[fahy-tuh-plangk-tuh n]
Compare zooplankton.

Origin of phytoplankton

First recorded in 1895–1900; phyto- + plankton Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for phytoplankton


  1. the photosynthesizing organisms in plankton, mainly unicellular algae and cyanobacteriaCompare zooplankton
Derived Formsphytoplanktonic (ˌfaɪtəplæŋkˈtɒnɪk), adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for phytoplankton

1897, from phyto- + plankton.

Online Etymology Dictionary, © 2010 Douglas Harper

phytoplankton in Science


  1. Plankton consisting of free-floating algae, protists, and cyanobacteria. Phytoplankton form the beginning of the food chain for aquatic animals and fix large amounts of carbon, which would otherwise be released as carbon dioxide.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.