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Diatoms and Dinoflagellates

Diatoms and Dinoflagellates. Lecture 11. Fan-Shaped Phylogenetic Tree. “Phytoplankton”. Unicells Filamentous Colonies – chains, or spheres. Algal pigments. Cocco, Dino, Diatom Overview. “Shell”, “Wood”, or “Glass” Houses armor the cell and protect from predation/environ

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Diatoms and Dinoflagellates

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  1. Diatoms and Dinoflagellates Lecture 11

  2. Fan-Shaped Phylogenetic Tree

  3. “Phytoplankton” • Unicells • Filamentous • Colonies – chains, or spheres

  4. Algal pigments

  5. Cocco, Dino, Diatom Overview • “Shell”, “Wood”, or “Glass” Houses armor the cell and protect from predation/environ • Coccos are small open ocean • Dinos are warmer waters/summer • Diatoms are cooler waters/winter • Diatoms are the “grass of the sea and the estuary”

  6. Coccolithophores • Division Haptophyta = Prymnesiophyta • 500 spp extant, many more fossil spp • 0.2 – 2 mm diameter (pico – nanno) • Biflagellate or coccoid unicells • Cell wall of calcareous scales • Chl a + c; carotenoids • Warm and tropical • Emiliania huxleyi

  7. B. = coccolithophores “shell” house • Very small cells (2-20um) • Calcified scales armor cell Major group of open ocean phytoplankton http://oceanography.tamu.edu/Quarterdeck/QD5.2/qdhome-5.2.html

  8. Some Coccolithophores Prymnesiales Isochrysidales Coccosphaerales Pavlovales

  9. Calcidiscus Emiliania huxleyi Pontosphaera

  10. Diatoms • Division Heterokontophyta, Class Bacillariophyceae • 1400-1800 spp marine, >100’000 spp total • 2um-2mm (nanno - netplankton) • Unicellular, often in colonies • Cell wall siliceous • Chl a, c, B-carotene, fucoxanthin, diatoxanthin, diadinoxanthin • Centric (plankton) vs Pennate (benthic, epiphytic) • Temperate and cold waters

  11. Ecological roles • Marine phytoplankton • Periphyton (aufwuchs) • Grow on plants (epiphytes), rocks (epilithic), sand grains (epipelic), or on sediments (epipsammic) • “grass of the sea” – 20-25% of global primary production. • REQUIRE SILICON • Well represented in fossil record – “diatomaceous earth”

  12. Falkowski & Raven 2007

  13. Cell wall & reproduction • Frustule – upper epitheca, lower hypotheca • Girdle divides the two thecae • Bilateral, radial, or irregular symmetry • Asex cell division: parental theca is new epitheca, results in succesive size reduction of 1 of the 2 daughter lines. • Size increase by swelling after sex. gamete production -> auxospore (resting cyst). Happens when cell <1/3 of original size.

  14. Pleurosigma BENTHIC CELLS – NEAR SHORE OCEANIC CELLS – OFF SHORE Diatoms are extremely important primary producers:“grass of the sea”!

  15. Or Centrales (=Biddulphiales) • Centric diatoms – “planktonic” • 3 suborders: • Coscinodiscineae (8 families): Thalassiosira, Skeletonema, Melosira, Coscinodiscus • Rhizosoleniineae (1 family): Rhizosolenia, Pseudosolenia • Biddulphiineae (5 families): Chaetoceras, Lithodesmium, Odontella

  16. Melosira Thalassiosira Skeletonema Cyclotella Actinoptychus Chaetoceras

  17. Or Pennales (=Bacillariales) • Pennate diatoms – “benthic” • Raphe = fissure along apical axis. Used for locomotion; cytoplasm acts as a belt moving cell forward. • 2 suborders: • Fragilariineae – araphid (4 families): Striatella, Fragilaria, Thalassionema, Thalassiothrix • Bacillarineae – raphid (4 families): Navicula, Bacillaria, Nitzschia, Pseudo-nitzschia http://www.dnr.state.md.us/bay/cblife/algae/diatom/index.html

  18. Pseudo-nitzschia Raphoneis Cylindrotheca Thalassionema Asterionellopsis

  19. EpiphyticPennateDiatoms

  20. Sullivan, MJ, CA Montcreiff, AE Daehnick 1991. Primary Production Dynamics of Epiphytic Algae in Mississippi Seagrass Beds. MASGC-91-009 Sullivan, MJ, CA Montcreiff 1993. Trophic Importance of Epiphytic Algae in Mississippi Seagrass Beds. MASGP-92-018 Sullivan, MJ, DJ Wear 1996. Effects of Water-Column Enrichment on the Production Dynamics of 3 Seagrass Species and their Epiphytic Algae. MASGP-93-023

