Arctic char (Salvelinus alpinus)
The Arctic char breeds in the lakes or in lake-like river pools with slow current. This species inhabits deep mountainous lakes located in the regions with warm climate. There are many such water bodies, for example, in the Alps. Such relict char populations dwelling here inhabit the depths where the water is cold year-round.
Anadromous Arctic char go into the rivers of the Arctic Ocean and northern part of the Atlantic Ocean. The populations of anadromous char are confined to the rivers with suitable lakes in the basin. Both smolts and adult anadromous chars wintering in the river go down into the sea for feeding in spring and early summer. In the second half of summer, the fish enter freshwater for spawning and wintering.
In the north-west of Russia among the diverse colors of the chars prevail gray, pink and red. The fish coming from the sea have “pelagic” color typical for salmonids with dark back, silver sides and a white belly. In many large and deep lakes, the resident char also acquire silver coloration. In shallow water bodies, such silver char are rare.
Anadromous char usually are 34 to 70 centimeters long; their weight is from 0.4 to 2.4 kg. As a rule, lake-resident chars have a length of 25 to 45 cm, and their mass is 120-850 g. Some large lakes have deep-water forms of the chars.
Char often inhabits lakes, forming resident populations. In the European North, all lake-resident chars reproduce in the lake, and do not go for spawning into the inlets or ourlets. The farther south, the more the char is forced to adhere to the lake depths, where it is cool all year round.
Arctic char lives in many mountainous lakes of Siberia located in the basins of the Yenisei and Lena rivers. Some populations of the species, for example, the Davatchan from the Lake Frolikha, are listed in the Red Book.