Lake Geneva white-fish
Encyclopedia
The gravenche also known as the Lake Geneva whitefish or little fera, is a presumably extinct freshwater fish from Lake Geneva
in Switzerland
and France
.
described it as subspecies of Coregonus lavaretus in 1958, other experts like Maurice Kottelat
regarded it as a full species endemic to Lake Geneva
. It reached a length between 25 and 32 centimetres.
, that means it occurred near the ground in very deep waters. It was fed from zooplankton
. The spawning
was in mid-December.
(Coregonus fera) it was one of the most caught freshwater fish in the Lake Geneva
in the late 19th century. In 1890 the fishing quota of these two fish made 68% of all fish caught in Lake Geneva. Overfishing drove the gravenche to near extinction in 1920 and it was last seen in 1950.
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 gravenche is disputed because there are no specimens in museums. While 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 it as subspecies of Coregonus lavaretus in 1958, other experts like 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...
regarded it as a full species endemic 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...
. It reached a length between 25 and 32 centimetres.
Biology
The gravenche 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 in mid-December.
Extinction
Together with the likewise extinct feraCoregonus fera
Coregonus fera, commonly called the true fera is a presumed extinct freshwater fish from Lake Geneva in Switzerland and France.-Description:...
(Coregonus fera) it was one of the most caught freshwater fish in the 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 the late 19th century. In 1890 the fishing quota of these two fish made 68% of all fish caught in Lake Geneva. Overfishing drove the gravenche to near extinction in 1920 and it was last seen in 1950.