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| == Description == | == Description == | ||
| The fish has a large mouth with a protruding lower jaw and a high and pointed ]. It is generally silver in color with green, blue or brown |
The fish has a large mouth with a protruding lower jaw and a high and pointed ]. 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 from {{convert|14|to|25|kg|lb}} | ||
| The fish eat ] for their first year of life and then become ]s of smaller fish. They live in ]s and ]s and in the ] at the outlets of rivers into the ocean, and may ] {{convert|1500|km|mi}} to spawn. | The fish eat ] for their first year of life and then become ]s of smaller fish. They live in ]s and ]s and in the ] at the outlets of rivers into the ocean, and may ] {{convert|1500|km|mi}} to spawn. | ||
Revision as of 23:27, 14 January 2011
| Inconnu | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Salmoniformes |
| Family: | Salmonidae |
| Subfamily: | Coregoninae |
| Genus: | Stenodus Richardson, 1836 |
| Species: | S. leucichthys |
| Binomial name | |
| Stenodus leucichthys (Güldenstädt, 1772) | |
The inconnu (Stenodus leucichthys) is a species of freshwater whitefish of the family Salmonidae. It is also known as the "coney", nelma, belorybitsa, or sheefish. It is the only species in the genus Stenodus.
Description
The fish has a large mouth with a protruding lower jaw and a high and pointed dorsal fin. 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 from 14 to 25 kilograms (31 to 55 lb)
The fish eat plankton for their first year of life and then become predators of smaller fish. They live in lakes and rivers and in the brackish water at the outlets of rivers into the ocean, and may migrate 1,500 kilometres (930 mi) to spawn.
Distribution and habitat
It is found in north-bound drainages of North America and Eurasia, but a distinct stock also inhabits rivers draining to the Caspian Sea. The countries where it is native are Canada, China, Kazakhstan, Mongolia, Russia, and the United States.
Taxonomy
The species Stenodus leucichthys can be divided into two geographical subspecies. These subspecies are sometimes considered separate species, a treatment followed by the IUCN Red List., whereas others make no distinction.
- Stenodus leucichthys leucichthys (Güldenstädt, 1772), the nominate subspecies, is found only in rivers draining to the Caspian Sea, such as Volga in particular. This subspecies is now extinct in the wild.
- Stenodus leucichthys nelma (Pallas, 1773), is found in rivers draining to the Arctic basin, in Europe, northern Asia and North America.
Conservation
Fish of the nominate subspecies used to inhabit particularly the Volga, Ural and Terek rivers, and migrate up to 3,000 kilometres (1,900 mi) upstream from the Caspian to their spawning grounds in the spring. Following the construction of dams and hydropower reservoirs, the migration and natural reproduction has been impeded, and the taxon is now considered as extinct in the wild by the IUCN. The stock however survives in hatcheries and some populations are maintained by stocking, e.g. in the Caspian Sea.
References
- ^ Froese, Rainer; Pauly, Daniel (eds.). "Stenodus leucichthys". FishBase. February 2010 version.
- E. S. Belyaeva: Stenodus leucichthys leucichthys. caspianenvironment.org
- Template:IUCN
- ^ Template:IUCN
- "Stenodus leucichthys". Integrated Taxonomic Information System. Retrieved July 15, 2007.