The objective of the study is to screen for morphological, biochemical and histological changes induced by six widely used pesticides (Reldan 40EC, Actara 25WG, Tilt 250EC, Champion 50WG, Fusilade Forte, Dual Gold 960EC) in the amphibian species Pelophylax ridibundus (Pallas, 1771). Highly degenerative changes were observed in animals cultured at 22-24°C, compared to those cultured at 4-6°C. The hepatosomatic index increased upon exposure to almost all of the pesticides, the erythrocyte number decreased upon exposure to all pesticides except Reldan 40EC, while leucopenia was observed only for Reldan 40EC and Actara 25WG. Hyperglycemia was observed upon administration of pesticides (except Champion 50WG and Fusilade Forte, for which hypoglycemia is registered), while a decrease in cholesterol levels was induced by nearly all pesticides. Triglycerides varied only slightly. The results suggest that chronic pesticides exposure can lead to alteration of various indices, as well as to hepatic lesions in amphibians.
Keywords: Histological changes; Pelophylax ridibundus; Pesticides; Physiological indices.