Thecamoebians as a tool for reconstruction of paleoenvironments in some Italian lakes in the foothills of the Southern Alps (Orta, Varese and Candia)

A study of thecamoebians was carried out on three sediment cores collected in three Northern Italian lakes (Orta, Varese, Candia). The recognition of distinct morphotypical populations (''morphs'') within three species of thecamoebians in varying paleolimnological settings resulted in a refined understanding of the environmental parameters controlling their distribution. For example, D. proteiformis morph ''proteiformis'' is well adapted to environments rich in organic matter and sulphides whereas D. proteiformis morph ''rapa'' tolerates polluted and acidified waters (presence of copper sulfates, ammonium sulfates, high content of ammonium and nitrite nitrogen, and water with pH values between 3.9 and 4.5). Although most questions about the ecology of thecamoebians are still unresolved, this study strongly suggests that with further research these protozoans can be a valuable tool for paleoenvironmental reconstructions and detection of environmental deterioration.