water flea

American

noun

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

water flea British

noun

any of numerous minute freshwater branchiopod crustaceans of the order Cladocera, which swim by means of hairy branched antennae See 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

Etymology

Origin of water flea

First recorded in 1575–85

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

water flea

But evidence of the potential effects of PVA “are scarce,” said Magni, who co-authored a study that did not find toxic effects associated with the compound in fish embryos and a species of water flea.

From Washington Post ● Nov. 15, 2022

This week Hintz published a new paper focusing on the fate of the water flea, a tiny critter that tends to thrive in such large numbers that it has a key influence on ecosystem health.

From Scientific American ● Dec. 6, 2018

That testing involves students helping to constantly breed fathead minnows and Ceriodaphnia dubia, a species of water flea that is used in testing water quality.

From Washington Times ● Sep. 11, 2017

The water flea has seen its genetics change over just a few decades to respond to higher water temperatures.

From The Guardian ● Apr. 5, 2017

A little water flea was described as a separate genus, Nauplius, before it was known to be the larva of a higher water flea, and so also Leptus was thought to be a mature mite.

From Our Common Insects A Popular Account of the Insects of Our Fields, Forests, Gardens and Houses by Packard, A. S. (Alpheus Spring)

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023