Euglenoid Flagellates in Ecotoxicological Research: Progress and Perspectives

Euglenoids are a common component of primary producers in high acidic and organic shallow freshwater systems. They are free-living photosynthetic motile flagellates exhibiting rapid responses to various external stimuli including chemical pollution. The unique combination of diverse physiological processes of Euglena such as photosynthesis, movement, and orientation offers a range of sensitive criteria that respond to aquatic pollutants. This has led to the development of several acute and chronic assay methods to monitor the adverse impacts of potent toxicants in aquatic ecosystems. Euglenoids also reflect the consequences of physical stress factors such as UV radiation. This review summarizes the ecotoxicity studies using euglenoid flagellates as model species and their potential to contribute toward rapid screening of ecological impacts of pollution in the aquatic environment. Factors determining the reliability of Euglena tests are outlined.