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DOMAIN Groups (Kingdom) Dinophyta, Haptophyta, Bacillariophyceae & 1.Bacteria- cyanobacteria (blue green algae) Coscinodiscophyceae 2.Archae 3.Eukaryotes 1. Alveolates- dinoflagellates, coccolithophore Chromista 2. Stramenopiles- diatoms, heterokonyophyta 3. Rhizaria- unicellular amoeboids 4. Excavates- unicellular flagellates 5. Plantae- rhodophyta, chlorophyta, seagrasses 6. Amoebozoans- slimemolds 7. Fungi- heterotrophs with extracellular digestion 8. Choanoflagellates- unicellular 9. Animals- multicellular heterotrophs Phytoplankton 1 2 DOMAIN Eukaryotes Domain Eukaryotes – have a nucei Group Alveolates- 4,000 spp. Chromista = 17,500 spp. chloroplasts derived from red algae Division Haptophyta- 576 spp. coccolithophore contains Alveolates & Stramenopiles according to Algaebase Group Alveolates- 4,000 spp. unicellular,plasma membrane supported by flattened vesicles Division Haptophyta- 576 spp. coccolithophore Division Dinophyta- 3051 spp. of dinoflagellates Group Stramenopiles- 13,500 spp two unequal flagella, chloroplasts 4 membranes Division Heterokontophyta- 13, 235 spp. diatoms & brown algae Class Phaeophyceae- 1836 spp. of brown algae Class Bacillariophyceae- 7249 spp. of pennate diatoms Class Coscinodiscophyceae- 1717 spp. of centric diatoms sphere of stone 3 4 1 Division Haptophyta: Coccolithophore Division Haptophyta: Coccolithophore • Pigments? Autotrophic, Phagotrophic & Osmotrophic (uptake of nutrients by osmosis) •Carbon Storage? Primary producers in polar, subpolar, temperate & tropical waters Coccoliths- external body scales made of calcium carbonate • Chloroplasts? - keep out bacteria & viruses - predatory defense - focus light into cells & nutrient uptake •Flagella? Haptonema- thread like extension involved in prey capture •Life History? - Phagotrophic lack coccoliths and have haptonema 5 6 Haptophyta & Global Biochemistry Division Haptophyta- coccolithophore Genera: Emiliania •Carbon & sulfer cyclingglobal climate •Smallest unicellular eukaryote •Ubiquitous throughout top 200m •Tremendous blooms •Ocean floor limestone accumulation -largest long term sink of inorganic carbon •Armored coating makes the surface more reflective •Cools deeper ocean water •25% of total carbon to deep ocean from coccoliths •Contributes to global warming bc metabolism increases the amount of dissolved CO2 in the water •Produce large amounts of Dimethylsulfide (DMS) & reflect light - Increase acid rain - Enhance cloud formation – sulfate aerosols - Cooling influence on climate 7 8 2 Domain Eukaryotes – have a nuclei Division Dinophyta: Dinoflagellates Group Alveolates- 4,000 spp. Division Dinophyta- 3051 spp. of dinoflagellates • Pigments? •Carbon Storage? • Chloroplasts? whirling flagella •Flagella? Pyrrhos = “fire” bioluminescent •Life History? 9 10 Xanthophyll Peridinin Division Dinophyta - a light harvesting carotenoid - unique in its high ratio of peridinin to chlorophyll 8:2 • Can be heterotrophic (eats food) or autotrophic (makes own food), - makes red tides red or both! •Obligate heterotrophs- secondary loss of plastids • Use flagella to capture prey • All have trichocysts, protein rods that can be ejected, exact function is unknown •Mucocysts- simple sacs that release mucilage 11 12 3 Dinophyta Life History Dinophyta Morphology Haplontic: 1N thallus, the zygote is the only diploid stage • Posses two unequal flagella (at right angles to each other) • Cell wall made up of cellulose plates (a carbohydrate) • Both flagella are hairy (not mastigonemes) Normal conditions: Asexual Tranverse undulipodium (flagellum) Stressful conditions: Fuse with another dinophyta to form hypnozygote (resilient resting stage) Longitudinal undulipodium (flagellum) 13 14 Dinophyta Morphology Dinophyta Movement -Genus determined by number & arrangement of thecal plates • Have a slight capacity to move into more favorable areas to increase productivity Apical Pore Thecal Plates • Use flagella to move (Cellulose) Epicone • Longitudinal flagellum propels in the opposite direction Girdle or Cingulum • Transverse flagellum this flagella allows for turning and Transverse maneuvering Undulipodium Hypocone • Some dinoflagellates (<5%) have eyespots that allow detection of Trichocyst Pores light source (mostly fresh water) Sulcul Groove Longitudinal • Trichocysts??? Undulipodium 15 16 4 Spines Dinophyta Genera: Gymnodinium, Noctiluca, Symbiodinium • Larger SA/V • Helps to stay suspended in water