Siberian sucker (Catostomus catostomus rostratus) populations inhabit lake–river systems, belonging to the tributaries of the upper and middle reaches of the Kolyma River. The size, age, and sex structures of the studied populations are presented. It is shown that, despite the prevailing belief that this subspecies is exclusively riverine, it is common and even abundant in some mountain lakes of the Kolyma Basin. The data on the parasite fauna of the studied Siberian sucker populations suggest their isolation from the main channel of the middle and lower reaches of the Kolyma River. The Siberian sucker populations from Lake Darpir and the Ui lake–river system may be relicts isolated since the Late Pleistocene.
Khamenkova et al. (Sun,) studied this question.