Actinopteri (ray-finned fishes) > Scombriformes
(Mackerels) > Gempylidae
Etymology: Rexea: Latin, rex, rego = king.
Environment: milieu / climate zone / depth range / distribution range
Marine; benthopelagic; depth range 340 - 370 m (Ref. 6181). Deep-water; 34°N - 18°S, 53°E - 154°W (Ref. 6181)
Indo-West Pacific: Nazareth Bank and off Sumatra in the Indian Ocean and Kyushu-Palau Ridge, Japan and off Oahu, Hawaii.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 38.0 cm SL male/unsexed; (Ref. 6181)
(total): 19 - 20;
soft rays: 12 - 13;
Vertebrae: 34. Pectoral fin is represented by a single spine in small specimens or entirely absent in individuals over 25 cm SL. Lateral line branching below the 5th to 6th spine of the first dorsal fin. The upper line reaches to the base of the first dorsal finlet, the lower line runs sub laterally. Most of the body is naked except for a large rectangular stripe of squamation extending forward from the caudal peduncle. Overall color is grayish brown; a black blotch is on membranes between the first and third dorsal-fin spine.
Mesobenthopelagic (Ref. 58302). Matures at about 25 cm standard length (Ref. 6181).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Nakamura, I. and N.V. Parin, 1993. FAO Species Catalogue. Vol. 15. Snake mackerels and cutlassfishes of the world (families Gempylidae and Trichiuridae). An annotated and illustrated catalogue of the snake mackerels, snoeks, escolars, gemfishes, sackfishes, domine, oilfish, cutlassfishes,. scabbardfishes, hairtails, and frostfishes known to date. FAO Fish. Synop. 125(15):136 p. (Ref. 6181)
IUCN Red List Status (Ref. 125652)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Preferred temperature (Ref. 123201
): 3.9 - 7.2, mean 6 °C (based on 147 cells).
Phylogenetic diversity index (Ref. 82804
= 0.5078 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00372 (0.00166 - 0.00830), b=3.10 (2.91 - 3.29), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 4.2 ±0.7 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153
): Moderate vulnerability (36 of 100).