摘要：

One of the most frequent metalloid and metallic elements in the Earth's crust are silicon and aluminium. Silicon is an essential element in lower life forms and its biological function in higher forms of life is not known. Acidification of water ecosystems and lowering the pH value increases solubility of metal ions e. g. aluminium, which at higher concetrations becomes toxic. Aluminium is a known neurotoxin, which interferes with the synthesis of neurotransmitters in the central nervous system of mammals. We analyzed the effect of aluminium (80 mg/dm3, 100 mg/dm3) in neutral and acidic media, pH 7.1 and 5.2 and sublethal doses of silicon (0.17 g/dm3, 0.20 g/dm3, 0.23 g/dm3, 0.25 g/dm3, 0.27 g/dm3, 0.30 g/dm3) on Polycelis felina (Daly.) respectively. It has been established the toxic effect of aluminium in applied concentrations upon planarian species. Aluminium in acid media induced higher mortality, stronger morphological and behavioural changes and more extensive tissue damage. Also silicon, depending of dosage of applied concentration, causes mortality, decephalization, depigmentation, morphological and cyto - histological changes. Using HPLC a great amount of silicon was found in the body tissue. Most intensive damages were established on the first and second day after the treatment in the experiment with aluminium in acidic media and on the second and third day after the treatment in the experiment with silicon. On histological slides of treated planarians with aluminum and silicon were visible same changes: damages to the epidermis, degradation of tissue, decomposition of mucous layer and an increased number of rabdites and neoblasts.

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