Thymallus.

Thymallus, commonly known as graylings, is a genus of freshwater fish in the family Salmonidae. Species belonging to this genus are easily recognized by their large, sail-like dorsal fins. For a long time, the European grayling (Thymallus thymallus) was considered the only grayling species native to Europe. However, in 2019, the Loire grayling (Thymallus ligericus) was described as a distinct species.
According to FishBase, there are currently 15 recognized species within this genus, though this number remains debated. Research published in 2020 also supported the revalidation of the Adriatic grayling under the name Thymallus aeliani, bringing the total number of species to 16.

Species native to Europe.

Thymallus aeliani (North Adriatic River basin - Italy, Slovenia and Switzerland)
Thymallus ligericus (upper Loire River basin - France)
Thymallus thymallus (Europe)

Other species of this genus.

Thymallus articus (Canada, Alaska and Siberia)
Thymallus baicalensis (Yenisey river basin, lake Baikal and Ob river basin - Rusia)
Thymallus brevipinnis (lake Baikal - Rusia)
Thymallus brevirostris (Mongolia)
Thymallus burejensis (Rusia)
Thymallus flavomaculatus (East Rusia, Sea of Japan and Sea of Okhotsk)
Thymallus grubii (Amur river basin - Russia, China and  Onon river basin and Kherlen river basin - Mongolia)
Thymallus mertensii (East Rusia)
Thymallus nigrescens (Lake Huvsgul - Mongolia)
Thymallus pallasii (East Siberia)
Thymallus svetovidovi (upper Yenisey - Rusia and Mongolia)
Thymallus tugarinae (Lower Amur - Rusia and China)
Thymallus yaluensis (Yalu - China and North Korea)