Myxini (hagfishes) > Myxiniformes
(Hagfishes) > Myxinidae
(Hagfishes) > Eptatretinae
Etymology: Eptatretus: Greek, epta = seven + Greek, tretos, -e, -on = with holes (Ref. 45335); deani: Named after Bashford Dean, US ichthyologist and bibliographer (Ref. 6885).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathydemersal; non-migratory; depth range 103 - 2743 m (Ref. 31276). Deep-water; 60°N - 27°N, 148°W - 114°W
Eastern Pacific: southeastern Alaska to central Baja California, Mexico.
Length at first maturity / Size / Weight / Age
Maturity: Lm 38.0  range ? - ? cm
Max length : 63.5 cm TL male/unsexed; (Ref. 96339)
soft rays: 0. No true fins - one dorsal finfold, far back, median, very low, continuous with the caudal; caudal moderately broad, and round with ray-like markings; ventral finfold very low, origin somewhat posterior to last gill aperture, extending to anus (Ref. 6885). Prune colored, preserved specimens black; frequently piebald with light spots; the very edges of caudal and ventral finfolds may be light colored (Ref. 6885).
Inhabits mud bottoms (Ref. 2850). Minimum depth reported at 103 m (Ref. 80811).
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 ). In one study (Ref. 40710), hermaphroditism is exhibited by only 0.2% of the individuals examined.
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. 115185)
CITES (Ref. 115941)
Threat to humans
Fisheries: of no interest
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Preferred temperature (Ref. 115969
): 3.2 - 5.5, mean 4.3 (based on 54 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00229 (0.00135 - 0.00388), b=2.93 (2.78 - 3.08), in cm Total Length, based on LWR estimates for this species & (Sub)family-body (Ref. 93245
Trophic Level (Ref. 69278
): 3.8 ±0.52 se; Based on food items.
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (Fec = 14).
Vulnerability (Ref. 59153
): Moderate to high vulnerability (48 of 100) .