At the lake bottom. (IMAGE) University of Tokyo Caption The alga Aegagropila linnaei can live as free-floating filaments, grow on rocks, grow into the signature ball shape and form flattened balls when squished, depending on their environment. Ball growth is slow at about 5 millimeters per year and they can live for centuries. Credit 2022 Yoichi Oyama Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.