similarly-colored Lined (C. lineolatus) and Spot-naped butterflyfishes (C. oxycephalus), while the Blue-cheeked Butterflyfish (C. semilarvatus) seems to be a far more basal lineage relative to all of these. The bluish vertical lines are present in all of these, while a white body with yellow behind and black on back and caudal peduncle are only shared among the four less ancient species