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Marine Heterotrophic Protists

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Marine Heterotrophic Protists MARINE HETEROTROPHIC PROTISTS Eukaryote groups highlighting marine bacterivorous groups heterotrophic mixed Keeling et al. 2005 Trends in Ecology and Evolution vol 20 p.670-676 PROTISTAN PREDATORS • Flagellates (pico, nano, micro) • Ciliates (micro) • Amoeboid (nano to macro) • Phaeodaria silica skeleton • Acantharea strontium sulfate • Foraminifera (1 mm) calcium carbonate shell HETEROTROPHIC PICOEUKARYOTES 0.2 - 2 µm Mastigonemes 0.5 µm Symbiomonas scintillans (Roscoff Plankton Group) 1 µm Picophagus flagellatus (Roscoff Plankton Group) HETEROTROPHIC NANOFLAGELLATES “HNAN” 2 - 20 µm Cafeteria roenbergensis (Bicosoecids) Massisteria marina D. J. Patterson D. J. Patterson Patterson & Fenchel 1990 MEPS 62: 1-19 Tamara Clarke Heterokonts HETEROTROPHIC NANOFLAGELLATES “HNAN” 2 - 20 µm Bodo saltans Paraphysomonas imperforata (Chrysomonad) (Bodonid) Siliceous scales 2 µm 0.5 µm D. J. Patterson Heterokonts HETEROTROPHIC NANOFLAGELLATES Choanoflagellates are closest Monosiga (Choanoflagellate) protistan relative to animals 2 µm 1 µm 1 µm 5 µm 2 µm 2 µm Unikonts MICROZOOPLANKTON (20-200 µm) CILIATES 5 µm 20 µm Dictyocysta mitra Strombidium inclinatum Laboea strobila Fabrea salina (J. Dolan) (Modeo et al. 2003 J. Euk. (Agatha et al. 2004 (Photoreception and Microbiol.) J. Euk. Microbiol.) sensory transduction group - Pisa) Tintinnid Oligotrich Heterotrich MICROZOOPLANKTON (20-200 µm) CILIATES HJ Clark 1866 Am J Sci Picture by Gerd Gunther, courtesy 2008 Olympus http://fishparasite.fs.a.u-tokyo.ac.jp/Trichodina/Trichodina.html BioScapes Digital Imaging Competition Trichodina spp. Peritrichia Collected at: http://skepticwonder.fieldofscience.com/2010_06_01_archive.html MICROZOOPLANKTON (20-200 µm) DINOFLAGELLATES • Some are very small and classified as nanoflagellates • Most are microplankton (>20 µm) • Some heterotrophic, some autotrophic, or mixotrophic • May be armored (cellulosic thecal plates) or naked • Many bizarre shapes and one huge one up to 2 mm! • Many bioluminescent MICROZOOPLANKTON DINOFLAGELLATES 40 to 60% of described species non-pigmented Many with pigments are mixotrophic Gyrodinium (Sherr & Sherr) Noctiluca scintillans Gyrodinium uncatenum MICROZOOPLANKTON Amoeboid Protists in the Rhizaria Acantharea Phaeodaria Bernd Walz http://www.microscopyu.com/staticgallery/smallworld/2008/id2008-walz.html Shells of silica or strontium sulfate Robert Brons MICROZOOPLANKTON Amoeboid Protists in the Rhizaria Foraminifera Globigerinella Calcium carbonate shell PROTIST FEEDING MODES •Filter •Raptorial •Diffusive BEHAVIORAL VARIABILITY FLAGELLATE FEEDING Interception Filter Raptorial Boenigk & Arndt 2002 after Zhukov 1993 FLAGELLATE FEEDING CURRENTS 1 µm mastigonemes 1 µm Monosiga sp. Pseudobobo tremulans PROTIST FEEDING • No Mouth - Ingest particles mostly by phagocytosis. What do they eat? -bacteria -phytoplankton -zooplanton • Digest particles in food vacuole inside the cell (in some cases, outside the cell) Phagocytosis Heterotrophic Prey Protist Digestive vacuoles http://mcbi.ouhsc.edu/clarkelab/phagocytosis_movies/Clarke_Movie1.mov Dinoflagellate Feeding Modes Phagocytosis Peduncle Pallium Prey Handling MIXOTROPHY • There is spectrum of capabilities for photosynthesis among protists that consume prey. • Some are permanent, obligatory • Some persistent • Some are transient MIXOTROPHIC FLAGELLATES Micromonas pusilla (Prasinophyte) Prymnesium (Prymnesiophyte) 1 µm Thomas, C.R. (ed.) (1997) KLEPTOPLASTY BY A FORAM KLEPTOPLASTY Text Myrionecta rubra A ciliate steals chloroplasts from its prey ( a cryptomonad) Geminigera cryophila Serial Kleptoplasty!.
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