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 180 - m (Ref. 31276), usually - m (Ref. ). Deep-water; 0°C -
Northwest Pacific: southwest of Taiwan (northern South China Sea).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 37.7 cm TL male/unsexed; (Ref. 31276)
Morphology | Morphometrics
5 pairs gill pouches and gill apertures, closely spaced in a straight line; branchial slime pores absent; fused unicuspid teeth 3/3; dental formula: 10 + 3/3 + 10; no whitish mid-dorsal stripe.
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
Preferred temperature (Ref. 115969
): 2.8 - 6.4, mean 4.2 °C (based on 63 cells).
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
): 4.2 ±0.5 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (Fec assumed to be <100).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (30 of 100) .