Actinopteri (ray-finned fishes) > Trachichthyiformes
(Roughies) > Diretmidae
Etymology: Diretmichthys: Greek, di = two + Greek, eretmos = oar + Greek, ichthys = fish (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathypelagic; depth range - 2100 m (Ref. 58018), usually - m (Ref. ). Deep-water; 0°C - ; 40°N - 40°S, 71°W - 154°W
Broadly distributed tropical and temperate species (Ref. 9927). Eastern Atlantic: off Morocco to Sierra Leone and from Angola to South Africa. Western Atlantic: Caribbean Sea (Ref. 6744); reported from Guianas (Ref. 13608). Western Indian Ocean: at about 38°S. Western Pacific: off Japan, China Sea, Arafura Sea (Ref. 9819), off Victoria, Australia (Ref. 6536) and New Zealand (Ref. 5755). Including west of Ireland, Flemish Cap, and Gulf of Maine (Moore, pers. comm.).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 40.0 cm TL male/unsexed; (Ref. 6622)
Juveniles found near the surface; adults mesopelagic below 500 m (Ref. 27121). May occur at depths greater than 2,000 m (Ref. 6536). Feed on small crustaceans and planktonic organisms (Ref. 27121). Breed all year round (Ref. 6744). Minimum depth range taken from Ref. 27000.
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Post, A., 1990. Diretmidae. p. 623-624. In J.C. Quero, J.C. Hureau, C. Karrer, A. Post and L. Saldanha (eds.) Check-list of the fishes of the eastern tropical Atlantic (CLOFETA). JNICT, Lisbon; SEI, Paris; and UNESCO, Paris. Vol. 2. (Ref. 6536)
IUCN Red List Status (Ref. 124695)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 4.5 - 13.9, mean 8.5 °C (based on 849 cells).
Phylogenetic diversity index (Ref. 82805
= 1.0625 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01549 (0.00732 - 0.03276), b=3.00 (2.81 - 3.19), in cm total length, based on LWR estimates for this species & (Sub)family-body (Ref. 93245
Trophic level (Ref. 69278
): 3.5 ±0.48 se; based on food items.
Vulnerability (Ref. 59153
): Low to moderate vulnerability (32 of 100) .