Toxic effects of aluminium, chromium and cadmium in intact and regenerating freshwater planarians

The effects of exposure to heavy metals were analyzed in the intact and regenerating planarian Dugesia etrusca. Al(3+) and Cr(3+) were lethal at 1.5 mM concentration. Intact specimens, treated with Al at lower concentrations, exhibited a variety of sublethal responses; Al was significantly more toxic than Cr. Alterations in the cephalic regeneration of decapitated planarians were observed with bath metals. Cd(2+) was tested at concentrations ranging from 0.18 mu M to 18 mu M. Until 1.8 mu M, this metal did not produce any detectable sublethal responses in intact planarians, whereas higher concentrations were lethal. Sublethal Cd concentrations did not show any visible effect on cephalic regeneration. (C) 1998 Elsevier Science Ltd. All rights reserved.