The Yellowhead Butterflyfish (Chaetodon xanthocephalus) is also known as the Goldheaded Butterflyfish and Goldring Butterflyfish. They are widely distributed but are not common in any part of their range.
The body of the Yellowhead Butterflyfish is a typical butterflyfish shape, laterally compressed and oval with a pointed nose. The main body color is white with six or seven thin purple vertical stripes down the main part of the body. As its name suggests it has a yellow face with yellow stripes extending up onto the dorsal area and down to the pelvic fin.
There is a short black bar through the eyes and a thin yellow line on the rear of the gill plate. The dorsal and anal fins are orange with light blackmarks on the lower rear and are edged in yellow. The caudal fin is light grey also edged in yellow. They have a pointed mouth with sharp, narrow teeth and grow to up to 20 cm. In the wild most seem to be 12 to 15cm. It is impossible to sex them from their looks.
YELLOWHEAD BUTTERFLYFISH IN THE WILD
The Yellowhead Butterflyfish are mainly seen on deeper reefs in Tanzania, often around isolated coral heads. They are usually seen in pairs but sometimes are seen singularly. On rare occasions small groups of five or six fish are seen. Small juveniles are seen singularly in the shallows on protected reefs often in turbulent areas and are very reclusive making them difficult to photograph. In Tanzania the adults are usually found on isolated coral rich coral heads with a fair amount of current from 12 meters downwards.
Yellowhead Butterflyfish are found only in the Indian Ocean from the East Coast of Africa to Sri Lanka including the Maldives and Myanmar and west coast of Thailand. They are found from 2 to 30 meters in depth but in Tanzanian waters adults are more common below 12 meters.
Yellowhead Butterflyfish are omnivores and feed on algae and coral polyps.
Little is known about the mating habits of the Yellowhead Butterflyfish. They are however often seen in pairs which may be monogamous. As with most Butterflyfish, the female swells with eggs and spawning takes place by scattering into the water table with the male fertilizing the eggs.
The eggs are spherical and buoyant and it is thought they hatch in 28 to 30 hours. Once the eggs hatch a bony plate forms over the head area and the larvae called tholichthys, are pelagic for quite some time. They slowly develop into juveniles. This phase makes it extremely difficult to breed butterflyfish in aquariums.
Where their range overlaps with the Saddled Butterflyfish (Chaetodon ephippium) hybrids are known in the wild.
Yellowhead Butterflyfish are sometimes kept in aquariums but due to their habit of picking on coral are not that commonly kept. Their potential size of up to 20cm requires a fairly large aquarium. They are not reef safe. They will likely nibble on mollusks and tubeworms.
YELLOWHEAD BUTTERFLYFISH CLASSIFICATION
Species: C. xanthocephalus
Allen, Gerald R. 1979. Butterfly and Angelfishes of the World. Vol. 2.
Burgess, Warren E. 1978. Butterflyfishes of the World; A Monograph of the Family Chaetodontidae. T.F.H. Publications, NJ.832 pp.
The Reef Guide: Southern Africa’s East and South Coasts
Dennis King and Valda Fraser
The butterflyfishes: success on the coral reef
edited by Philip J. Motta