Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Acanthuridae
(Surgeonfishes, tangs, unicornfishes) > Acanthurinae
Etymology: Acanthurus: Greek, akantha = thorn + Greek, oura = tail (Ref. 45335). More on author: Shaw.
Environment: milieu / climate zone / depth range / distribution range
Marine; reef-associated; depth range 0 - 10 m (Ref. 27115), usually 0 - 4 m (Ref. 9710). Tropical; 28°N - 26°S, 143°E - 109°W
Western Pacific: oceanic islands of Oceania to the Hawaiian and Pitcairn islands. Also known from Wake, Marcus, and Mariana islands. Eastern Central Pacific: southern tip of Baja California, Mexico (Ref. 9267) and other offshore islands.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 24.0 cm TL male/unsexed; (Ref. 9710)
soft rays: 26 - 29. Dark brown, nearly black in color. Erectile spine (sharp and forward-pointing) on each side of caudal peduncle which folds down into a groove. Mouth small, snout noticeably extended. Light blue ring around chin and presence of spot of same color on gill cover at angle of gill opening. Dorsal fin with soft part having longer base than spinous part. Juveniles lack the large orange spot on caudal area.
Occurs in clear seaward reefs, usually in groups (Ref. 9710). Benthopelagic (Ref. 58302). Feeds on filamentous and small fleshy algae (Ref. 9267). Monogamous (Ref. 52884). Spine in caudal peduncle may be venomous. Size of metamorphosis from postlarva stage to juvenile is 6 cm (Ref. 9267). This species sometimes hybridizes with A. nigricans (Ref. 9808).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Monogamous mating is observed as both facultative and social (Ref. 52884).
Randall, J.E., 1956. A revision of the surgeonfish genus Acanthurus. Pac. Sci. 10(2):159-235. (Ref. 1920)
IUCN Red List Status (Ref. 119314)
CITES (Ref. 115941)
Threat to humans
Traumatogenic (Ref. 4690)
Fisheries: commercial; aquarium: commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Preferred temperature (Ref. 115969
): 25.8 - 28.3, mean 27.4 (based on 404 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00813 (0.00462 - 0.01429), b=2.87 (2.72 - 3.02), 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.
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low vulnerability (24 of 100) .