title: Mixotrophy in the Marine Plankton.
abstract: Mixotrophs are important components of the bacterioplankton, phytoplankton, microzooplankton, and (sometimes) zooplankton in coastal and oceanic waters. Bacterivory among the phytoplankton may be important for alleviating inorganic nutrient stress and may increase primary production in oligotrophic waters. Mixotrophic phytoflagellates and dinoflagellates are often dominant components of the plankton during seasonal stratification. Many of the microzooplankton grazers, including ciliates and Rhizaria, are mixotrophic owing to their retention of functional algal organelles or maintenance of algal endosymbionts. Phototrophy among the microzooplankton may increase gross growth efficiency and carbon transfer through the microzooplankton to higher trophic levels. Characteristic assemblages of mixotrophs are associated with warm, temperate, and cold seas and with stratification, fronts, and upwelling zones. Modeling has indicated that mixotrophy has a profound impact on marine planktonic ecosystems and may enhance primary production, biomass transfer to higher trophic levels, and the functioning of the biological carbon pump.
authors.affiliation: Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, Maryland 21613; email: stoecker@umces.edu.
authors.forename: Diane K
authors.initials: DK
authors.lastname: Stoecker
authors.affiliation: Marine Biological Section, Department of Biology, University of Copenhagen, 3000 Helsingør, Denmark; email: pjhansen@bio.ku.dk.
authors.forename: Per Juel
authors.initials: PJ
authors.lastname: Hansen
authors.affiliation: Department of Biological Sciences, University of Southern California, Los Angeles, California 90089-0371; email: dcaron@usc.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Caron
authors.affiliation: Department of Biosciences, Swansea University, Swansea SA2 8PP, United Kingdom; email: a.mitra@swansea.ac.uk.
authors.forename: Aditee
authors.initials: A
authors.lastname: Mitra
mesh_terms: D000818:Animals; D017753:Ecosystem; D009792:Oceans and Seas; D010788:Photosynthesis; D010839:Phytoplankton; D010933:Plankton; D015048:Zooplankton
keywords: chloroplast-retaining ciliates; mixotrophic dinoflagellates; phagotrophic phytoflagellates; photoheterotrophy; rhizarian symbioses