Unionid mussel, Pronodularia japanensis (IMAGE) Ehime University Caption Freshwater unionid species endemic in Japan. Credit Hiroki Hata (Ehime University) Usage Restrictions Please get copyright permission License Licensed content 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.