Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Acanthuridae
(Surgeonfishes, tangs, unicornfishes) > Acanthurinae
Etymology: Ctenochaetus: Greek, kteis, ktenos = comb + Greek, chaite = hair (Ref. 45335).
Environment / Climate / Range
Marine; reef-associated; depth range 1 - 35 m (Ref. 90102), usually 6 - 30 m (Ref. 58652). Tropical; 24°C - 28°C (Ref. 27115); 35°N - 30°S, 32°E - 130°W
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 26.0 cm TL male/unsexed; (Ref. 2334); common length : 18.0 cm TL male/unsexed; (Ref. 3146); max. reported age: 34 years (Ref. 93525)
soft rays: 24 - 28. Body dark olive-brown. Orange spots on head. Pectoral fin yellowish, caudal and ventral fins brown, anterior part of caudal fin pale. Each side of caudal peduncle with sharp, forward-pointing erectile spine which folds down into a horizontal groove. Scales minute. Juveniles with 8 - 12 pale stipes inclining downward and backwards on body. Teeth movable, slender, tips incurved and expanded; upper jaw 5-6 denticulations, lower only 3-4. Gill rakers 27-36 in anterior row, 29-42 in posterior row.
Indo-Pacific: throughout the region excluding the Hawaiian, Marquesas and Easter islands. Record from Baker Island (US Minor Islands) based on a photograph (Ref. 42056). Absent from Malden and Jarvis islands (Ref. 1602).
Inhabits reef flats and lagoon and seaward reefs to a depth of over 30 m. Occurs over coral (Ref. 58534), rock, pavement, or rubble substrates. May occur singly or in small to very large, often mixed-species aggregations (Ref. 48637). Feeds on surface film of blue-green algae and diatoms (making this species a key link in the ciguatera food chain) as well as on various small invertebrates.
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
In Tahiti, spawning starts near full moon with the formation of schools of several thousand fish at various depths. The fish remain almost motionless for between 1 to 3 hrs, then change their normal color to pale grey. About 4 or 5 fishes rise a few yards above main school & swim around each other discharging milt & eggs, then return to former place & replaced by another group to spawn.
Randall, J.E and K.D. Clements, 2001. Second revision of the surgeonfish genus Ctenochaetus (Perciformes: Acanthuridae), with descriptions of two new species. Indo-Pac. Fish. (32):33 p. (Ref. 42056)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Reports of ciguatera poisoning (Ref. 9513)
Fisheries: commercial; aquarium: commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5020 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.02239 (0.01813 - 0.02764), b=2.98 (2.92 - 3.04), based on LWR estimates for this species (Ref. 93245
Trophic Level (Ref. 69278
): 2.0 ±0.0 se; Based on diet studies.
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (Tmax = 34; K=0.87).
Vulnerability (Ref. 59153
): Low vulnerability (18 of 100) .