Size-age composition and growth of ruff Gymnocephalus cernuus L. in the top part of Volga reach at Kuibyshev water reservoir and Kazanka river

Size-age composition and growth of ruff in 2008, 2011 and 2014 in upper Volga reach of Kuibyshev water reservoir and Kazanka river is considered. It is established that size and weight composition is significantly different in both years at the water reservoir and Kazanka river. The mean parameters of length and weights are lowest in river. Age structure is represented by individuals from 0+ to 5+. Dominate age group in the water reservoir and Kazanka river was 3+ and 2+ accordingly. There is no significantly differences growth of male and female in Kazanka river. Body length of the same age groups was lowest.