Semicircle Angelfish

Pomacanthus semicirculatus

Semicircle Angelfish (Pomacanthus semicirculatus) is a large Indo-Pacific reef angelfish, often seen singly or in pairs around coral slopes and lagoons. Juveniles look very different from adults, with bold blue-and-white rings that give the species its name.

Saltwater

Semicircle Angelfish reference image — Elias Levy, cc-by, via Wikimedia Commons. Source: Wikimedia Commons.

Identification points

Adult has a yellow to orange body with a strong dark vertical bar through the eye and a rounded tail.
Juvenile is dark blue-black with bright electric-blue concentric semicircles and rings on the body.
Long continuous dorsal and anal fins give it a tall, disc-like angelfish profile.

Habitat

Coral-rich reef slopes, lagoon patch reefs, seaward reef faces, and sheltered outer reef areas; juveniles often shelter among branching corals and rubble.

Bait notes

Not a targeted game fish; reef fish collectors and snorkelers observe it more than anglers pursue it. If incidentally hooked, small pieces of squid, clam, or reef-associated natural bait may attract it, but capture is uncommon and often discouraged.

Behavior

Primarily a benthic grazer that picks sponges, tunicates, algae, and other encrusting reef growth; adults are usually solitary or in pairs and are wary around divers and hooks.

Caution

Do not eat without local guidance: large reef fish can carry ciguatera risk in tropical areas. Check local rules before keeping or collecting, as reef angelfish may be protected or regulated in some jurisdictions.

Fishing notes

Best approached by snorkelers, photographers, or reef observers rather than anglers. In places where collection is regulated, avoid attempting to catch it; if encountered on light tackle, use very small natural baits near reef structure, but release immediately.