Chaetodon falcula

Description

Chaetodon falcula, the blackwedged butterflyfish or falcula butterflyfish, 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 blackwedged 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.