Daphnia

Daphnia Temporal range: Cretaceous–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Daphnia pulex
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Branchiopoda
Subclass:	Phyllopoda
Superorder:	Diplostraca
Order:	Anomopoda
Family:	Daphniidae
Genus:	Daphnia Müller, 1785
Subgenera
Australodaphnia (Colbourne et al., 2006) Ctenodaphnia (Dybowski & Grochowski, 1895) Daphnia (O. F. Müller, 1785)
Diversity
> 200 spp.
Synonyms [1]
Cephaloxus (Sars, 1861) Dactylura (Brady, 1898) Daphniopsis (Sars, 1903) Hyalodaphnia (Schoedler, 1866) Leiodaphnia (Dybowski & Grochowski, 1895)

Daphnia is a genus of small planktonic crustaceans, 0.2–6.0 mm (0.01–0.24 in) in length. Daphnia are members of the order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory swimming style resembles the movements of fleas. Daphnia spp. live in various aquatic environments ranging from acidic swamps to freshwater lakes and ponds.

The two most commonly found species of Daphnia are D. pulex (small and most common) and D. magna (large). They are often associated with a related genus in the order Cladocera: Moina, which is in the Moinidae family instead of the Daphniidae, and is much smaller than D. pulex (roughly half the maximum length).