Actinopteri (ray-finned fishes) > Scombriformes
(Mackerels) > Gempylidae
Etymology: Rexichthys: Latin, rex, rego = king + Greek, ichthys = fish; johnpaxtoni: Named in honor of John R. Paxton, curator of the collection of fishes of the Australian Museum in Sydney (Ref. 44066).
Environment: milieu / climate zone / depth range / distribution range
Marine; benthopelagic; depth range 270 - 470 m (Ref. 9784). Deep-water; 17°S - 35°S, 140°E - 170°W (Ref. 6181)
Western Pacific: eastern coast of Australia between 17°31'S and 32°34'S, and from New Caledonia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 22.0 cm SL male/unsexed; (Ref. 6181)
soft rays: 12 - 13;
Vertebrae: 34. Body moderately elongate and compressed. Two lateral lines, the lower originating below the 6th to the 7th spine of the first dorsal fin, descending sharply to ventral contour of body, dividing into a short anterior branch and a much longer posterior branch. The pelvic fin represented by 1 spine and 2 tiny soft rays in smaller specimens but entirely absent in specimens over 10 cm SL. Body color is brownish, fins hyaline; first dorsal fin with a black blotch distally on two anterior membranes.
Adults are probably benthopelagic from 400 to 470 m while juveniles are pelagic from 270 to 400 m depth.
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
): 13.8 - 17.6, mean 17.2 °C (based on 13 cells).
Phylogenetic diversity index (Ref. 82804
= 1.0000 [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
): 3.8 ±0.5 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (Assuming tmax>3).
Fishing Vulnerability (Ref. 59153
): Low vulnerability (17 of 100).