The freshwater crustacean Daphnia (IMAGE) Marine Biological Laboratory Caption The freshwater crustacean Daphnia (water flea) is a common research organism in ecology, toxicology, evolutionary developmental biology, and other fields. Credit Proyecto Agua Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. Adaptations must be shared under the same terms. License CC BY-NC-SA 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.