  21. Sawgrass Diatoms Mangrove Diatoms http://serc.fiu.edu/periphyton/

  22. Dinoflagellates • Division Pyrrhophyta = Dinophyta • 2000 spp • Sizes: 10um-1mm • Biflagellate unicellular, some filaments • Cell has thecal plates (upper & lower) • Chl a, c; B-carotene, peridinin, diadinoxanthin, fucoxanthin, diatoxanthin • Red tides (HABs); ciguatera • Pfisteria hysteria… • Zooxanthellae in Corals/Anemones • Warmer seas and/or summer blooms

  23. Ecological roles • Oceanic and estuarine phytoplankton • Protists that “captured” brown algal symbionts • Autotrophs, auxotrophs (req vitamins), heterotrophs (>50% spp)! -> phageotrophic (ingest organisms) and parasitic (feed off host) • Produce potent neurotoxins: Red tides, ciguatera, paralytic shellfish poisoning (PSP) • Zooxanthellae symbiotic in corals, jellyfish, protists (forams, ciliates, radiolarians)

  24. Flagellae and Cell walls • Desmokont = 2 anterior flagellae • Dinokont = 2 flagellae in grooves – transverse tinsel flagellum in cingulum, posterior flagellum in sulcus. • Move in forward corkscrew motion at 1-2m hr-1 • Upper epitheca, lower hypotheca. Shedding of theca = ecdysis. Regrows second half of same size (no decreasing size series). • Theca of polysaccharide plates (cellulose, mannose, galactose) and membranes.

  25. C. Prorocentrum minimum Dinokont cell Desmokont cell

  26. Steidinger (1997) 13 orders: Prorocentrales Dinophysiales Gymnodiniales Suessiales Ptychodiscales Noctilucales Lophodiniales Brachydiniales Gonyaulacales Peridiniales Blastodiniales Syndiniales Phytodiniales Van den Hoek (1995) 12 orders: Gymnodiniales Gloeodiniales Thoracosphaerales Phytodiniales Dinotrichales Dinameobidales Noctilucales Blastodiniales Syndiniales Peridiniales Dinophysiales Prorocentrales Taxonomy of Dinos 8 of 12/13 orders are same

  27. Unarmored dinokont cell with distinct cingulum and sulcus. 3 families: Gymnodinium (200+spp), Polykrikos (5spp),Warnowia (25 spp) Order Gymnodiniales

  28. Coccoid cells living as symbionts. Thinly armored, transitional between “naked” and armoured cells 1 fossil + 1 extant family: Symbiodinium (25spp) S. microadriaticum Order Suessiales (Gymnodiniales)

  29. Free-living amoeboid stage alternates with non-motile coccoid stage. Dinamoebidium Pfisteria Order Dinamoebidales

  30. Large free-living unarmored cells, many vacuoles, flagella reduced or absent 3 families: Kofoidinium (5 spp), Leptodiscus (5 spp),Noctiluca (1 sp) Order Noctilucales http://dinos.anesc.u-tokyo.ac.jp/plankton/list.htm

  31. Armored dinokonts or varied form. Plate tabulation is diagnostic. May include Or Gonyaulacales Protoperidinium (250 spp), Ceratium (125 spp), Gonyaulax (100 spp), Gambierdiscus toxicus Order Peridiniales

  32. Laterally flattened cells with dinokont flagellar orientation and premedian cingulum. 3 families: Amphisolenia (50spp), Dinophysis (100spp),Phalacroma (100 spp) Order Dinophysales

  33. Armored, biflagellate cells with desmokont (anterior) flagellar insertion. No cingulum or sulcus 1 family: Prorocentrum(50spp), Mesoporos (10spp) Order Prorocentrales

  34. Dino life cycles

  35. Toxic Marine Dinos • Only about 60 of 2000 species • Most are photosynthetic estuarine/neritic (near shore) forms • Probably produce benthic, sexual resting stages (cysts) • Capable of producing blooms or single spp – exclude other plankton • Bioactive water- or lipid-soluble chemicals that are cytolytic, hemolytic, hepatotoxic, or neurotoxic

  36. GoM K. brevis monitoring September 12, 1995 at North Lido Beach http://isurus.mote.org/~pederson/phyto_ecol.phtml

  37. http://www.cop.noaa.gov/stressors/extremeevents/hab/welcome.htmlhttp://www.cop.noaa.gov/stressors/extremeevents/hab/welcome.html http://www.ncddc.noaa.gov/habsos/Mapping/

  38. Harmful Algal Blooms (HAB) • Blooms of marine algae which produce: • Toxic effects to organisms (and humans) • Physical impairment of fish/shellfish • Nuisance conditions from odor, discoloration • Severe oxygen depletion or benthic overgrowth • GEOHAB and ECOHAB programs http://www.cop.noaa.gov/stressors/extremeevents/hab/current/fact-ecohab.html

  39. Phytoplankton Monitoring Network • http://www.chbr.noaa.gov/PMN/index.htm • Sample every 2 weeks using a 20um net for 3 minutes. • Identify cells at 100x under microscope • Record number in approx 1ml sample on gridded microscope slide. • Enter data to online database.

  40. Dinoflagellates Diatoms

  41. http://www.whoi.edu/page.do?pid=11913&tid=282&cid=40526

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