Dysplastic lesions and abnormalities in amphibians associated with environmental conditions.

High incidence of developmental anomaly and tumor-like dysplasia of osteochondrous tissue of hind limbs has been detected in frogs and toads the larval development of which has taken place in water, contaminated with sewage. Correlation between frequency of dysplasia and the level of water oxidation has been noted. Study on histogenesis of the marked tumor-like dysplasia were performed. It is assumed that the major mechanism responsible for anomaly consists in cytotoxic effect of teratogenic agent and that the differentiation lesion of cartilaginous tissue is caused by blocking of maturation and death of chondrocytes.