title: Intragroup variability of growth in perch, Perca fluviatilis L., 1758 (Percidae) in waterbodies in the watershed of the Middle Ishim
abstract: As a result of the research carried out in 2016-2021 on the lakes of the Shchuchinsk-Borovoe resort area and on the Ishim River, material was obtained on the intragroup variability in the growth of perch. The absence of sexual variability was noted, which is explained by the relative stability and positive influence of environmental factors. The revealed generational variability of growth showed both a noticeable decrease in its rates in Lake Shchuchie and a significant increase in Lakes Borovoe
journal: Limnology and Freshwater Biology