Dartmouth Didymo Study (IMAGE) Dartmouth College Caption This is the freshwater algae known as "rock snot" or "didymo." Credit Carole-Anne Gillis Usage Restrictions Credit Carole-Anne Gillis 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.