Actinopteri (ray-finned fishes) > Eupercaria/misc
() > Scaridae
(Parrotfishes) > Scarinae
Etymology: Bolbometopon: Greek, bolbos-ou = onion + Greek, metopon = brow (Ref. 45335). More on author: Valenciennes.
Environment: milieu / climate zone / depth range / distribution range
Marine; reef-associated; depth range 1 - 40 m (Ref. 90102). Tropical; 34°N - 26°S, 32°E - 145°W (Ref. 116632)
Indo-Pacific: Red Sea and East Africa to Samoa and the Line Islands, north to the Yaeyama and Wake islands, south to the Great Barrier Reef and New Caledonia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 130 cm TL male/unsexed; (Ref. 9710); common length : 70.0 cm SL male/unsexed; (Ref. 9793); max. published weight: 46.0 kg (Ref. 2334)
soft rays: 9. This species is distinguished by the following characters: median predorsal scales 2-4 (may be obscured by hump); 3 scale rows on cheek, 1 (4-6), 2 (3-6), 3 (1-2); pectoral-fin rays 16 or 17; steep profile distinctive; nodules on teeth unique (Ref. 9793); prominent bump on forehead of adult (evident at least 25 cm TL); deep body 2.0-2.5 in SL, with depth increasing with growth; Colour of juveniles brownish to green with 5 vertical rows of whitish spots on side, the primary phase is a dull gray with scattered white spots, gradually becoming uniformly dark green (Ref. 90102, 1602).
Juveniles are found in lagoons while adults inhabit clear outer lagoon and seaward reefs up to depths of at least 30 m (Ref. 9710). They ‘sleep’ in caves and often in shipwrecks at night (Ref. 48636). They are usually in small groups feeding on benthic algae, live corals (Ref. 9710) and shellfishes (Ref. 58784). They sometimes ram their head against corals to facilitate feeding (Ref. 9710). The largest and wariest of the parrotfishes. Assessments showed their vulnerability to overfishing (Ref. 9710).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Oviparous, distinct pairing during breeding (Ref. 205). Also Ref. 103751.
Randall, J.E., G.R. Allen and R.C. Steene, 1990. Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press, Honolulu, Hawaii. 506 p. (Ref. 2334)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
Fisheries: commercial; aquarium: commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 25.3 - 29.1, mean 28.2 °C (based on 2570 cells).
Phylogenetic diversity index (Ref. 82805
= 1.0000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01445 (0.00668 - 0.03127), b=3.02 (2.84 - 3.20), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 2.7 ±0.41 se; based on food items.
Generation time: 11.0 ( na - na) years. Estimated as median ln(3)/K based on 2 growth studies.
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (K=0.10).
Vulnerability (Ref. 59153
): High to very high vulnerability (67 of 100) .