Вiotic sympatry of whitefish Coregonus lavaretus (L.) in Kuetsjarvi lake (Pasvik river system, Murmansk region)

For the first time the whitefish Coregonus lavaretus biology was investigated in detail. The study was held in subarctic lake Kuetsjarvi (lower reaches of the Pasvik river), which is one of the most technologically-contaminated water bodies of the Euro-Arctic region. Based on this study, four ecological morphs of fish were identified: slowly growing and fast-growing sparsely rakered whitefish, slowly growing and fast-growing densely rakered whitefish. Specialization of the whitefish in a certain kind of resources determines their morphological and behavioral differences, spatial differentiation and ultimately various ecological niches.