Definition of plankton in US English:



  • The small and microscopic organisms drifting or floating in the sea or fresh water, consisting chiefly of diatoms, protozoans, small crustaceans, and the eggs and larval stages of larger animals. Many animals are adapted to feed on plankton, especially by filtering the water.

    ‘prawns change their diet from plant plankton to animal plankton’
    Compare with nekton
    as modifier ‘plankton feeders’
    • ‘Manta rays live in tropical waters and feed on plankton, using their frontal flaps.’
    • ‘The significance of this is that other species such as shellfish and crustaceans feeding in plankton could be affected.’
    • ‘The eggs and young, which hatch in around two weeks, drift in the Oceans currents feeding upon plankton for the first few months of their life.’
    • ‘Microscopic plankton trapped in the finely tipped gills are pulled slowly into waiting mouths.’
    • ‘The young remain in the water column feeding on plankton until they are around 50 mm in length.’
    • ‘Every March and April, whale sharks come to Ningaloo Reef on Australia's outback coast to feed on plankton.’
    • ‘The expedition also found rings of plankton organisms that measured 10 km wide.’
    • ‘The plankton that permeates these waters attracts vast swarms of anchovies, which in turn draw millions of seabirds.’
    • ‘Whales eat big fish, which eat medium fish, which eat small fish, which eat smaller fish, which eat plankton.’
    • ‘Each oyster feeds naturally on plankton brought in on the tide until the time comes for them to be lifted, washed and packed.’
    • ‘They may also forage for insects, plankton, mollusks, crustaceans, and small fish.’
    • ‘The production of plankton is directly related to the fertility of the water.’
    • ‘The dung feeds microscopic plankton, which are consumed by worms and larvae.’
    • ‘Smaller warm water plankton has replaced them and they are less nutritious, according to the scientists.’
    • ‘Scientists say that the change in species of plankton, from cold water types to warm water, are less favourable to cod in its juvenile stage.’
    • ‘In the newly exposed waters and throughout the North Atlantic Ocean, plankton growth is prodigious.’
    • ‘They have no teeth, and feed by ‘hoovering up’ tiny plankton from the sea.’
    • ‘All plankton, kelp forests and seagrass beds are found in the euphotic zone.’
    • ‘However, the seaweeds or the algae and in particularly the microscopic plankton can fix a lot more carbon than a forest can.’
    • ‘These regions of high productivity promote the development of plankton, which feeds planktivorous fish such as anchovies.’
    • ‘The fish then turn to feeding on larger plankton, including small fish, before migrating down into the depths at around two years of age.’


Late 19th century: from German, from Greek planktos ‘wandering’, from the base of plazein ‘wander’.