zoo·​plank·​ton ˌzō-ə-ˈplaŋ(k)-tən How to pronounce zooplankton (audio)
plural zooplankton also zooplanktons
: freely floating or weakly swimming typically minute aquatic protozoans and animals (such as copepods, rotifers, and arrow worms) or the eggs or larvae of aquatic animals (such as anemones, mollusks, and fish) : plankton composed of animals
… numerous varieties of adult gamefish depend on zooplankton for a substantial portion of their diets throughout their lives.Byron W. Dalrymple
Phytoplankton exhale life-giving oxygen and are consumed as food by zooplankton and small fish, which, in turn, are eaten by larger fish.Kenneth R. Weiss
Right whales eat zooplankton, which are tiny creatures that float along in the water column, by straining huge amounts of sea water through their baleen.Wendall Waters
compare phytoplankton
zooplanktonic adjective
zooplanktonic organisms

Examples of zooplankton in a Sentence

Recent Examples on the Web North Pacific right whales are baleen whales, which feed by straining huge volumes of ocean water through their comb-like baleen plates that trap copepods and other zooplankton. Lisa M. Krieger, The Mercury News, 27 May 2024 Or little creatures known as zooplankton gobble up those phytoplankton and poop out pellets of carbon that also sink. Matt Simon, WIRED, 18 Jan. 2024 And then the larger predators like fish that eat the zooplankton will be impacted, on up the food chain. Matt Simon, WIRED, 8 Feb. 2024 According to the researchers, modern arrow worms are smaller predators that survive on meals of tiny zooplankton. Sam Walters, Discover Magazine, 9 Jan. 2024 The cycling of microplastics through the Arctic Ocean may ultimately affect the food chain: The zooplankton that feed on Melosira arctica algae are eating the particles, and when the microplastics sink to the seafloor, bottom-dwelling creatures eat them too. Matt Simon, WIRED, 10 July 2023 Phytoplankton blooms: Less ice and warmer waters can cause phytoplankton − microscopic plant-like organisms that form the base of many aquatic food webs − to bloom earlier than the zooplankton that feed on them. Caitlin Looby, Journal Sentinel, 3 Jan. 2024 If there are no zooplankton around, this could have a ripple effect up the food chain, especially on the fish that depend on zooplankton. Caitlin Looby, Journal Sentinel, 3 Jan. 2024 The hypothesis is that the zooplankton are responding to temperature cues and blooming earlier in the season, before the right whales have an opportunity to forage or feed, Robbins said. Julia Jacobo, ABC News, 13 Sep. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'zooplankton.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


zoo- + plankton

First Known Use

1897, in the meaning defined above

Time Traveler
The first known use of zooplankton was in 1897

Dictionary Entries Near zooplankton

Cite this Entry

“Zooplankton.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/zooplankton. Accessed 24 Jun. 2024.

Kids Definition


zoo·​plank·​ton ˌzō-ə-ˈplaŋ(k)-tən How to pronounce zooplankton (audio)
: plankton that is composed of animals

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