Formation and development of the Black Sea-Caspian kilka Clupeonella cultriventris (Clupeidae) in the Rybinsk reservoir

We studied the state and development of the population of the Black Sea-Caspian kilka Clupeonella cultriventris in the Rybinsk reservoir from 1994 to 2010. The population dynamics, the rate of growth of the kilka, as well as its food relationships with other fish species of the pelagial community, were analyzed. It was found that the period of exponential increase in the numbers was replaced by the period of interannual fluctuations. With the development of the population, tendencies for a decrease in the rate of growth of the kilka and aggravation of its food relationships with other species are revealed, which is determined by changes in the structure of pelagic aggregations of fish. One of the most significant environmental factors determining dynamics of the numbers and state of the kilka population in the northernmost part of its modern range is water temperature.