plankton

American  

[plangk-tuhn] / ˈplæŋk tən /

noun

1. the aggregate of passively floating, drifting, or somewhat motile organisms occurring in a body of water, primarily comprising microscopic algae and protozoa.

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plankton British  

/ plæŋkˈtɒnɪk, ˈplæŋktən /

noun

1. the organisms inhabiting the surface layer of a sea or lake, consisting of small drifting plants and animals, such as diatoms Compare nekton

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plankton Scientific  

/ plăngk′tən /

1. Small organisms that float or drift in great numbers in bodies of salt or fresh water. Plankton is a primary food source for many animals, and consists of bacteria, protozoans, certain algae, cnidarians, tiny crustaceans such as copepods, and many other organisms.

2. Compare benthos nekton

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Other Word Forms

• planktonic adjective

Etymology

Origin of plankton

1890–95; < German, special use of neuter of Greek planktós drifting, equivalent to plang-, variant stem of plázesthai to drift, roam, wander + -tos verbid suffix

Example Sentences

Many calcareous plankton species that normally sink to the ocean floor disappeared during the extinction event.

From Science Daily • Mar. 15, 2026

The researchers determined that this plankton species evolved between 3.5 and 11 thousand years after the Chicxulub impact, though the exact timing varied depending on the site studied.

From Science Daily • Mar. 15, 2026

By converting nitrogen into different chemical forms in seawater, these microbes regulate the growth of microbial plankton.

From Science Daily • Mar. 11, 2026

The authors call for urgent efforts to measure how much calcium carbonate each plankton group produces, dissolves, and exports to deeper waters.

From Science Daily • Feb. 8, 2026

“SeaSteak? Sure, if you like plankton pressed into meat shapes.”

From "Scythe" by Neal Shusterman