Euglena are single-celled organisms that live mostly in fresh water, although a few species do live in salt water. They have long tails called flagella, which they use to move through water. Most species of euglena contain chloroplasts and produce their own food through photosynthesis.
All euglena belong to the genus Euglena and the class Eugelnoidea. They are protists, which means they show characteristics seen in both plants and animals. Although most species do carry out photosynthesis using chlorophyll pigments, they also feed on other organisms by engulfing them in their cell membranes through a process known as phagocytosis. Euglena do not have cell walls, but they do have a special protein layer called a pellicle that surrounds the cell and offers protection.
Euglena reproduce asexually through a process known as binary fission. The process begins when the euglena replicates its DNA and expands in size. Then, it divides in half, creating two complete organisms, each with identical DNA.
Euglena are common in ponds and streams. They cannot be seen with the naked eye, but are easily visualized under a light microscope. Euglena are often identified visually by their red eyespots and the presence of flagella, which they use to detect light.