Amphibians as bioindicators of environment condition in the Middle Volga region: phenetic structure of population

In 2005-2006 years phenetic structure of marsh frog ( Rana ridibunda Pallas, 1771) population was studied in Middle Volga region. It was established that in the conditions of high anthropogenic transformation intrapopulational diversity decreases and the proportion of rare phenotypes increases in most populations.