ABSTRACT
The influence of EDTA on B. glabrata has been investigated. Newly hatched snails were exposed to concentrations of EDTA from 1 to 64 ppm, and young (diameter of 6 mm) snails to concentrations of 50, 80 and 100 ppm, for periods of 90 days. Fifty percent reduction of egg productivity has been caused by concentration of 16 ppm of EDTA while 50% of mortality has occurred at about 70 ppm. The calcium and iron content both in treated and non-treated young snails have been estimated by atomic absorption photometry. The uptake of calcium was 40, 83 and 90% less for calcium and 37, 77 and 81% less for iron as compared with the untreated group. The calcium content of the shell was 5--15 times greater than that of the soft body, while the iron content of those two parts was in the proportion of 1:1. These proportions were maintained constant in the treated and non-treated groups. The interference of increasing concentrations of EDTA has resulted in the proportional reduction of growth-rate, reproduction rate and of longevity of the exposed snails.
