Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Lethrinidae
(Emperors or scavengers) > Monotaxinae
Etymology: Gymnocranius: Greek, gymnos = naked + Greek, kranion = skull (Ref. 45335). More on authors: Temminck & Schlegel.
Environment: milieu / climate zone / depth range / distribution range
Marine; reef-associated; non-migratory; depth range 15 - 80 m (Ref. 2295). Tropical; 35°N - 9°S
Indo-West Pacific: southern Japan to the Indo-Malaysian region, probably eastward to India. Has often been confused w/ the young of Gymnocranius grandoculis, hence its distributional limits are somewhat obscure. Records of Gymnocranius griseus from the Western Indian Ocean probably pertain to Gymnocranius grandoculis.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 35.0 cm TL male/unsexed; (Ref. 2295); common length : 25.0 cm TL male/unsexed; (Ref. 2295)
In sheltered coastal bays and sand and mud slopes in depths over 20 m (Ref. 48635); also in coastal trawling grounds. Juveniles sometimes in shallow estuaries on algae reefs (Ref. 48635). Sometimes forms schools. Feeds on bottom-living invertebrates. Sexually mature upon reaching 15-17 cm SL. Sometimes caught with handlines and marketed dried (Ref. 9775) or fresh. In Hong Kong live fish markets (Ref. 27253).
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. 123251)
CITES (Ref. 118484)
Threat to humans
Fisheries: commercial; gamefish: yes
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
Estimates based on models
Preferred temperature (Ref. 115969
): 24.2 - 28.8, mean 28.1 °C (based on 445 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5010 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01778 (0.00754 - 0.04192), b=2.97 (2.78 - 3.16), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.2 ±0.44 se; based on food items.
Generation time: 5.0 ( na - na) years. Estimated as median ln(3)/K based on 1 growth studies.
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (K=0.22).
Vulnerability (Ref. 59153
): Moderate vulnerability (38 of 100) .