The gravenche was a species of freshwater fish native only to Lake Geneva, one of the Alpine lakes that straddle the border between France and Switzerland. The fish were apparently once so common in the lake that it alone accounted for two-thirds of all of the fish caught in Lake Geneva. Due to overfishing, the population of gravenche began to decrease rapidly in the early 20th century; the last known sighting was in 1950, and the species is now considered extinct.