water flea

noun

any of various small crustaceans that move about in the water like fleas, as those of the genus Daphnia.

Origin of water flea

First recorded in 1575–85

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for water flea

Historical Examples of water flea

In short, she was a branchiopod, to be vulgarly precise, a water-flea.
"Wee Tim'rous Beasties"
Douglas English
I have already spoken of the fresh-water shrimp and the water-flea (Daphnia pulex).
Amateur Fish Culture
Charles Edward Walker
The water-flea, Daphnia (a crustacean), lays two kinds of eggs known as “summer” and “winter” eggs.
Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 1
Various

British Dictionary definitions for water flea

water flea

noun

any of numerous minute freshwater branchiopod crustaceans of the order Cladocera, which swim by means of hairy branched antennaeSee also daphnia

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012