Ceriodaphnia dubia is a species of water flea in the class Branchiopoda, living in freshwater lakes, ponds, and marshes in most of the world. They are small, generally less than in length. Males are smaller than females. C. dubia moves using a powerful set of second antennae, and is used in toxicity testing of wastewater treatment plant effluent water in the United States. Climate change and particularly ultraviolet radiation B may seriously damage C. dubia populations, as they seems to be more sensitive than other cladocerans such as Daphnia pulex or D. pulicaria.
