Influence of copper sulphate on the water and electrolyte balance of the freshwater snail Bulinus (Bulinus) tropicus / Van Aardt, W.J., Coertze, D.J.

water and electrolyte balance of Bulinus (Bulinus) tropicus, a freshwater pulmonate, was determined when subjected to different sublethal concentrations of copper sulphate. It was found that the lethal dose (LD50), which is the dose lethal to 50% of the snails, is 1,0 ppm in water of pH 8,5. Increasing dosages disturb the ionic and water balance. Haemolymph concentrations of Na+, Ca2+ and Cl- decrease markedly. The rates of ion influx and efflux for Ca2+, Na+, Cl- and 3H2O, measured with their corresponding radioisotopes, were drastically changed. The results indicate that the physiological effects of copper are not limited to particular organs or tissues but probably occur throughout the snail body. The possible effects of copper sulphate on the integumental exchange mechanisms for Ca2+, HCO3-, Na+, K+ and Cl- are discussed