Myxini (hagfishes) > Myxiniformes
(Hagfishes) > Myxinidae
(Hagfishes) > Eptatretinae
Etymology: Eptatretus: hepta (Gr.), seven; tretos (Gr.), perforated (i.e., with holes), referring to seven gill apertures on what would later be described as Homea banksii (=E. cirrhatus) [range within genus is 6-14 pairs of gill apertures]. (See ETYFish); mccoskeri: In honor of American ichthyologist John E. McCosker (b. 1945), California Academy of Sciences, for collecting holotype and for his important contributions to marine biology. (See ETYFish).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathydemersal; non-migratory; depth range 155 - 215 m (Ref. 31788). Deep-water
Southeast Pacific: Galapagos Islands.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 32.0 cm TL male/unsexed; (Ref. 31788)
Morphology | Morphometrics
This species is distinguished from its congeners, except Eptatretus poicilus by the following characters: gill apertures 8 pairs (7 in one specimen), well-spaced and arranged in a near straight line; a 3/3 multicusp pattern of teeth; differs from Eptatretus poicilus by its number of trunk pores 38-43 (vs. 45-50), by the number of total pores 69-75 (vs. 78-86) and by its colour pattern, with body purple to purplish brown (vs. body strongly mottled with pale brown, dark brown and white-beige) (Ref. 123790).
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 ).
McMillan, C.B., 1999. Three new species of hagfish (Myxinidae, Eptatretus) from the Galápagos Islands. Fish. Bull. 97:110-117. (Ref. 31788)
IUCN Red List Status (Ref. 125652)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 8.2 - 14.7, mean 9.6 °C (based on 7 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00200 (0.00093 - 0.00430), b=2.93 (2.74 - 3.12), in cm total length, based on LWR estimates for this Subfamily-BS (Ref. 93245
Trophic level (Ref. 69278
): 4.1 ±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).
Fishing Vulnerability (Ref. 59153
): Low vulnerability (22 of 100) .
Climate Vulnerability (Ref. 125649
): (0 of 100) .