plankton
noun
plank·ton
ˈplaŋ(k)-tən 
-ˌtän
plural plankton also planktons
: the passively floating or weakly swimming usually minute organisms (such as dinoflagellates, diatoms, copepods, radiolarians, and larval crustaceans and fish) of a body of water
Note: An individual organism found in plankton is technically referred to as a plankter.
… photosynthesizing plankton will grow at their intrinsic rates until nutrients become limiting, light is reduced by shading, and grazing organisms become abundant enough to check the increase …—
W. H. Berger
W. H. BergerAlmost all marine invertebrates, such as corals, clams, and starfish, reproduce by releasing microscopic larvae that drift in the plankton for a period ranging from minutes to months.—Randy Olson et al.
Randy Olson et al.Dense schools of menhaden … pour through these waters, toothless mouths … slurping up plankton and detritus …—H. Bruce Franklin
H. Bruce FranklinThe prolific zebra mussels have extremely efficient filtering systems, removing enormous quantities of plankton from the water …—Nelson Bryant
see also phytoplankton, zooplankton
Nelson Bryant
planktonic
adjective
Other planktonic forms are grazers—tiny animals that filter algae and other organic matter out of the water and consume it.
—Wyoming Wildlife
Wyoming Wildlife
Examples of plankton in a Sentence
fish that feed mainly on plankton
Recent Examples on the Web
But the method becomes more challenging when the water is not as clear, thanks to factors such as sediment or plankton, or the seafloor is not bright—perhaps because it is covered by grass.
—Newsweek, 4 Nov. 2024
Unique to this species is a white band of denticles across its upper jaw, which researchers believe could reflect bioluminescent light from deep-sea plankton, potentially attracting prey in the dark waters where these sharks often roam.
—Melissa Cristina Marquez, Forbes, 31 Oct. 2024
Microscopic plankton are at the heart of the ocean’s food chain, feeding much bigger animals like whales.
—Laura Baisas, Popular Science, 17 Oct. 2024
Invasive mussels are filter-feeders, sucking out nutrients and plankton that native species rely on for food.
—Caitlin Looby, Journal Sentinel, 12 Sep. 2024
See all Example Sentences for plankton 
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Newsweek, 4 Nov. 2024
Unique to this species is a white band of denticles across its upper jaw, which researchers believe could reflect bioluminescent light from deep-sea plankton, potentially attracting prey in the dark waters where these sharks often roam.
—Melissa Cristina Marquez, Forbes, 31 Oct. 2024
Microscopic plankton are at the heart of the ocean’s food chain, feeding much bigger animals like whales.
—Laura Baisas, Popular Science, 17 Oct. 2024
Invasive mussels are filter-feeders, sucking out nutrients and plankton that native species rely on for food.
—Caitlin Looby, Journal Sentinel, 12 Sep. 2024
See all Example Sentences for plankton
Dictionary Entries Near plankton
Cite this Entry
“Plankton.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/plankton. Accessed 22 Nov. 2024.
Copy CitationKids Definition
plankton
noun
plank·ton
ˈplaŋ(k)-tən
-ˌtän
: the floating or weakly swimming animal and plant life of a body of water
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