CHARACTERISTIC FEATURES OF NUTRITION HABITS INHERENT TO FISH SPECIES FOUND IN THE LITTORAL ZONE OF THE LAKE ONEGO
Characteristic nutrition features of massive fish species found in the littoral zone of the lake Onega are considered in the article. The intensive distribution of such invasive species as Baikal amphipods Gmelinoides fasciatus in the lake Onega has led to its significant numerical strength and growth in biomass. Our research showed that Baikal amphipod became an important ingredient (up to 50 % of the food bolus) in the diet of perch fish - perch and ruff in the northern, western and eastern coasts. This new object of zoobenthos is not included into the diet of local roach - a rather mass species of carp fish. The Baikal crustacean was found in the diet of some types but not all types of fish inhabiting investigated in our research areas of Onega Lake. An assumption can be made that the aboriginal fish will start consuming amphipod once it spreads in multiple shallow areas.