Opaque Shells (IMAGE) University of California - San Diego Caption The opaque shells of clusterwink snails would seem to blunt light transmission. Credit Scripps Institution of Oceanography, UC San Diego 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.