Eptatretus nanii


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Eptatretus nanii
Species Authority: Wisner & McMillan, 1988

Assessment Information [top]

Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2013
Date Assessed: 2009-11-13
Assessor(s): Mincarone, M.M.
Reviewer(s): Polidoro, B., Knapp, L. & Carpenter, K.E.
This species is only known from a few museum specimens off the coast of Chile, and has not been recorded since it was originally published in 1988. There are no current threats known to the species, but historically, intensive bottom trawling has occurring in at least some parts of its known range. It is listed as Data Deficient. More information is needed on this species distribution, population, biology, life history and impact of past trawling activities.

Geographic Range [top]

Range Description: This species is found off Chile, from about 28°S to 36°S (Wisner and McMillan 1988).
FAO Marine Fishing Areas:
Pacific – southeast
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The population for this species is only known from a few museum specimens. No records of this species have been published since the species was described in 1988.
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: This species is usually found on muddy bottoms on the outer shelf and upper slope at depths from 100-470 m. Six females (561-664 mm total length (TL)) examined by Wisner and McMillan (1988) had 22-38 well developed eggs, ranging in size from 16x3.5-27x6.5 mm. No eggs have protruding anchor filaments, although polar caps were well developed on many.

The copulatory organ is absent for 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 and bottom trawling activities along the continental slope have almost ceased, likely due to a collapse of the shallow water fisheries. While this species prefers deeper water it was likely vulnerable to historical bottom-trawling activities. Mid-water fishing continues but this is not a threat to this species (R. Melendez pers. comm. 2009). While the fishing threat has ceased, past activities may have significantly reduced the population through bycatch incidences and habitat destruction. It is slightly concerning that no specimens are currently being picked up in scientific surveys.

Conservation Actions [top]

Conservation Actions: There are no conservation measures in place, but more research is needed on species' biology, population size, distribution and the historical impact of bottom trawling activities along the continental shelf.

Bibliography [top]

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

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.

Wisner, R.L. and McMillan, C.B. 1988. A new species of hagfish, genus Eptatretus (Cyclostomata, Myxinidae), from the Pacific Ocean near Valparaiso, Chile, with new data on E. bischoffii and E. polytrema. Transactions of the San Diego Society of Natural History 21(14): 227-244.

Citation: Mincarone, M.M. 2013. Eptatretus nanii. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 28 August 2015.
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