Effects of Aluminum in the striped venus clam, Chamelea gallina

Aluminum is the most abundant metal in the Earth's crust and is widely used in everyday life. In sea waters, the presence of dissolved Al is naturally limited to a few micrograms per litre, however anthropogenic activities tend to alter its concentration. Toxic effects caused by this metal have already been demonstrated on several taxa, as well as a direct correlation with various diseases, including neurodegenerative ones. Since bivalves proved good bioindicators for environmental and possibly human health, we tested by histochemical methods the effects of Aluminum on the muciparous tissues of the striped venus clam, Chamelea gallina. Aluminum chloride at concentrations of 25, 50, and 200 µM, respectively were administered to experimental groups of twenty clams housed under controlled conditions. Image analysis of tissues stained by conventional and lectin-histochemistry indicated both qualitative and quantitative alterations of the mucous secretion produced by the gills and feet epithelia of the clams. The acidity and viscosity of the mucus itself is altered, with possible repercussions on the health and survival of animals.