Euglena is a genus of single-celled eukaryotic organisms found in stagnant freshwater such as ponds and lakes, forming a visible green (or sometimes red) scum on the surface. When scientists refer to Euglena, they're often talking about the model species Euglena gracilis.

Does euglena live in freshwater?

Found worldwide, Euglena live in fresh and brackish water rich in organic matter and can also be found in moist soils.

What is the habit and habitat of euglena?

Euglena live in fresh and brackish water habitats rich in organic matter. Some species develop tremendous populations as green or red "blooms" in ponds or lakes.