Morphometry and fluctuating asymmetry of the gibel carp (Carassius gibelio) in bodies of water with different types of hydrology

This work examines the morphometric characteristics and fluctuating asymmetry of gibel carp, Carassius gibelio (Bloch, 1782) populations in water bodies within the same basin under varying hydrological conditions in the Ob-Irtysh basin, Western Siberia. By conducting measurements and analyses of meristic features, we determined the extent to which fish morphological characteristics are influenced by their natural habitat and hydrological regime. Cluster analysis revealed that gibel carp populations from reservoirs with a permanent water supply share similar morphometric parameters and exhibit lower asymmetry than populations from isolated or irregularly filled reservoirs. As a result of morphometric assessment, fluctuating asymmetry was shown to be an important and convenient indicator of adaptive changes and the overall state of the population. The data obtained emphasize the need to account for hydrological factors in ecological and biological studies and in monitoring species threatened by habitat change. The results of the study can be useful in monitoring the state and restoration of aquatic ecosystems.