Thymallus

Thymallus Temporal range: to Present
Arctic grayling (Thymallus arcticus)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Salmoniformes
Family:	Salmonidae
Subfamily:	Thymallinae
Genus:	Thymallus Linck, 1790
Type species
Thymallus thymallus (Linnaeus, 1758)
Species
(see text)

Thymallus is a genus of freshwater fish in the salmon family Salmonidae; it is the only genus of subfamily Thymallinae. The type species is Thymallus thymallus, the grayling. The species in the genus are generically called graylings, but without qualification this also refers specifically to T. thymallus.

The fishes of this genus are native to the northern parts of the Palearctic and Nearctic ecozones, ranging from the United Kingdom and northern Europe across Eurasia to Siberia, as well as northern North America. T. thymallus, the grayling, is widespread in Europe, and T. arcticus, the Arctic grayling, is widespread throughout Eurasia east of the Ural Mountains and in the Nearctic. The other species have more localized ranges in northern Asia.

The Thymallus species are distinguished from other members of the salmon family by their larger scales, their small mouths with teeth on the maxillary bone, and most striking of all, their showy, sail-like dorsal fins. This fin is longer in males and highly colourful, with spots of red, orange, purple or green. The body is also colourful; the dorsal surface is a dark purplish to bluish black or gray, grading to dark blue or silver gray on the flanks and gray or white on the belly. The body is further decorated with a smattering of small dark spots; these are much more numerous in juveniles.

The longest of the graylings is the Arctic grayling, T. arcticus, at a maximum length of 76 cm (30 in) and a maximum weight of 3.8 kg (8.4 lb). T. thymallus, while somewhat shorter - 60 cm (24 in) - may weigh significantly more, 6.7 kg (15 lb). The fishes of this genus may live for 18 years or more.

...
Wikipedia