“Freshwater Components” in the Populations of Whitespotted Char Salvelinus leucomaenis (Salmonidae) in the North of the Species Range (Kamchatka)

Abstract

The variety of types of life strategy and the structure of the populations of whitespotted char Salvelinus leucomaenis (Pallas, 1814) are considered at Kamchatka. At the north of the species range, the populations of whitespotted char are heterogeneous. The main role in reproduction belongs to anadromous whitespotted char, but there are also the groups in the populations that realize their life cycle exclusively in fresh waters. Dwarf males are common in the rivers of different types. In the geomorphologically complex river (Kol), there is also the river populations of rheodromous whitespotted char, represented by males and females. Favorite biotopes (blockages and creases of woody material on deep reaches, found only in foothill rivers) are key parameters predetermining the presence of a river population of rheodromous whitespotted char. At the north of the species range, the variety of individuals with different types of life strategy in whitespotted char is comparable to that observed in the southern parts, in particular, in the basin of the Sea of Japan, which is considered the zone of the ecological optimum of the species.