Description
Eesti: Pärnu jõe kiisk
English: Eurasian ruffe (Gymnocephalus cernuus) in the Pärnu River, Estonia.
Español: Acerina (Gymnocephalus cernuus) en el río Pärnu, Estonia.
Polski: Jazgarz (Gymnocephalus cernua) w rzece Parnawa w Estonii.
Português: Acerina-eurasiana (Gymnocephalus cernua) no rio Pärnu, Estônia.
Русский: Обыкновенный ёрш (Gymnocephalus cernuus) в реке Пярну, Эстония
Date 6 January 2010
Source Own work
Author Tiit Hunt https://commons.wikimedia.org/wiki/User:Tiithunt
Source: https://commons.wikimedia.org/wiki/File:Gymnocephalus_cernuus_P%C3%A4rnu_River_Estonia_2010-01-06.jpg

The Eurasian ruffe (Gymnocephalus cernua), also known as ruffe or pope, is a freshwater fish found in temperate regions of Europe and northern Asia. It has been introduced into the Great Lakes of North America, reportedly with unfortunate results, as it is invasive and is reproducing faster than other species. Its common names are ambiguous – "ruffe" may refer to any local member of its genus Gymnocephalus, which as a whole is native to Eurasia. Order: Perciformes, Family: Percidae.
Synonyms:
Perca cernuus Linnaeus, 1758
Acerina cernua (Linnaeus, 1758)
Holocentrus post Lacépède, 1802
Cernua fluviatilis J. Fleming, 1828
Acerina vulgaris G. Cuvier, 1829
Acerina fischeri Eichwald, 1873
Acerina czekanowskii Dybowski, 1874
Acerina cernua danubica Vladykov, 1931 (ambiguous)
Acerina cernua essipovi Burmakin, 1941