A marimo ball is a rare growth form of algae, which grows into large green balls with a soft, velvety appearance.they are native to japan where they naturally grow at Lake Akan. They are also found in Iceland ,Estonia and scotland. They can grow patches on a lake floor at depths from 2 to 2.5 m. The round shape of the marimo is maintained by wave action that turns it. In Japan the marimo has said to be a national treasure. They where named by the Japanese botanist “Tatsuhiko Kawakami”. Mari means bouncy ball and Mo is a term for plants that grow in water. So , marimo means bouncy plant.People often mistake them for living animals because they are usually moving around in the tank.