Gravenche (Coregonus hiemalis)
The Graveche, also known as Kilch, Kleine Fera or Lake Geneva Whitefish was endemic to Lake Geneva, where it was formerly one of the most commonly caught species.
The species reached lengths of 25 to 32 cm, it lived mainly among or near the lake’s bottom where it fed on tiny to tiniest organisms.
***
Despite being one of the most common species of the lake, the species was already disappearing during the 19th century, so the catching size for this species in Switzerland was officially set to above 20 cm in 1887.
This effort, however, came too late, the Graveche disappeared completely and is now globally extinct.
*********************
(not in copyright)
*********************
edited: 21.03.2018