Acanthurus triostegus

Acanthurus triostegus and Labroides phthirophagus

The convict surgeonfish ( Acanthurus triostegus ), also grid - Doktorfisch called, is a species of the family Acanthuridae.

Distribution and habitat

The convict surgeonfish occurs throughout the tropical Indo-Pacific. It can be found on the coasts of East Africa as well as to those of Mexico and Panama. He lives there on the hard floors of outside reefs and in lagoons and can be observed in water depths from 0 to 90 meters.

Appearance

The convict surgeonfish, like all surgeonfish species a high-backed, laterally flattened body and reaches a body length of up to 26 cm. The fins edges of the anal and dorsal fins are rounded, the caudal fin is almost straight.

The body has a light gray to gray- white in color and has six vertical black gray stripes. A strip runs on the high-lying body eye; the last strip runs across the tail. At the beginning of the tail of the convict surgeonfish bears the typical scalpel surgeonfish mandrel.

Behavior

Convict surgeonfish form very often large flocks that can include up to 1,000 individuals. He also occasionally associated with other species such as rabbit and parrot fish. The formation of such feeding swarms is a behavioral adaptation due to the little nutritious staple diet of microalgae. In a swarm convict surgeonfish are able to penetrate into the feeding areas other fortified fish species. In 1998, corals were dying in large numbers from the Maldives, dissolved there the swarms of convict surgeonfish, since sufficient food reserves were available due to the algae volume.