''Stenodus nelma'', known alternatively as the nelma, sheefish, siifish, inconnu or connie, is a commercial species of

freshwater whitefish The freshwater whitefish are fishes of the subfamily Coregoninae, which contains whitefishes (both freshwater and anadromous) and ciscoes, and is one of three subfamilies in the salmon family Salmonidae. Apart from the subfamily Coregoninae, the ...

in the family

Salmonidae Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...

. It is widespread in the Arctic rivers from the

Kola Peninsula sjd, Куэлнэгк нёа̄ррк , image_name= Kola peninsula.png , image_caption= Kola Peninsula as a part of Murmansk Oblast , image_size= 300px , image_alt= , map_image= Murmansk in Russia.svg , map_caption = Location of Murmansk Oblas ...

(

White Sea The White Sea (russian: Белое море, ''Béloye móre''; Karelian and fi, Vienanmeri, lit. Dvina Sea; yrk, Сэрако ямʼ, ''Serako yam'') is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is su ...

basin) eastward across Siberia to the

Anadyr River The Anadyr (russian: Ана́дырь; Yukaghir: Онандырь; ckt, Йъаайваам) is a river in the far northeast of Siberia which flows into the Gulf of Anadyr of the Bering Sea and drains much of the interior of Chukotka Autonomous ...

and also in the North American basins of the

Yukon River The Yukon River (Gwichʼin language, Gwich'in: ''Ųųg Han'' or ''Yuk Han'', Central Alaskan Yup'ik language, Yup'ik: ''Kuigpak'', Inupiaq language, Inupiaq: ''Kuukpak'', Deg Xinag language, Deg Xinag: ''Yeqin'', Hän language, Hän: ''Tth'echù' ...

and Mackenzie River.Eschmeyer F
Catalog of Fishes
(Search: Stenodus (species)) California Academy of Sciences. (15 March 2012 version)

Appearance and lifestyle

''Stenodus nelma'' is an anadromous fish, up to in length. The fish has a large mouth with a protruding lower jaw and a high and pointed

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

. It is generally silver in color with a green, blue or brown back. The meat is white, flaky and somewhat oily. An adult fish weighs up to . The fish eat

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

for their first year of life and then become

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

s of smaller fish. They live in

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s and

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

s and in the

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estua ...

at the outlets of rivers into the ocean. They may migrate more than to their upriver spawning grounds, but some populations spend their entire life in fresh water and do not migrate.

Systematics

''Stenodus nelma'' has previously been considered a subspecies of ''

Stenodus leucichthys ''Stenodus leucichthys'' is a species of freshwater whitefish in the family Salmonidae. In the strict sense its natural distribution is restricted to the Caspian Sea basin, and it is known as beloribitsa (literally meaning "the fish that is whit ...

'' (''S. leucichthys nelma''). The typical ''Stenodus leucichthys'' (beloribitsa) is a landlocked Eurasian species restricted to the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

basin, and now

extinct in the wild A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as known only by living members kept in captivity or as a naturalized population outside its historic range due ...

Inuit fishing for sheefish at Selawik NWR

References

External links

"Mackenzie River Ecosystem: A Dynamic Delta: Inconnu: The "Unknown" Fish"
GreatCanadianRivers.com

Illustration by N.N. Kondrakov. NOAA Photo Library. Stenodus Freshwater fish of the Arctic Fish of the Arctic Ocean Fish described in 1773 Fish of Russia Fish of the United States {{Salmonidae-stub