Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Lethrinidae
(Emperors or scavengers) > Monotaxinae
Etymology: Monotaxis: Greek, monos = one + Greek, taxis = disposition (Ref. 45335).
Environment / Climate / Range
Marine; reef-associated; non-migratory; depth range 1 - 100 m (Ref. 9710), usually 5 - 30 m (Ref. 9775). Tropical, preferred 28°C (Ref. 107945); 35°N - 30°S, 32°E - 130°W
Indo-Pacific: Red Sea and East Africa to the Hawaiian Islands and southeastern Oceania, north to Japan, south to Australia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 60.0 cm TL male/unsexed; (Ref. 2295); common length : 40.0 cm TL male/unsexed; (Ref. 2295); max. published weight: 5.9 kg (Ref. 40637)
soft rays: 9. The inner surface of the pectoral fin base is densely scaled. Body is generally bluish-gray grading to whitish on ventral parts; lips are yellow to pinkish. The area around the eye is often yellow or orange. Fins are generally without distinctive markings. The membranes are clear or dusky but often reddish to yellow-orange. The base of the upper pectoral fin rays and the inner base (i.e. the body side) of the pectoral axil are black. The caudal fin usually has blackish rays contrasted against the paler membranous part of the fin. Small juveniles (often also in large 20-30 cm individuals) whitish on lower half and with three prominent black saddles separated by narrower white bars on upper half. A vertical black bar crosses the eye from above.
Found in sand and rubble areas near coral reefs. Solitary fish are often encountered, but large adults usually form aggregations of up to about 50 individuals (Ref. 9710). Solitary or in groups (Ref. 90102). Benthopelagic (Ref. 58302). Nocturnal feeders (Ref. 9710). Feed mainly on gastropods, ophiuroids, and echinoids. Pagurids and brachyuran crabs, polychaetes, tunicates, and holothurians are consumed in lesser quantities. Marketed fresh (Ref. 9775). Ciguatoxic in Marshall Is. (Ref. 171).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Carpenter, K.E. and G.R. Allen, 1989. FAO Species Catalogue. Vol. 9. Emperor fishes and large-eye breams of the world (family Lethrinidae). An annotated and illustrated catalogue of lethrinid species known to date. FAO Fish. Synop. 125(9):118 p. Rome: FAO. (Ref. 2295)
IUCN Red List Status (Ref. 109396)
CITES (Ref. 94142)
Threat to humans
Reports of ciguatera poisoning (Ref. 4690)
Fisheries: commercial; gamefish: yes; aquarium: commercial
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 1.0000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01995 (0.01161 - 0.03429), b=2.98 (2.83 - 3.13), based on LWR estimates for this species & (Sub)family-body (Ref. 93245
Trophic Level (Ref. 69278
): 3.4 ±0.0 se; Based on diet studies.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Moderate vulnerability (42 of 100) .