The variety of life strategies among representatives of the genus Salvelinus suggests the existence of resident (lacustrine or riverine) and migratory forms. Resident brook populations of char are characterized by small size and short lifespan (up to 8–11 years), low fecundity, and often a juvenile (pedomorphic) appearance. Such populations are most common among the northern Dolly Varden trout S. malma, less common among the southern Dolly Varden trout S. curilus, and are extremely rare among the Arctic char S. alpinus. In 2024, an unusual population of dwarf char S. alpinus complex was discovered in a small watercourse in the upper Kolyma River basin. The fish were collected in shallow channels of the Enkon River in the middle of a wide, flat valley (aufeis) in the middle reaches of the Burkandi River at an altitude of approximately 950 m above sea level. The captured dwarf brook char specimens are characterized by extremely slow growth, a juvenile appearance, and a short lifespan compared to lacustrine stocks. Similar stocks can be expected to be found in other sections of watercourses isolated from the main channel by physical barriers. In northeastern Asia, potential habitats for similar dwarf char populations may include sections of rivers and streams located above the aufeis, which are common in this area.
M. B. Skopetc (Wed,) studied this question.