New Data on Morphological Features of the Branchial Apparatus of Sparsely Rakered and Medium Rakered Morphs of Whitefish Сoregonus lavaretus (L.) from the Largest Subarctic Lake

The distribution and feeding of the ecological morphs of whitefish is studied in Lake Imandra, the largest subarctic water body. Data on the hydrochemical and hydrobiological characteristics of the reaches of the lake, as well as on the morphological features of the whitefish branchial apparatus with low and medium gill raker number, are obtained. A relationship between feeding preferences of whitefishes and size characteristics and trophic levels of the habitats is revealed.