Eptatretus grouseri


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Eptatretus grouseri
Species Authority: McMillan, 1999

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2013
Date Assessed: 2009-11-10
Assessor(s): Mincarone, M.M.
Reviewer(s): Polidoro, B., Knapp, L. & Carpenter, K.E.
This species is known only by four museum specimens and is likely endemic to the Galapagos Archipelago. It is probably a deepwater species as specimens were recorded between 648 and 722 m. There are no known threats likely to affect this species, given its deep water habitat. It is also found entirely within the Galapagos Marine Protected Area. It is therefore listed as Least Concern. However, more research is needed on this species' population, biology, life history, and potential threats.

Geographic Range [top]

Range Description: This species is known only from two locations in Galápagos Archipelago: Fernandina Island and Seymour Island (McMillan 1999, Mincarone and McCosker 2004).
Ecuador (Galápagos)
FAO Marine Fishing Areas:
Pacific – southeast
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This species is known only from four museum specimens, but is very likely endemic to Galápagos Archipelago.
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: This species is found on the steep, sediment-laden slopes at depths from 648-722 m (Mincarone and McCosker 2004). The 378 mm holotype has tiny round eggs less than one mm in diameter with no ellipsoidal developing eggs and no tissue indicating previous large eggs (McMillan 1999).

This is a deep water insular species. The copulatory organ is absent in this species. 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 (Patzner 1998).
Systems: Marine

Threats [top]

Major Threat(s): There are no known direct threats to the species.

Conservation Actions [top]

Conservation Actions: This species is found within Galápagos Marine Reserve so it is potentially safeguarded through enforcement activities. More research is needed on this species' biology, population size, and distribution.

Bibliography [top]

IUCN. 2011. IUCN Red List of Threatened Species (ver. 2011.1). Available at: (Accessed: 16 June 2011).

McMillan, C.B. 1999. Three new species of hagfish (Myxinidae, Eptatretus) from the Galápagos Islands. Fisheries Bulletin 97(1): 110-117.

Mincarone, M.M. and McCosker, J.E. 2004. Eptatretus lakeside sp. nov., a new species of five-gilled hagfish (Myxinidae) from the Galápagos Islands. Proceedings of the California Academy of Science 55(6): 162-168.

Patzner, R.A. 1998. Gonads and reproduction in hagfishes. In: J.M. Jørgensen, J.P. Lomholt, R.E. Weber, and H. Malte (eds), The biology of hagfishes, pp. 378-395. Chapman & Hall, London.

Citation: Mincarone, M.M. 2013. Eptatretus grouseri. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 27 March 2015.
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