Chaetodon xanthocephalus is one of the 88 members belonging to the genus Chaetodon, which together with 11 additional genera make up the butterflyfishes family (Chaetodontidae) in which there are currently a total of 129 described species. It is a species that inhabits the waters of the western Indian Ocean, especially on the east coast of Africa and Madagascar, although it is also present at the other extreme, for example in the Maldives. Generally, we find this species in waters between the surface and 20 meters deep, in habitats such as lagoons and coral reefs.
With an oval body, and laterally compressed, the rostrum of Chaetodon xanthocephalus is elongated and at its anterior end we find a small mouth oriented slightly upwards. The dorsal cephalic profile is strongly convex, while the ventral profile is concave. They can grow to a maximum total length of 20 cm. The dorsal fin has 13-14 spines and 21-26 soft rays, the anal has 3 spines and 21-23 rays and the caudal fin is truncated in shape.
The livery of Chaetodon xanthocephalus is formed by a pearly white background color with golden yellow rostral region, which expands thinly bordering the dorsal and ventral edges, completely covering the dorsal and anal fins. In the central part of the body we find a thin stripes oriented more or less vertically and are grayish blue. Just below the eyes, there is a thin blue stripe that runs in the direction of the mouth. There is also a golden yellowish stripe just behind the operculum. The rear portions of the dorsal and anal fins have thin blue stripes with the outer edges of the fins in yellow. The caudal fin is grayish with yellow outer margins.
Chaetodon xanthocephalus is a species that we will either find solitary or forming small groups of no more than 5-6 individuals. It is a territorial species and quite aggressive towards other species of the same genus. During the reproductive season, pairs are formed that will release eggs and sperm into the water column, so that fertilization occurs and the dominant currents spread their small eggs over a vast territory. Approximately 30 hours after fertilization, the fry will hatch and live for a long period pelagically.Photos: