Acanthurus olivaceus

Orange-blotch surgeonfish | Gendarme Fish | Olive Surgeonfish | Orange-epaulette Surgeonfish | Orangeband Surgeonfish | Orangebar Surgeonfish | Orangespot Surgeonfish | Orangespot Tang
Acanthurus olivaceus
Acanthurus olivaceus, adult, NSW, Australia, Photo: Ian Shaw
Acanthurus olivaceus
Acanthurus olivaceus, juvenile, NSW, Australia, Photo: Ian Shaw
Acanthurus olivaceus
Acanthurus olivaceus, adult, Dark phase, Bali, Indonesia, Photo: Ian Shaw
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Acanthurus olivaceus
Acanthurus olivaceus
Acanthurus olivaceus


Temperate Australasia, Tropical Indo-Pacific


Oval-shaped body with a rounded head. Pale grey front half of body, dark rear half, broad black-edged orange streak behind eye, black tail spine, and lunate tail. Juveniles yellow, with a faint trace of an orange streak behind eye. Similar to other yellow juvenile surgeons and best distinguished by presence of adults.


Max Size: 35 cm

Sea Temperature Range: 17.4-31.3°C

Depth: 3-46m

Habitat Generalization Index: 18.82

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: Frequent (12.3% 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: Several (5 per transect)

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

Edit by: Joe Shields