Noun water flea has 2 senses
- cyclops, water flea - minute free-swimming freshwater copepod having a large median eye and pear-shaped body and long antennae used in swimming; important in some food chains and as intermediate hosts of parasitic worms that affect man e.g. Guinea worms
--1 is a kind of copepod, copepod crustacean
--1 is a member of genus Cyclops
- daphnia, water flea - minute freshwater crustacean having a round body enclosed in a transparent shell; moves about like a flea by means of hairy branched antennae
--2 is a kind of branchiopod crustacean, branchiopod, branchiopodan
--2 is a member of genus Daphnia
,