water flea

American  

noun

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

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water flea British  

noun

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

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Etymology

Origin of water flea

First recorded in 1575–85

Example Sentences

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)