Pollution tolerant protozoa in polluted wetland

Abstract This study for the first time confirmed that eight dominating protozoan species, Cryptomonas erosa , Euglena axyuris , Euglena caudate , Euglena gasterosteus , Euglena acus , Vorticella campanula , Vorticella convallaria and Epistylis lacustris , were the pollution tolerant species at chemical oxygen demand 54–104 mg/L. These species cannot be used as indicator for clean water quality as commonly believed. The protozoa can be actively participating in the energy transfer chain between nano-planktonic and higher plants in polluted wetlands.