Effects of cadmium exposure on bioaccumulation and larval growth in the frog Rana ridibunda

The bioaccumulation of cadmium and the effect on growth of larvae of the frog Rana ridibunda after exposure to Cd for 15 and 30 days was investigated. The 96-h LC50 value was 71.8 ppm. The water content of all the tadpoles exposed to all cadmium concentrations was higher than that of controls. There was a tendency for the animals exposed to Cd to retard their growth. Mortality rates at 15 days exposure increased with increasing cadmium concentration and remained constant in all the cadmium concentrations at 30 days exposure. Cadmium accumulation was higher in the 15 days exposed tadpoles, compared to that of 30 days exposure. Growth retardation may be a factor contributing to the declining of amphibian populations, since they, because of their smaller size, spend more time in more vulnerable stages, becoming thus more susceptible to predators. ©