<i>Dreissena polymorpha</i> (IMAGE) Pensoft Publishers Caption These are invasive zebra mussels (Dreissena polymorpha) on a rock collected in the Hudson River, NY, USA. Credit Heather Malcom Usage Restrictions Creative Commons Attribution 3.0 License 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.