About Chaetodon semilarvatus Cuvier, 1831
The bluecheek butterflyfish, Chaetodon semilarvatus Cuvier, 1831, has a bright yellow body marked with thin vertical red lines. It has a greyish patch behind its eyes, while most closely related species have an eye bar instead. All of its dorsal, anal, pelvic and caudal fins are yellow. This is a relatively large butterflyfish species that can reach a maximum total length of 23 centimetres (9.1 in), though a length of 15 centimetres (5.9 in) is more typical. This species is found in the north-western Indian Ocean, specifically in the Red Sea and the Gulf of Aden, ranging as far east as the coast of Oman. Bluecheek butterflyfish are among the few fish species that form long-term mating pairs. In their natural habitat, they feed on hard corals and benthic invertebrates. They are a common species that inhabits areas with abundant coral growth, and are most often observed either in pairs or in small shoals. They have been recorded occasionally hovering stationary for long periods beneath ledges of plate corals belonging to the genus Acropora. This is an oviparous species that forms spawning pairs, and spawning normally takes place during the day. The species emerges and is active at night. It occurs at depths ranging from 1 to 20 metres (3.3 to 65.6 ft).
