Latin name

Acanthurus achilles

Other name

Redtail surgeonfish or redspot surgeonfish.

Identification

The Achilles tang has an elongated, oval body with a steep dorsal head profile. The small, forward-protruding mouth is located low on the head, with 8 to 28 teeth fixed on each jaw, each tooth having a flattened, serrated tip. On each side of the caudal peduncle there is one movable spine that folds into a groove.

Features of fish fins

The dorsal fin is supported by 9 spines and 29 to 33 soft rays, while the anal fin contains 3 spines and 26 to 29 soft rays. The caudal fin is concave.

Fish coloring

A black fish with bright orange and white lining along the fins and tail. As the fish matures, a bright orange teardrop-shaped mark with a pointed, rear-facing tip appears on the caudal area. There is a pale blue ring around the tip of the snout.

Distribution

They are found in the Western Pacific Ocean: from the islands of Oceania to the Hawaiian Islands and Pitcairn Island. Also known from Wake, Marcus, and the Mariana Islands. In the Eastern Central Pacific Ocean: the southern tip of Baja California, Mexico, and other coastal islands.

Habitat

A tropical Pacific marine fish associated with reefs. Its depth range is 0–10 meters (0–33 feet), typically 0–4 meters (0–13 feet).

Size

The maximum total length of this species reaches 24 cm (9.4 inches).

Behavior

Adults inhabit exposed seaward reefs, usually in groups. They are non-migratory.

Food and feeding habits

A herbivorous species. The fish primarily eat benthic algae.

Reproduction

Monogamous. The size of metamorphosis from post-larval stage to juvenile is 6 cm (2.4 inches). This species sometimes hybridizes with A. nigricans.

Fishing

This fish species is sometimes used in the aquarium trade, but is not a widely commercialized species. Their capture requires observing certain safety precautions.

Relationship with a person

Traumatogenic. The spine on the caudal peduncle can be venomous. They are rarely seen in the trade, and keeping them in an aquarium is recommended only for experienced aquarists.