Teleostei (teleosts) > Stomiiformes
(Lightfishes and dragonfishes) > Stomiidae
(Barbeled dragonfishes) > Melanostomiinae
Etymology: Pachystomias: Greek, pachys = fat + Greek, stoma = mouth (Ref. 45335).
More on author: Günther.
Environment: milieu / climate zone / depth range / distribution range
Marine; bathypelagic; depth range 660 - 4000 m (Ref. 74511). Deep-water; 50°N - 37°S, 65°W - 154°W
Eastern Atlantic: scattered records from 50°N-31°N, then between 16°N-18°S and from 28°S-37°S but not taken close to the continent south of the equator. Western Atlantic: scattered records from 40°N-13°N. Also known from the Indian and Pacific oceans. South China Sea (Ref.74511).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 22.1 cm SL male/unsexed; (Ref. 4468)
soft rays: 23 - 28. Body moderately elongated, slightly compressed. Snout shorter than eye. Jaws slender, gape slightly curved upward. Barbel slender, tapering without a bulb. Velvety dark brown to black (Ref. 37473).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Gibbs, R.H. and M.A. Barnett, 1990. Melanostomiidae. p. 308-337. 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. 1. (Ref. 4468)
IUCN Red List Status (Ref. 126983)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Preferred temperature (Ref. 123201
): 2.3 - 5.4, mean 3.3 °C (based on 2272 cells).
Phylogenetic diversity index (Ref. 82804
= 1.0000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00302 (0.00117 - 0.00783), b=3.12 (2.89 - 3.35), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 4.2 ±0.73 se; based on food items.
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153
): Low vulnerability (17 of 100).