A Daphnia (IMAGE) U.S. National Science Foundation Caption The tiny water flea Daphnia has the most genes of any animal, some 31,000. Credit Paul Hebert, University of Guelph 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.