column • Causes red tides when in high concentrations • Produces brevetoxin, a type of neurotoxin. • Poisons humans who eat shellfish that have been filtering it. 17 18 Dinophyta Bioluminescense Genera: Gymnodinium, Noctiluca, Symbiodinium • Ancient mariners thought “the burning seas” were of supernatural origin • Obligate heterotroph • The next hypotheses were that the light was emitted from salt • Bioluminescent! molecules or burning phosphorous • Large – up to 2mm • In 1830, scientists agreed it was biological in origin • Dinophyta are the primary contributors to bioluminescence in the marine habitat • In bioluminescence, energy from an exergonic (spontaneous; energy released) chemical reaction is transformed into light energy • Compound responsible is luciferin (term for general class of 19 compounds) which is oxidized and results in the emission of light20 5 Domain Eukaryotes – have a nuclei Group Stramenopiles- 13,500 spp Dinophyta Division Heterokontophyta- 13, 235 spp. Genera: Gymnodinium, Noctiluca, Symbiodinium Class Bacillariophyceae - 7249 spp. pennate diatoms Class Coscinodiscophyceae -1717 spp. centric diatoms • zooxanthella • endosymbiont of corals, anemones, foraminiferans and radiolarians • provides host with up to 90% of energy requirements 21 22 Class Coscinodiscophyceae Class Bacillariophyceae & Coscinodiscophyceae : Diatoms • Pigments? Class Bacillariophyceae •Carbon storage? • Chloroplasts? • Flagella? • Life History? Centric morphology Pennate morphology23 24 6 Class Bacillariophyceae & Class Bacillariophyceae & Coscinodiscophyceae: Diatoms Coscinodiscophyceae: Diatoms • Most abundant group of marine phytoplankton Diatoms often form chains – look filamentous •Sometimes heterotrophic • Unicellular, sometimes colonial (chain forming) • Can be planktonic or benthic • Store oil as an energy reserve & help them float at the correct depth 25 26 Class Bacillariophyceae & Coscinodiscophyceae : Morphology Class Bacillariophyceae & Coscinodiscophyceae: Diatoms Movement Frustrules- Two-part boxlike cell walls •composed of silica (silicon dioxide, SiO2) •silicon can be a limiting nutrient for them •They secrete crystalline structures through Girdle - area of overlap of frustrules holes in the raphe or frustrules Raphe- central groove •These structures expand in H2O epitheca •This causes movement in opposite direction theca or frustrule •Movement regulated depending on which (each half) girdle holes they secrete through overlap hypotheca 27 28 7 Class Bacillariophyceae & Coscinodiscophyceae : Reproduction Class Bacillariophyceae & Coscinodiscophyceae :Life History •Division rates exceed one per day Diplontic: 2N thallus, the gametes are the only haploid stage •Asexual- individuals get smaller and smaller oogamous •Sexual- formation of auxospore, only way to get bigger 29 30 Division Heterokontophyta- 13,235 spp. Division Heterokontophyta- 13,235 spp. Class Coscinodiscophyceae -1717 spp. centric diatoms Class Coscinodiscophyceae -1717 spp. centric diatoms Genera: Coscinodiscus, Chaetoceros Genera: Coscinodiscus, Chaetoceros Common in coastal waters, epiphytic • Spines to slow sinking on seaweeds • Dense blooms can cause damage to fish gills Coscinodiscus Chaetoceros 31 32 8 Division Heterokontophyta- 13, 235 spp. Division Heterokontophyta- 13, 235 spp. Class Bacillariophyceae - 7249 spp. pennate diatoms Class Bacillariophyceae - 7249 spp. pennate diatoms Genera: Navicula, Pseudo-Nitzschia Genera: Navicula, Pseudo-Nitzschia • Unicells or in chains • Produces anti-herbivory • Common in rocky intertidal compound Domoic Acid • Accumulate in anchovies, eaten by birds death and strange behavior Navicula chain Pseudo-Nitzschia Navicula 33 34 Dinophyta, Haptophyta, Bacillariophyceae & Class Bacillariophyceae & Coscinodiscophyceae : Human Uses Coscinodiscophyceae Only phytoplankton with economic value Petroleum & Natural Gas: •Formed over millions of years from dead diatoms Diatomaceous earth: •Mined for filtration purposes , water filters (porous) •Pesticides (plugs up trachea) 35 39 Phytoplankton 36 9 Primary Production Primary Production • Phytoplankton are the major contributors to primary production in • Phytoplankton are at the base of marine food chains the open oceans………………………………………………………………..and globally! or webs primary producers •Primary Production: the amount of light energy converted to organic compounds by an ecosystems autotrophs during a given time period • Chlorophyll a is often measured as a proxy for primary production by phytoplankton •Important players phytoplankton produce over 99% of •Photosynthesis carried out primarily by: the food supply for marine animals •Phytoplankton – open ocean 37 38 •Macroalgae – along the coast Phytoplankton are the base of pelagic food webs Environmental Factors • Light •Nutrients •Stratification 39 40 5 10 Light Light • Major factor limiting new cell production • Limited to growth in the photic zone – near the surface • Photic zone •euphotic zone <200m (good light) •disphotic zone 200-1000m • Compensation depth = depth at which photosynthesis is equal to (small but measurable light) respiration (net production
