Actinopteri (ray-finned fishes) > Acanthuriformes
(Surgeonfishes) > Acanthuridae
(Surgeonfishes, tangs, unicornfishes) > Acanthurinae
Etymology: Acanthurus: Greek, akantha = thorn + Greek, oura = tail (Ref. 45335). More on author: Linnaeus.
Environment: milieu / climate zone / depth range / distribution range
Marine; reef-associated; depth range 1 - 67 m (Ref. 1602), usually 2 - 67 m (Ref. 27115). Tropical; 21°C - 29°C (Ref. 27115); 30°N - 24°S
Eastern Indian Ocean: known only from Cocos-Keeling Islands and Christmas Island. Pacific Ocean: Ryukyu Islands and Great Barrier Reef to the Hawaiian Islands and French Polynesia (excluding Rapa). This species has crossed the Eastern Pacific Barrier to the Revillagigedo Islands, Cocos Island, Galapagos Islands, and the coast of Mexico.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 21.3 cm TL male/unsexed; (Ref. 2334); max. reported age: 34 years (Ref. 52229)
soft rays: 26 - 28. A horizontally elongate white blotch directly below eye. No orange band in outer part of dorsal fin. Caudal peduncle black except for yellow edge of socket and sheath of peduncular spine. Base of pectoral fin black (ref 9808).Gill rakers on anterior row:17-19, on posterior row:18-20.
Adults inhabit hard substrate areas of clear lagoon and seaward reefs from the lower surge zone to at least 67 m and feeds on filamentous algae. Solitary or in groups (Ref. 90102). Monogamous (Ref. 52884, 48637). Benthopelagic (Ref. 58302). Small juveniles shy among large corals (Ref. 48637). Territorial species. Common throughout Micronesia and hybridizes with the rare A. achilles. Size of metamorphosis from the postlarva stage to juvenile is 5.5 to 6 cm (Ref. 9267).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Monogamous mating is observed as both facultative and social (Ref. 52884).
Myers, R.F., 1991. Micronesian reef fishes. Second Ed. Coral Graphics, Barrigada, Guam. 298 p. (Ref. 1602)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
Fisheries: subsistence fisheries; aquarium: commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 24.5 - 28.8, mean 27.4 °C (based on 650 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.02630 (0.01517 - 0.04562), b=2.93 (2.78 - 3.08), in cm total length, based on LWR estimates for this species & Genus-body shape (Ref. 93245
Trophic level (Ref. 69278
): 2.0 ±0.00 se; based on food items.
Generation time: 3.9 ( na - na) years. Estimated as median ln(3)/K based on 2 growth studies.
Resilience (Ref. 120179
): Very Low, minimum population doubling time more than 14 years (K=0.28; tmax=34).
Vulnerability (Ref. 59153
): Low vulnerability (20 of 100) .