Assessment of Ecological Status of Two Rivers with Different Types of Anthropogenic Pollution in Southern Bulgaria Based on the Level of Fluctuating Asymmetry in the Populations of Marsh Frog Rana ridibunda (Amphibia: Ranidae)

The degree of manifestation of the indicators of fluctuating asymmetry (FA) was studied in the populations of Rana ridibunda in two of the most polluted river ecosystems in Southern Bulgaria. The integral indicator of developmental stability, evaluation of the ecological condition parallel to the data of physicochemical analysis was performed. It was found that the variations in genetic homeostasis in the populations of R. ridibunda in a habitat under conditions of anthropogenic pollution occur independently on the type of toxicants, but the degree of violation expression in the form of FA depends on the nature of the pollution.