Sea Slugs and Idotea (IMAGE) University of California - Santa Cruz Caption Both sea slugs and Idotea (the crustacean between the two sea slugs in this photo) feed on algae and increase in numbers when the crab population is controlled by sea otters. Credit Photo by Brent Hughes 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.