''Coregonus fera'', commonly called the ''true fera'', is a presumed extinct

freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of s ...

from

Lake Geneva , image = Lake Geneva by Sentinel-2.jpg , caption = Satellite image , image_bathymetry = , caption_bathymetry = , location = Switzerland, France , coords = , lake_type = Glacial la ...

in Switzerland and

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...

Description

Coregonus fera Jurine 1825 Fig 115 (Matschie et al

The fera is a 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, ...

that reached a length between 35 and 40 centimetres. It is a member of the

common whitefish ''Coregonus lavaretus'' is a species of freshwater whitefish, in the family Salmonidae. It is the type species of its genus ''Coregonus''. There are widely different concepts about the delimitation of the species ''Coregonus lavaretus'' and abou ...

complex (''Coregonus lavaretus'' sensu lato). The identity of the fera is disputed. In 1950 Emile Dottrens described ''Coregonus fera'' as native to both

Lake Geneva , image = Lake Geneva by Sentinel-2.jpg , caption = Satellite image , image_bathymetry = , caption_bathymetry = , location = Switzerland, France , coords = , lake_type = Glacial la ...

and

Lake Constance Lake Constance (german: Bodensee, ) refers to three bodies of water on the Rhine at the northern foot of the Alps: Upper Lake Constance (''Obersee''), Lower Lake Constance (''Untersee''), and a connecting stretch of the Rhine, called the Lak ...

. The coregonines from Lake Constance were named ''Sandfelchen''. In 1997

Maurice Kottelat Maurice Kottelat (born 16 July 1957 in Delémont, Switzerland ...

made a revision and used the name ''Coregonus fera'' for the Geneva fera and ''

Coregonus arenicolus ''Coregonus arenicolus'' is a freshwater fish of the family Salmonidae found in Lake Constance (Switzerland, Germany and Austria). References

* Coregonus, arenicolus Freshwater fish of Europe Lake Constance Vulnerable animals Taxa nam ...

'' for the''Sandfelchen''. The common name fera is still also used for fish that continue to live in Lake Geneva, but it now refers to the introduced '' Coregonus palaea''.Maurice Kottelat & Jörg Freyhof (2008
''Coregonus fera''
The IUCN Red List of Threatened Species v. 2015-4

Biology

The true fera was a

benthopelagic The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer o ...

that swam in the water column near the lake bottom, feeding upon

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

Spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aqua ...

occurred from February to mid-March.

Extinction

Together with the similarly extinct

gravenche The gravenche (''Coregonus hiemalis''), also known as the Lake Geneva whitefish or the little fera, is a presumably extinct freshwater fish from Lake Geneva in Switzerland and France. Description The gravenche was a species of freshwater white ...

(''Coregonus hiemalis''), the fera was one of the most caught freshwater fishes in Lake Geneva. In 1890 these two fishes constituted 68% of the total captures in the lake. Due to a combination of

overexploitation Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term ap ...

and heavy hybridisation with introduced ''

Coregonus ''Coregonus'' is a diverse genus of fish in the salmon family ( Salmonidae). The ''Coregonus'' species are known as whitefishes. The genus contains at least 68 described extant taxa, but the true number of species is a matter of debate. The ty ...

'' species, it became extremely scarce and was last seen in Lake Geneva in 1920.Christian Trépey
Corégone (Féra - Palée)
www.plongee-passion.ch

References

* Maurice Kottelat: ''European Freshwater Fishes. An heuristic checklist of the freshwater fishes of Europe (exclusive of former USSR), with an introduction for non-systematists and comments on nomenclature and conservation''; Biologia: Section Zoology vol. 52/5, Slovak Academic Press, Bratislava 1997, *

External links

Catalog of Fishes Corregonus fera
{{DEFAULTSORT:Coregonus Fera fera Taxa named by Louis Jurine Fish described in 1825 Freshwater fish of Europe Lake fish Lake Geneva Extinct animals of Europe Fish extinctions since 1500