Myxini (hagfishes) > Myxiniformes
(Hagfishes) > Myxinidae
(Hagfishes) > Eptatretinae
Etymology: Eptatretus: Greek, epta = seven + Greek, tretos, -e, -on = with holes (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathydemersal; non-migratory; depth range 300 - 536 m (Ref. 31276), usually - m (Ref. ). Deep-water; 0°C -
Northwest Pacific: Japan. Notoriously confused with other unnamed species around Japan (Ref. 31276).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 61.0 cm TL male/unsexed; (Ref. 31276)
Morphology | Morphometrics
Gill pouches (GP) 6 pairs with gill apertures closely spaced in a fairly straight line; 1-2 GP at end of dental muscle. Ventral aorta splitting at about GP 5-6. Fused cusps 3/3. Total cusps 47-52. Prebranchial slime pores 12-19. Total pores 71-78. Eyespots faint or absent. Ventral finfold low to vestigial (Ref. 51420).
Attains over 50 cm TL (Ref. 559).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Copulatory organ absent. The gonads of hagfishes are situated in the peritoneal cavity. The ovary is found in the anterior portion of the gonad, and the testis is found in the posterior part. The animal becomes female if the cranial part of the gonad develops or male if the caudal part undergoes differentiation. If none develops, then the animal becomes sterile. If both anterior and posterior parts develop, then the animal becomes a functional hermaphrodite. However, hermaphroditism being characterised as functional needs to be validated by more reproduction studies (Ref. 51361 ).
Fernholm, B., 1998. Hagfish systematics. p. 33-44. In J.M. Jørgensen, J.P. Lomholt, R.E. Weber and H. Malte (eds.) The biology of hagfishes. Chapman & Hall, London. 578 p. (Ref. 31276)
IUCN Red List Status (Ref. 124695)
Threat to humans
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=0.00204 (0.00095 - 0.00438), b=2.92 (2.73 - 3.11), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 4.5 ±0.80 se; based on food items.
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (Fec assumed to be <100).
Vulnerability (Ref. 59153
): Moderate to high vulnerability (47 of 100) .