Medakamo hakoo growing on an agar plate. (IMAGE) University of Tokyo Caption Green lines with dots show a pure culture of Medakamo hakoo streaked onto an agar medium. Study co-author Emeritus Professor Tsuneyoshi Kuroiwa first discovered the algae when the water in his home goldfish tank turned green after he added medaka fish (Japanese rice fish), and he decided to look at samples under his home microscope. However, where the algae originated from - the water, fish or somewhere else - is still unknown. Credit 2023 Sachihiro Matsunaga Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND 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.