Growth characteristics and rates of the mash frog Pelophylax ridibundus Pall. introduced into water bodies of the Middle Urals

The characteristics and growth rates of mash frogs introduced upon the completion of metamorphosis into the cooling ponds of heating stations have been studied. The age composition of frog populations has been determined. It has been shown that an extra year must be added to the visible adhesion lines in the tissue of long bones. It has been found that the population of mash frogs inhabiting the Verkhnii Tagil Reservoir is characterized by not only a longer life span than in the Reftinskoe Reservoir, but also by a sufficiently high frequency of occurrence in the samples of older age groups.