Achilles Tang - Acanthurus achilles

Achilles Tang (Acanthurus achilles)

The Achilles Tang, Acanthurus achilles, is one of the most iconic and desirable marine surgeonfish, instantly recognised by its deep velvet-black body, bright orange teardrop marking near the tail, white facial highlights and striking orange caudal edging. It is an exceptionally active, powerful swimmer with a bold presence in the aquarium, making it a true centrepiece species for large mature reef systems. However, this is not a beginner tang. The Achilles Tang is demanding, oxygen-hungry and sensitive to poor water quality, making it best suited to experienced marine fishkeepers with large, stable, high-flow aquariums.

Common Name:
Achilles Tang, Achilles Surgeonfish, Redtail Surgeonfish, Orange Spot Surgeonfish.

Scientific Name (Latin):
Acanthurus achilles

Maximum Size:
Up to around 24 cm, making it a medium to large surgeonfish that requires excellent swimming space.

Water Type:
Marine

Origin / Natural Habitat:
Found across Pacific reef regions, especially oceanic islands of Oceania through to Hawaii and the Pitcairn Islands, with records also from Wake, Marcus and the Mariana Islands, as well as some eastern central Pacific offshore localities. In the wild, Achilles Tangs are associated with clear, high-energy seaward reefs, surge zones and well-oxygenated reef slopes. They are active grazers, spending much of the day moving across reef surfaces and feeding on filamentous and small fleshy algae.

Water Parameters:
Temperature: 24–27°C
pH Range: 8.1–8.4
Hardness or Salinity: SG 1.020–1.025

Temperament:
Semi-aggressive. Achilles Tangs can be territorial, especially towards other tangs, surgeonfish and similarly shaped algae grazers. They are best kept with robust, compatible marine fish in a large aquarium with enough space to establish territories. Avoid adding to cramped systems or housing with aggressive tangs that may outcompete or stress them.

Diet:
Primarily herbivorous grazer. In the wild, this species feeds heavily on filamentous algae and small fleshy algae growing across reef surfaces. In the aquarium, offer frequent feeds of marine algae sheets, nori, spirulina flakes, herbivore pellets, algae-based frozen foods and quality marine grazing foods. Small amounts of frozen mysis, enriched brineshrimp and finely chopped marine foods can also be offered, but the diet should remain strongly algae-focused. Regular feeding is important to maintain body condition and immune strength.

Minimum Tank Size:
A minimum of around 500 litres is recommended for a single specimen, with larger aquariums strongly preferred for long-term success. A long aquarium with open swimming space, strong flow, mature rockwork and high oxygen levels is far more suitable than a tall but cramped system.

Behaviour & Activity:
A very active daytime swimmer and constant grazer that needs room to move. Achilles Tangs are naturally associated with clear, turbulent reef areas, so they appreciate strong water movement, open swimming lanes and mature live rock for grazing. They can become stressed in low-flow, overcrowded or unstable aquariums. Like other surgeonfish, they have a sharp caudal peduncle spine near the tail, which can be used defensively. A secure lid is recommended, as startled marine fish can jump.

Reef Safe:
Reef Safe
Achilles Tangs are considered reef safe and do not normally nip corals or clam mantles. They are excellent algae grazers for suitable mature reef aquariums, but their adult size, swimming needs and sensitivity mean they should only be kept in larger, stable systems.

Special Requirements or Care Notes:
Best suited to experienced marine fishkeepers. This species needs excellent water quality, strong oxygenation, high flow, stable parameters and a large mature aquarium. Achilles Tangs are known to be more sensitive than many hardier tang species and can be prone to stress-related health issues if housed in unsuitable conditions. Quarantine, careful acclimation and a strong algae-based diet are highly recommended. Avoid keeping with aggressive tangs, very competitive feeders or in newly set up aquariums.

Suitable for:
Experienced fishkeepers

Availability:
Premium marine species / Availability can vary depending on collection, import, size and supplier

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.