Species encyclopedia

Pearlscale butterflyfish

Chaetodon xanthurus

Distribution area

Group

Size

Conservation status

Do you like this species ?

In the western Pacific, from Indonesia and the Philippines to southern Japan

Vertebrates
Ray-finned fishes

Up to 15cm

Least Concern

Biology

The pearlscale butterflyfish frequents coastal and outer reef slopes as well as drop-offs, where it is most often found at depths of over 15 metres. It is particularly fond of branching coral areas, such as Acropora, among which it finds food and shelter. Living alone or in pairs, it feeds on small invertebrates picked from the seabed and supplements its diet by grazing on algae.

It is easy to tell apart from its relatives: it is the only butterflyfish whose white, pearly flanks are covered in a fine dark crisscross pattern resembling the mesh of a net, hence its name. A broad orange band runs across the rear of the body and the caudal fin, while a black band masks its eye.

Reproduction

Knowledge of the pearlscale butterflyfish’s reproduction remains limited. It is known to form pairs to breed, and these pairs are thought to be long-lasting, as in many butterflyfish. It is also believed to spawn in open water, like most species in its family: at dusk, the male and female rise above the reef to release their reproductive cells simultaneously.

The eggs, transparent and buoyant, drift with the currents. They hatch into larvae known as “tholichthys”, unique to the butterflyfish family, whose heads are protected by bony plates. After several weeks of pelagic life, they settle on the reef, where they complete their development.

Did you know?
The pearlscale butterflyfish belongs to a group of almost identical butterflyfish that share the reefs of the Indo-Pacific: each lives in its own region, from the Red Sea to the Pacific. Among them, it is the only one to display this net pattern, whereas its relatives bear chevrons.

Pour poursuivre votre découverte du monde marin :