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Ecological Role of Protists. Casey Sullivan, Aliah Marzolf, Natalie Minor, Stefani Williams, Max Rossa. Groups of Protists. Protozoa Use phagocytosis to ingest prey Algal Use photosynthesis to produce energy Can be mixotrophic Fungi
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Ecological Role of Protists Casey Sullivan, Aliah Marzolf, Natalie Minor, Stefani Williams, Max Rossa
Groups of Protists • Protozoa • Use phagocytosis to ingest prey • Algal • Use photosynthesis to produce energy • Can be mixotrophic • Fungi • Use phagocytosis to ingest bacteria and absorb nutrients from environment
Protozoa • Phagotrophic • Mouth-like structures • Pseudopodia • Heterotrophic dinoflagellates • Novel predator-prey relationships • Prey on phytoplankton, copepod eggs, etc. • Act as prey for some metazoa • Some predators are prey for other heterotrophic dinoflagellates
Algal • Photosynthetic • Some mixotrophic (dinoflagellates and chrysomonads) • mixotrophic: balances photosynthesis and phagocytosis • Use both photosynthesis and phagocytosis • In marine and freshwater environments • Grouped into divisions based on pigments
Fungal • Phagotrophic • Slime Molds • Amoeboid Movement • Ingest bacteria • Live in decayed wood • Often brightly colored
RED TIDE Gymnodinium breve *Red tide is a microscopic protist that secretes a potent neurotoxin which contaminates oceans and especially coastal environments. *These toxins are deadly to aquatic life, as filter feeding organisms consume these toxins, causing it to become concentrated in the vital organs, causing death *These protists also cause irritation in humans, but exposure is not life-threatening. However, any fish or shellfish contaminated with Red Tide can be very harmful if consumed. http://serc.carleton.edu/images/microbelife/topics/red_tide_genera.v3.jpg
Protists and Dangerous Bacteria *E.coli is a bacteria that can cause extreme illness, and is one that is being found in lakes and creeks. Protists can be used to help fight off the E.coli bacteria by eating it. *One strain of this bacteria produces a toxin called Shinga that can cause illness in people *This strain of E.coli does very well because the Shinga toxin fights off aquatic protists that would otherwise eat the bacteria and help keep it in control
References • Jeong, H. J. (1999). The ecological roles of heterotrophic dinoflagellates in marine planktonic community. The Journal of Eukaryotic Microbiology, 46(4), 390-396. • Mauro, Stephen A.; Opalko, Hannah; Lindsay, Kyle; Colon, Michael P. & Koudelka, Gerald B. (2013). The microcosm mediates the persistence of Shiga toxin producing E. coli (STEC) in freshwater ecosystems. Applied and Environmental Microbiology, 79, gdg doi: 10.1128 • Sanders, R. W. (1991). Mixotrophic protists in marine and freshwater ecosystems. The Journal of Eukaryotic Microbiology, 38(1), 76-81. • http://biology.clc.uc.edu/courses/bio106/protista.htm • http://www.atlanticbreezes.com/aquatic/aquatichealth/redtides.htm • http://triemerlab.plantbiology.msu.edu/Euglena/Index.htm