Coregonus fera
Fera (Coregonus fera )
The FERA (Coregonus fera ) is an extinct species of the genus Coregonus, which was endemic in the Lake Geneva.
Features
The FERA reached a standard length of 550 mm. The back was slightly bent. The dorsal profile of the head and the mouth was straight. There were 21 to 28 gill rakers. The back was brownish-gray with a yellowish tinge. The flanks were greenish or bluish. The fins showed a pinkish tinge with age. The skull was greenish yellow with pale dots that adopted a more intense color with age.
Way of life
In summer, the FERA of insects fed. In winter, they moved into deeper waters where their food included zooplankton. The spawning period was from February to mid - March.
Extinction
Together with the also extinct Gravenche (Coregonus hiemalis ) belonged to the FERA to the most caught fish species of Lake Geneva in the late 19th century and early 20th century. 1890 made the catch rates of these two species from 68 percent of all fish caught in Lake Geneva edible fish. Due to the eutrophication of Lake Geneva, overfishing and the strong hybridization with introduced coregonids as the Palée the FERA was extremely rare in the 1920 's. The last existence of evidence should have given it to 1950; around 1958 this species was, however, no longer be detected.
Systematics and present use of the name Fera
The systematic status of the FERA has long been controversial. While Louis Jurine described the taxon in 1825 as a distinct species, it was considered by Heinrich Rudolf Schinz only as a synonym of Coregonus maraena. 1950 used Emile Dottrens the binomials Coregonus fera both the coregonids in Geneva as well as in the Lake Constance, where he described the fish in Lake Constance whitefish than sand. Revised in 1997 Maurice Kottelat this system. As Coregonus fera only the taxon was designated in the Lake Geneva. The sand was whitefish Coregonus neubeschrieben as arenicolus. Today's use of the name refers to the FERA 1923 was introduced in Geneva Palée (Coregonus palaea ).