Surgeonfishes and Relatives: Acanthuroidei

Physical characteristics: Lined surgeonfish have a disk-like body that is narrow from side to side. There is a large, venomous spine on each side of the tail. The tail fin is shaped like a crescent moon. The body color is yellowish green with bright blue stripes that are edged with black on the sides of the fish but not on the head. The belly is bluish white. The tail fin has two up-and-down lines of dark blue against a background of purplish gray. The pelvic fins, the pair that corresponds to the rear legs of four-footed animals, are bright orange. The other fins are purplish gray at the edges and greenish yellow at the base. The dorsal and anal fins are long. The dorsal (DOOR-suhl) fin is the one along the midline of the back. The anal (AY-nuhl) fin is the one along the midline of the belly. Lined surgeonfish grow to a length of about 15 inches (38 centimeters).

Geographic range: Lined surgeonfish live in the Indian and Pacific oceans.

Lined surgeonfish patrol their territory on reefs and aggressively attack other fishes, using their tail spines as weapons. (Illustration by Joseph E. Trumpey. Reproduced by permission.)

Habitat: Lined surgeonfish live on reefs at a depth of 3 to 10 feet (1 to 3 meters).

Diet: Lined surgeonfish eat algae.

Behavior and reproduction: Lined surgeonfish patrol their territory on reefs and aggressively attack other fishes, using their tail spines as weapons. Their head becomes a darker color during these meetings. Lined surgeonfish travel to spawn in groups at specific sites, although they sometimes spawn in pairs. Eggs and larvae float in open water. Lined surgeonfish live as long as forty-five years.

Lined surgeonfish and people: Lined surgeonfish are collected for aquariums and are caught and eaten by people who live near where the fish live.

Conservation status: Lined surgeonfish are not threatened or endangered. ∎