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    Vol. 346: 75–88, 2007 MARINE ECOLOGY PROGRESS SERIES Published September 27 doi: 10.3354/meps07026 Mar Ecol Prog Ser OPENPEN ACCESSCCESS Tropical phytoplankton community development in mesocosms inoculated with different life stages Karolina Härnström1,*, Anna Godhe1, V. Saravanan2, Indrani Karunasagar2, Iddya Karunasagar2, Ann-Sofi Rehnstam-Holm3 1Department of Marine Ecology, Marine Botany, Göteborg University, PO Box 461, 405 30 Göteborg, Sweden 2Department of Fishery Microbiology, College of Fisheries, Karnataka Veterinary Animal and Fisheries Sciences University, PO Box 527, Mangalore 575 002, India 3Institution of Mathematics and Natural Sciences, Kristianstad University, 291 88 Kristianstad, Sweden ABSTRACT: Many diatom species have the ability to form benthic resting stages, but the importance of these stages as a supply for planktonic blooms is uncertain. A mesocosm study was carried out in December 2005 to January 2006 in Mangalore, India. Mesocosms were inoculated with various com- binations of benthic and/or planktonic cells, sampled from the coastal SE Arabian Sea, and the devel- opment of the planktonic community was followed. Diatoms dominated the phytoplankton commu- nity in all mesocosms, irrespective of inoculum. The most significant differences among inoculum types were altered species composition, and the timings of the maximum cell abundances, which lagged behind in the sediment mesocosms. Populations of Thalassiosira were initiated by both plank- ton and benthic propagules. Taxa known from temperate coastal areas to seed bloom by benthic propagules, such as Chaetoceros and Skeletonema, were predominantly seeded by planktonic cells in this experiment; this implies differential seeding strategy within the same species at different latitudes. The species assemblage encountered in the plankton and sediment was similar, which indicates that the benthic resting stages seed an autochthonous phytoplankton flora in the area.
  • Life in the Oceanic Realms

    Life in the Oceanic Realms

    GENERAL ¨ ARTICLE Life in the Oceanic Realms Chandralata Raghukumar The marine environment includes the nutrient-rich coastal waters, relatively nutrient-poor open oceanic waters, coral reef atolls, metal-rich hydrothermal vent fluids with tem- peratures of 200-350oC, cold-seeps, estuaries, mangrove swamps, intertidal beaches and rocky shores. Oceans are home to some of the most diverse and unique life forms. This Chandralata Raghukumar article is an attempt to introduce some of the fundamentals of is an emeritus scientist at biologicaloceanography andmarine biologyto describe life in the National Institute of the sea. Oceanography, Goa. After obtaining a PhD in plant I’dliketobeunderthesea, pathology, she worked for 5 years on fungal diseases In an octopus’s garden in the shade, of marine algae in the We would be warm below the storm, Institute for Marine In our little hideaway beneath the waves, Research, Bremerhaven, We would be so happy, you and me, Germany. At NIO she worked on algal and coral No one there to tell us what to do. pathology and marine fungal biotechnology. Her May this song by the Beatles be an inspiration to a career in major interests are biological oceanography! The general notion about oceanogra- industrially important phy research revolves around scuba diving, killer whales, sharks, enzymes from marine fungi and physiology of giant octopus and lobsters. But the oceans are much more than deep-sea fungi. these. Oceans are home to some of the most diverse life forms. These vary from whales, several metres long to bacteria smaller than a micron, creatures drab to stunning looking, sedate to constant swimmers, those which eat from anything to everything and those which are choosy about their meals.