No abstract

Treatment with sublethal doses of Cu (100 µg.l -1 ) and Cd (250 µg.1 -1 ) induces toxic effects in Physa acuta Drap., whereas V (250yg.l~*) does not. These results are correlated to the accumulation in soft tissues of Cu and Cd, while the non-accumulation of V is related to some excretion or inactivation. Three main fractions of metalbinding compounds with different molecular weights were isolated. Some conclusions are drawn about the significance of the presence of different chelating systems in relation to the detoxification of snails surviving in polluted environments.