Daphnia

[daf-nee-uh] /ˈdæf ni ə/
noun
1.
a genus of tiny, freshwater crustaceans having a transparent body, used in biological research and as food for tropical fish.
Compare water flea.
Origin
1840-50; < Neo-Latin, perhaps after Daphne; see -ia
British Dictionary definitions for Daphnia

daphnia

/ˈdæfnɪə/
noun
1.
any water flea of the genus Daphnia, having a rounded body enclosed in a transparent shell and bearing branched swimming antennae
Word Origin
C19: from New Latin, probably from Daphne