Present state of population of lake frog Rana ribunda Pallas, 1771 (Anura, Amphibia) in the Republic of Bashkortostan according to the polymorphism of spinal coloration patterns

The article shows the results of research (carried out in July and August, 2008) on polymorphism of back, neck and abdomen coloration patterns in 4 populations of lake frogs on the territory of Bashkortostan. The chemical analysis of water in habitats of Rana ridibunda and estimation of habitat urbanization helped to define 3 groups of anthropopression: moderate, high, and critical. The dependency of spinal coloration patterns variety from pression caused human intrusion has been found. According to verified statistical data critical anthropopression results in poor variety of coloration patterns (2,06±0,24) in comparison with high (2,517±0,179; 2,99±0,237) and moderate (3,49±0,183) levels of anthropopression.