<i>Tridacna gigas</i> (IMAGE) National University of Singapore Caption This is the world's largest giant clam species and the most threatened mollusc, according to a recent study led by NUS marine scientists. Credit Neo Mei Lin Usage Restrictions None 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.