Water Flea (Daphnia)

Water fleas (more commonly known as Daphnia) are microscopic crustaceans, belonging to the order Cladocera, that populate the quiet waters of lakes and ponds throughout the world. Most species are found in freshwater habitats, but a few occur in marine environments. Daphnia has a discrete head bearing antennae and a bivalve carapace that encloses all or most of the trunk and abdomen.