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Home , Auxospore, Chaetoceros, Coscinodiscophyceae

DOMAIN Groups () Dinophyta, Haptophyta, Bacillariophyceae & 1.Bacteria- (blue green ) 2.Archae 3. 1. Alveolates- ,

Chromista 2. Stramenopiles- , heterokonyophyta

3. Rhizaria- unicellular amoeboids

4. Excavates- unicellular

5. Plantae- rhodophyta, chlorophyta, seagrasses

6. Amoebozoans- slimemolds

7. Fungi- heterotrophs with extracellular digestion

8. - unicellular

9. Animals- multicellular heterotrophs 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 &

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 cyclingglobal climate •Smallest unicellular •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

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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

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3 Dinophyta Life History Dinophyta Morphology Haplontic: 1N thallus, the is the only diploid stage

• Posses two unequal flagella (at right angles to each other) • wall made up of cellulose plates (a carbohydrate) • Both flagella are hairy (not mastigonemes)

Normal conditions: Asexual Tranverse undulipodium () Stressful conditions: Fuse with another dinophyta to form hypnozygote (resilient resting stage)

Longitudinal undulipodium (flagellum)

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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

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4 Spines Dinophyta Genera: Gymnodinium, Noctiluca, • Larger SA/V • Helps to stay suspended in water column • Causes red tides when in high concentrations • Produces , a type of neurotoxin. • Poisons humans who eat shellfish that have been filtering it.

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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

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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

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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 are the only haploid stage •Asexual- individuals get smaller and smaller oogamous

•Sexual- formation of , 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, Genera: Coscinodiscus, Chaetoceros

Common in coastal waters, epiphytic • Spines to slow sinking on • Dense blooms can cause damage to fish gills

Coscinodiscus Chaetoceros

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8 Division Heterokontophyta- 13, 235 spp. Division Heterokontophyta- 13, 235 spp. Class Bacillariophyceae - 7249 spp. pennate diatoms Class Bacillariophyceae - 7249 spp. pennate diatoms

Genera: , 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 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

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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 = 0)

• Below this depth = phytoplankton die (can’t grow and deplete reserves)

41 6 • Above this depth = phytoplankton grow and are happy 42 7

Stratification influences: • time spent in the photic zone Nutrients • nutrient availability (e.g. nutrients sink) •Major factor limiting new cell production (especially N, Fe, Si for diatoms) •The photic zone is often

shallower than the upper mixed •Nutrient Sources: layer but cells circulating in the • Rivers, streams, and agriculture (runoff) • Upwelling mixed layer are continually • Defecation brought into the photic zone • Decomposition •Nutrients are generally low in • Nitrogen fixers surface waters and higher at depth •Nutrient uptake: •Pycnocline limits vertical mixing • Advantage of small size to the upper regions of lakes and • Simple diffusion to supply nutrients and remove wastes oceans, once cells sink below it - large SA/V ratio they are lost from the pop.

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11 Importance of Iron “With half a shipload of Fe, Importance of Iron I could give you an ice age” John Martin’s Hypothesis • 1988 (MLML) Reasoning: • Iron limits phytoplankton • In nitrogen rich waters – what is limiting??? production in nutrient rich • Phyto bloom would take CO2 out of the atmosphere seas + • CO2 is a greenhouse gas • NH4 (Amonium) is utilized directly causing global warming

- •NO3 (Nitrate) assimilation by nitrate reductase •Iron addition experiment in the Pacific (500 km south of the requires iron Galapagos Islands– Mid October 1993 ) – added Fe to 64 sq km

- •John died of cancer before he could see the outcome • Algae need iron to utilize Nitrate (NO3 ) as a nitrogen source • Phytoplankton ↑ 85X

• Expt. repeated in the Southern Ocean with similar results 45 46

Eutrophication

Too much of a good thing (primarily in lakes and nearshore coastal habitats): • Excess nutrients can cause eutrophication, often from runoff • Over enrichment of N + P Satellite picture of a phytoplankton bloom in the Southern • Excessive growth of algae out-competes other organisms, decay Ocean induced by iron fertilization of biomass results in anoxia 47 • A big problem in the Baltic Sea 48

12 Ecology Floating and Sinking • Most phytoplankton are denser than water + tend to sink

• Stay suspended by water movements and viscous (resistance of fluid Population Growth of Phytoplankton to something moving through it) drag (mechanical force of a solid moving through a fluid)

Pop growth = rate of new cell production – rate of • Viscous drag slows sinking rates cell loss (sedimentation/sinking + grazing) • Shape: Elongate cells have more SA/V ratio than spherical cells – slow sinking in elongate

• Colonial chain forming arrangements slow sinking •Floating and sinking •Grazing • Water mixing suspends cells

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Adaptations to slow sinking or aid in resuspension Grazers

•Spines to prevent sinking •Suspension feeding (filter water) •Some species replace carbohydrates with lipids as a storage product (oils = more buoyant) • Direct feeding •Swimming with flagella (phototaxis) •Ionic exchange: • May remove size specific individuals • Move ions in and out of cell to increase or decrease density • May remove less resistant Phytoplankton species – non-toxic spp

• Results in patchy distributions

Grazers may also increase Phytoplankton populations by releasing nutrients through excretion (positive 51 effect) 52

13 Phytoplankton as indicators of Grazers changing environments Phytoplankton defenses: • Phytoplankton depend upon sunlight, water, and nutrients o Increase rates of production • Variance in any of these factors over time will affect o Mucilage sheaths phytoplankton concentrations

o Thick walls • Phytoplankton respond very rapidly to environmental o Hard external coverings changes

o Spines are more for buoyancy but could also protect • Changes in the trends for a given phytoplankton

o Form colonies (become too large for some to population (i.e. density, distribution, or pop growth rates) handle will alert scientists that environmental conditions are changing o Chemical deterrents (toxic species) – e.g. Paralytic Shellfish Poisoning •Oil companies monitor Haptophyta populations 53 54

Red tide Harmful Algal Blooms: increase nutrients in water (nitrogen & phosphorous) 1. the production of neurotoxins which cause mass occur Spring to Fall mortalities in fish, seabirds and marine mammals (April – September in northern hemisphere) 2. human illness or death via consumption of seafood 2 million dinoflagellates/liter contaminated by toxic algae 3. mechanical damage to other organisms, 1.blooms are not associated with tides such as disruption of epithelial gill tissues in fish, 2.not all algal blooms cause reddish discoloration of water resulting in asphyxiation 3.not all algal blooms are harmful, even those involving red 4.oxygen depletion of the water column (hypoxia or discolouration anoxia) from cellular respiration and bacterial degradation

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14 Seafoam: a complicated biochemical amalgam crushed phytoplankt on- consist of inorganic and organic particles of proteins, carbohydrates, and lipids proteins provide surface tension to allow the bubbles to form bubbles arise from agitation of the surf

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