Acanthurus achilles

Achilles tang
Acanthurus achilles
Acanthurus achilles, adult, French Polynesia, Photo: Antonia Cooper
Acanthurus achilles
Acanthurus achilles, French Polynesia, Photo: Graham Edgar
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Acanthurus achilles
Acanthurus achilles


Tropical Indo-Pacific


Very dark brown to almost black in colour. Has bright highlights of white and orange around the dorsal, caudal and anal fins, with a large orange teardrop marking at the rear of the body, extending into the caudal peduncle. This teardrop marking is displayed as a streak (or even absent) in juveniles.


Max Size: 24 cm

Sea Temperature Range: 24.1-30°C

Depth: 0-18 m

Habitat Generalization Index: 11.38

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.

Conservation and Rarity

IUCN Status: Least Concern

Occurrence: Infrequent (9.7% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Many (10 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.

Edit by: Antonia Cooper