Actinopteri (ray-finned fishes) > Gadiformes
(Cods) > Macrouridae
(Grenadiers or rattails)
Etymology: Hymenocephalus: Named for its transparent membrane-like head covering (‘‘hymen head’’) and fragile nature of head bones (Ref. 100825).
Environment: milieu / climate zone / depth range / distribution range
Marine; benthopelagic; depth range 570 - 1060 m (Ref. 28494). Deep-water
Northwest Pacific: off Hachijojima, Japan (Ref. 559); northern part of Bonin Ridge, on Miluoki and Nintoku Ridges and on Kyushu-Palau Ridge (Ref. 28494).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 20.0 cm TL male/unsexed; (Ref. 559)
Morphology | Morphometrics
This species is distinguished by the following characters: pelvic fin rays 7-8; pectoral fin rays 14-15; short, barely projecting snout, 15-17% HL; long barbel, 30-35% HL, reaching vertical through center of orbit; large orbit diameter, 35-38% HL; infraorbital width 10-12% HL; moderately long preopercular supporter, with straight rear margin, 6-7% HL; 18-20 gill rakers; ventral striae reaching to ½ distance from pelvic fin bases to periproct; otolith has high predorsal lobe, with colliculi separated, closely placed across collum; otolith length to height (OL:OH), 1.05; total colliculum length to pseudocolliculum length (TCL:PCL), 1.6 (Ref. 98298).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Masuda, H., K. Amaoka, C. Araga, T. Uyeno and T. Yoshino, 1984. The fishes of the Japanese Archipelago. Vol. 1. Tokai University Press, Tokyo, Japan. 437 p. (text). (Ref. 559)
IUCN Red List Status (Ref. 125652)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00209 (0.00104 - 0.00421), b=3.19 (3.02 - 3.36), in cm total length, based on LWR estimates for this Subfamily-BS (Ref. 93245
Trophic level (Ref. 69278
): 3.4 ±0.4 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
): Low vulnerability (10 of 100) .
Climate Vulnerability (Ref. 125649
): (0 of 100) .