Differential interference contrast light micrograph of two genus of green algae. Pandorina sp. (right) and Eudorina sp. (left). They are microscopic green algae living in colonies and swim/rotate using flagella. The red dots are eye spots to allow them to swim towards the light. The colony is surrounded by a translucent mucilage. Magnification: x600 when printed at 10 centimetres wide at its longest edge.