Coregonus fera
Encyclopedia
Coregonus fera, commonly called the true fera
is a presumed extinct freshwater fish
from Lake Geneva
in Switzerland
and France
.
described Coregonus fera as both native to Lake Geneva
and Lake Constance
. The coregonines from Lake Constance
were named Sandfelchen. In 1997 Maurice Kottelat
made a revision and used the name Coregonus fera for the fera and Coregonus arenicolus for the Sandfelchen.
The fera reached a length between 35 and 40 centimetres.
, that means it occurred near the ground in very deep waters. It was fed from zooplankton
. The spawning
was from February to mid-March.
. Due to overexploitation
in combination with the heavily hybridisation with introduced coregonus species it became extremely scarce in the 1920s. It was still present in 1950 but was not found again in 1958.
Fera (fish)
Fera is a locally name for several fish species of the genus Coregonus from Switzerland, and France, in particular Savoy. The true fera referred to the species Coregonus fera which was endemic to Lake Geneva but is now extinct. The ”fera” is served as food fish in Switzerland and Savoy, but this...
is a presumed extinct freshwater fish
Freshwater fish
Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity...
from Lake Geneva
Lake Geneva
Lake Geneva or Lake Léman is a lake in Switzerland and France. It is one of the largest lakes in Western Europe. 59.53 % of it comes under the jurisdiction of Switzerland , and 40.47 % under France...
in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
and France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
.
Description
The status of the fera is disputed. In 1950 Emile DottrensEmile Dottrens
Emile Dottrens was a Swiss zoologist and nature conservationist. He became a scientific assistant for zoology at the Natural History Museum of Geneva in 1942 and was the director of that museum from 1953 to 1969. He wrote several articles about the Swiss freshwater fish species from the genus...
described Coregonus fera as both native to Lake Geneva
Lake Geneva
Lake Geneva or Lake Léman is a lake in Switzerland and France. It is one of the largest lakes in Western Europe. 59.53 % of it comes under the jurisdiction of Switzerland , and 40.47 % under France...
and Lake Constance
Lake Constance
Lake Constance is a lake on the Rhine at the northern foot of the Alps, and consists of three bodies of water: the Obersee , the Untersee , and a connecting stretch of the Rhine, called the Seerhein.The lake is situated in Germany, Switzerland and Austria near the Alps...
. The coregonines from Lake Constance
Lake Constance
Lake Constance is a lake on the Rhine at the northern foot of the Alps, and consists of three bodies of water: the Obersee , the Untersee , and a connecting stretch of the Rhine, called the Seerhein.The lake is situated in Germany, Switzerland and Austria near the Alps...
were named Sandfelchen. In 1997 Maurice Kottelat
Maurice Kottelat
Dr. Maurice Kottelat is a Swiss ichthyologist.In 1976 he entered the University of Neuchâtel where he obtained his diploma in 1987. In 1980 he went to Thailand where he began his field research on Southeast Asiatic and Indonesian fresh water fish species...
made a revision and used the name Coregonus fera for the fera and Coregonus arenicolus for the Sandfelchen.
The fera reached a length between 35 and 40 centimetres.
Biology
The fera was a benthopelagic freshwater fishFreshwater fish
Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity...
, that means it occurred near the ground in very deep waters. It was fed from zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
. The spawning
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
was from February to mid-March.
Extinction
Together with the equally extinct Gravenche (Coregonus hiemalis) it was one of the most caught freshwater fishes in the Lake Geneva. In 1890 the fishing quota of these two fishes made 68% of all caught fishes in Lake GenevaLake Geneva
Lake Geneva or Lake Léman is a lake in Switzerland and France. It is one of the largest lakes in Western Europe. 59.53 % of it comes under the jurisdiction of Switzerland , and 40.47 % under France...
. Due to overexploitation
Overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource...
in combination with the heavily hybridisation with introduced coregonus species it became extremely scarce in the 1920s. It was still present in 1950 but was not found again in 1958.