Acanthurus nigroris

Bluelined surgeonfish
Acanthurus nigroris
Acanthurus nigroris, Coral Sea, Australia, Photo: Rick Stuart-Smith
Acanthurus nigroris
Acanthurus nigroris, Cook Islands, Photo: Graham Edgar
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Acanthurus nigroris
Acanthurus nigroris


Tropical Indo-Pacific


Brown body with dark spots at upper and lower tail base, pale lines on face and body, fins with blue margins and slightly concave head profile. Similar A. nigrofuscus (Dusky Surgeonfish) has spots on face rather than lines.


Max Size: 25 cm

Sea Temperature Range: 22.3-30.1°C

Depth: 1-90m

Habitat Generalization Index: 13.25

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 (12.5% 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 (26 per transect)

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

Edit by: Joe Shields