Myxine ios 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Myxini Myxiniformes Myxinidae

Scientific Name: Myxine ios
Species Authority: Fernholm, 1981
Regional Assessments:
Common Name(s):
English White-headed Hagfish
French Myxine à Tête Blanche
Taxonomic Notes: According to Møller et al. (2005), some records of M. ios from the Denmark Strait (Fernholm and Vladykov 1984, Jónsson 1992) and West Greenland (Jørgensen 2003) might belong to M. jespersenae.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2013
Date Assessed: 2009-11-12
Assessor(s): Mincarone, M.M.
Reviewer(s): Polidoro, B., Knapp, L. & Carpenter, K.E.
This species is only known from a few deep water specimens off the coast of Ireland, West Africa, and Angola. There are no known threats to this species. However, it may be caught in bottom trawling fisheries within its range. It is listed as Least Concern. More research is needed on this species distribution, population, biology, life history, and potential threats, especially as this species has an unknown distribution and is potentially susceptible to deep-sea trawling along the continental slope. There are questions regarding whether the Irish population is the same species as the African population.

Geographic Range [top]

Range Description: This species is known from two populations as defined by Fernholm (1981). The Irish population is mainly known from Porcupine Seabight, southwestern Ireland. The West African population is known off Western Sahara, from Cap Boujdour to Cap Blanc. Two specimens were recently trawled off Angolan waters and they present the same characters as those from Western Sahara (Tweddle and Anderson 2008, Mincarone unpublished data).
Countries occurrence:
Angola (Angola); Ireland; Western Sahara
FAO Marine Fishing Areas:
Atlantic – northeast; Atlantic – southeast; Atlantic – eastern central
Lower depth limit (metres): 1625
Upper depth limit (metres): 614
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This population is only know from a few museum specimens collected from locations along the Eastern Atlantic from Ireland and the coast of Angola.
Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: The Irish specimens were caught in semi-balloon otter trawls on the Porcupine Seabight, an amphitheatre-shaped embayment in the continental margin to the southwest of Ireland, at depths from 985-1,650 m (Merrett et al. 1991, Massutí et al. 2004). The bottom water temperatures from two Irish capture localities were 4.7°C and 6.2-6.4°C, and the associated fauna and collection data suggest that the bottom substrate was soft mud. A list of 118 species of fishes taken from Porcupine Seabight (including M. ios) was provided by Merrett et al. (1991).

The West African specimens were collected in baited traps on the lower slope at depths from 614-976 m (Fernholm 1981). Angolan specimens were trawled on the lower slope at depths from 703-734m.

All the West African material was caught in March and contains no ripe individuals (largest maturing eggs found are 5-9 mm) and the Irish material contains a recently spawned female captured in July and males appearing ripe in June and July (Fernholm 1981).

This species consists of scavengers which are found on muddy bottoms and feed largely on dead or disabled fish by boring into its skin. Its eggs are few and large (20-30 mm). 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 this species but its currently known distribution range overlaps with areas where deep-sea trawling occurs (Ireland and West Africa).

Conservation Actions [top]

Conservation Actions: There are no conservation measures in place, but more research is needed on this species' biology, population size, distribution and impact of deep-sea trawling activities.

Citation: Mincarone, M.M. 2013. Myxine ios. The IUCN Red List of Threatened Species 2013: e.T196060A8989969. . Downloaded on 28 November 2015.
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