|Scientific Name:||Myxine circifrons|
|Species Authority:||Garman, 1899|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer/s:||Polidoro, B., Knapp, L. & Carpenter, K.E.|
This species is widespread in the Eastern Pacific, and is considered common. Although there may be some deep-sea trawl fisheries operating within at least part of the depth and distributional range of this species, there is no current indication of widespread population decline. It is listed as Least Concern.
|Range Description:||This species is located in the eastern Pacific, from San Francisco (California, USA) to San Antonio (central Chile) (Wisner and McMillan 1995).|
Native:Chile; Colombia; Costa Rica; Ecuador; El Salvador; Guatemala; Mexico; Nicaragua; Panama; Peru; United States
|FAO Marine Fishing Areas:||
Pacific – eastern central; Pacific – southeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The population for this species is known from many specimens collected from Southern California, Gulf of California, Costa Rica and Chile. There are also numerous records housed in museums. This species is known to be common, particularly along the northern part of its range but this is likely a sampling bias as this part of the distribution range has been heavily surveyed. Records are unreported along the western coast of South America.|
|Habitat and Ecology:||
This species is found on the continental slopes at depths from 700-1,860 m (Wisner and McMillan 1995). The syntypes were collected in the Gulf of Panama at 1,334 m depth in water of 3.6°C on rocky bottom (Garman 1899). The sex ratio in the material analyzed by Wisner and McMillan (1995) was equal off southern California (n=220) but unequal near the mouth of the Gulf of California (n=136), 66% females and 34% males, and Costa Rica to northern Chile (n=54), 59% female to 41% male; no hermaphroditism was found in 320 specimens examined.
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).
|Major Threat(s):||There are no known direct threats to this species but it is exposed to deep-sea bottom trawling throughout its distribution range.|
|Conservation Actions:||Marine Protected Areas in Southern California, Gulf of California and along the coast of Central America protect only very small parts of the species' range (<10%). More research needed on species' biology, population size and impact of deep-sea fishery.|
Adam, H. and Strahan, R. 1963. Systematics and geographical distribution of myxinoids. In: A. Brodal and R. Fänge (eds), The biology of Myxine, pp. 588. Universitetsforlaget, Oslo.
Bigelow, H.B. and Schroeder, W.C. 1948. Cyclostomes. In: J. Tee-Van, C.M. Breder, S.F. Hildebrand, A.E. Parr and W.C. Schroeder (eds), Fishes of the western North Atlantic, pp. 29-58. Memoir. Sears Foundation for Marine Research.
Chirichigno, N.F. and J. Vélez D. 1998. Clave para identificar los peces marinos del Perú (Seguenda edición, revidada y actualizada). Instituto del Mar del Peru, Publicación especial.
Eschmeyer, W.N., Herald, E.S. and Hammann, H. 1983. A field guide to Pacific coast fishes of North America. Houghton Mifflin Company, Boston.
Garman, S. 1899. The fishes. Reports on an exploration off the west coasts of Mexico, Central and South America, and off the Galapagos Islands in charge of Alexander Agassiz, by the the U.S. Fish Commission steamer "Albatross", during 1891, Lieut. Commander Z. L. Tanner, U.S.N., commanding. XXVI, pp. 1-431. Memoirs of the Museum of Comparative Zoology.
Hendrickx, M.E. and Hastings, P.A. 2007. Ecological data for Myxine circifrons Garman 1899 (Myxiniformes Myxinidae) in the Gulf of California, Mexico. Hidrobiológica 17(3): 273-276.
Hubbs, C.L., Follett, W.I. and Dempster, L.J. 1979. List of the fishes of California. Occasional Papers of the California Academy of Sciences.
IUCN. 2011. IUCN Red List of Threatened Species (ver. 2011.1). Available at: http://www.iucnredlist.org. (Accessed: 16 June 2011).
Miller, D.J. and Lea, R.N. 1972. Guide to the coastal marine fishes of California. California Fish Bulletin 157: 1-235.
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.
Regan, C.T. 1913. A revision of the myxinoids of the genus Myxine. Annals and Magazine of Natural History 11(8): 395-398.
Rubio, E.A., Pedraza, M.J., Zapata, L.A. 2005. Primer hallazgo de Myxine circifrons Garman 1899 (Agnatha: Myxinidae) en la costa del Pacifico de Colombia. Gayana 69(1): 118-121.
Wisner, R.L. and McMillan, C.B. 1995. Review of new world hagfishes of the genus *Myxine* (Agnatha, Myxinidae) with descriptions of nine new species. Fisheries Bulletin 93(3): 530-550.
|Citation:||Mincarone, M.M. 2011. Myxine circifrons. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 25 May 2013.|
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