Effect of Cadmium on the Epidermic Structure of Bufo arenarum Tadpoles: Influence of the Chemical Composition of the Incubation Media

Abstract

Epidermic alterations in premetamorphic Bufo arenarum tadpoles were analyzed by scanning electron microscopy after exposure to sublethal cadmium concentrations in distilled water, in 141 mOsm solutions of mannitol and NaCl and in artificial pond water of 5 mOsm. Animals kept in NaCl solutions and in artificial pond water containing Cd did not show epidermic alterations. Cadmium in distilled water and in mannitol solutions caused loosening of cellular binding, cellular deformation and detachment and perforations of the epithelial membrane. Observed alterations were rapid and independent of the incubation media osmolarity. The interpretation of results must be linked to the competition between Cd and Ca, which is recognized as a basic factor in cellular adhesiveness.