Chronic toxicity of acetone in the fresh water snail Lymnea stagnalis.

With water of total hardness of 230 mg/l of CaCO3 all the tried concentrations (0.1, 0.2, 0.4 and 0.6%) of acetone induced a decrease in the growth of the young pond snails. For older snails, a 0.4% concentration was the threshold at which an inhibitory effect of the shell growth was observed. From the 0.1% concentration a decrease in the shell mineralization was recorded. In the range of 0.1--0.6% concentrations, the decrease of the fecundity varied from 3% to 31%. At lowest concentrations, only the number of egg-masses/snail was reduced. At the 0.6% level a lower number of eggs/egg-mass was added. The 0.6% concentration of acetone disturbed only the fertility of the eggs; lowest concentrations significantly increased the frequency of polyembryony.