Smallmouth char (Salvelinus elgyticus)
The head and body are grayish-yellow with a dull metallic tint; the belly is gray-white. The paired fins are orange-red, the anal fin -gray-yellow. On the body sides there are small and large, rounded, white or orange spots. During the spawning, the proportions of the body and head do not change, but the colors become darker. The air bladder is hot pink.
The number of the gill rakers is unusually high for a char (44-53), but the scales in the lateral line (105-125) and vertebrae (59-64), on the contrary, are few. This fish differs from all other chars by its morphology and structure of the karyotype.
Endemic small-mouth char is a common prey of the Boganid char in the Elgygytgyn Lake. This fish lives at different depths from shallows near the lake shore to 140 m (rarely), but in most cases (except during the spawning period) it is dwelling in the middle and upper parts of the lake hollow slopes. These chars also appear in shallows in spring when the lake is covered with ice. This species is characterized by a distinct rhythm of diurnal activity. In shallows and near the surface it appears only at dusk or at night, and only in the areas protected from the waves.
The spawning takes place in September in shallows in the southern part of the lake with depths of 1.5–3 m, on the bottom of small pebbles. The smallmouth char grows extremely slowly; the biggest specimen on record was 24 cm long — it was 26 years old! The fertility is very low: from 380 to 770 eggs (average 550).
The species is listed in the “List of World’s Endangered Fish” and on the pages of the Red Book of the Russian Federation.