Dinophyta, Haptophyta, Bacillariophyceae &

Phytoplankton 1

DOMAIN Groups ()

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- with extracellular digestion

8. - unicellular

9. Animals- multicellular heterotrophs 2

1 Eukaryotes

Chromista = 17,500 spp. derived from 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

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Domain Eukaryotes – have a nucei Group Alveolates- 4,000 spp. Division Haptophyta- 576 spp. coccolithophore

sphere of stone 4

2 Division Haptophyta: Coccolithophore

• Pigments?

•Carbon Storage?

• Chloroplasts?

•Flagella?

•Life History? 5

Division Haptophyta: Coccolithophore

Autotrophic, Phagotrophic & Osmotrophic (uptake of nutrients by osmosis)

Primary producers in polar, subpolar, temperate & tropical waters

Coccoliths- external body scales made of calcium - keep out bacteria & - predatory defense - focus light into cells & nutrient uptake

Haptonema- thread like extension involved in prey capture - Phagotrophic lack and have haptonema 6

3 Haptophyta & Global Biochemistry

•Carbon & sulfer cyclingglobal climate

• floor limestone accumulation -largest long term sink of inorganic carbon

•25% of total carbon to deep ocean from coccoliths

•Produce large amounts of Dimethylsulfide (DMS) & reflect light - Increase acid rain - Enhance cloud formation – sulfate aerosols - Cooling influence on climate

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Division Haptophyta- coccolithophore Genera: Emiliania •Smallest unicellular •Ubiquitous throughout top 200m •Tremendous blooms •Armored coating makes the surface more reflective •Cools deeper ocean water •Contributes to global warming bc increases the amount of dissolved CO2 in the water

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4 Domain Eukaryotes – have a nuclei Group Alveolates- 4,000 spp. Division Dinophyta- 3051 spp. of dinoflagellates

whirling flagella

Pyrrhos = “fire” bioluminescent

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Division Dinophyta: Dinoflagellates

• Pigments?

•Carbon Storage?

• Chloroplasts?

•Flagella?

•Life History? 10

5 Xanthophyll Peridinin - a light harvesting carotenoid - unique in its high ratio of peridinin to chlorophyll 8:2 - makes red tides red

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Division Dinophyta

• Can be heterotrophic (eats food) or autotrophic (makes own food), 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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6 Dinophyta Life History Haplontic: 1N thallus, the is the only diploid stage

Normal conditions: Asexual

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

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Dinophyta Morphology

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

Tranverse undulipodium ()

Longitudinal undulipodium (flagellum)

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7 Dinophyta Movement

• Have a slight capacity to move into more favorable areas to increase productivity

• Use flagella to move

• Longitudinal flagellum  propels in the opposite direction

• Transverse flagellum  this flagella allows for turning and maneuvering

• Some dinoflagellates (<5%) have eyespots that allow detection of light source (mostly fresh water)

• Trichocysts???

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Dinophyta Morphology -Genus determined by number & arrangement of thecal plates

Apical Pore Thecal Plates (Cellulose) Epicone

Girdle or Cingulum Transverse Undulipodium Hypocone

Trichocyst Pores Sulcul Groove Longitudinal Undulipodium

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8 Spines • Larger SA/V • Helps to stay suspended in water column

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Dinophyta Genera: Gymnodinium, Noctiluca, • 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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9 Dinophyta Genera: Gymnodinium, Noctiluca, Symbiodinium

• Obligate • Bioluminescent! • Large – up to 2mm

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Bioluminescense

• Ancient mariners thought “the burning ” were of supernatural origin

• The next hypotheses were that the light was emitted from salt molecules or burning phosphorous

• 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 compounds) which is oxidized and results in the emission of light20

10 Dinophyta Genera: Gymnodinium, Noctiluca, Symbiodinium • zooxanthella • endosymbiont of corals, anemones, foraminiferans and radiolarians • provides host with up to 90% of energy requirements

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Domain Eukaryotes – have a nuclei Group Stramenopiles- 13,500 spp Division Heterokontophyta- 13, 235 spp. Class Bacillariophyceae- 7249 spp. pennate diatoms Class Coscinodiscophyceae -1717 spp. centric diatoms

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11 Class Coscinodiscophyceae

Class Bacillariophyceae

Centric morphology Pennate morphology23

Class Bacillariophyceae & Coscinodiscophyceae: Diatoms

• Pigments?

•Carbon storage?

• Chloroplasts?

• Flagella?

• Life History?

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12 Class Bacillariophyceae & Coscinodiscophyceae: Diatoms

• Most abundant group of marine

•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: Diatoms

Diatoms often form chains – look filamentous

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13 Class Bacillariophyceae & Coscinodiscophyceae: Morphology

Frustrules- Two-part boxlike cell walls •composed of silica (silicon dioxide, SiO2) •silicon can be a limiting nutrient for them

Girdle - area of overlap of frustrules

Raphe- central groove

epitheca

theca or frustrule girdle (each half)

overlap

hypotheca 27

Class Bacillariophyceae & Coscinodiscophyceae: Diatoms Movement

•They secrete crystalline structures through holes in the raphe or frustrules

•These structures expand in H2O

•This causes movement in opposite direction

•Movement regulated depending on which holes they secrete through

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14 Class Bacillariophyceae & Coscinodiscophyceae: Reproduction •Division rates exceed one per day •Asexual- individuals get smaller and smaller

•Sexual- formation of , only way to get bigger 29

Class Bacillariophyceae & Coscinodiscophyceae:Life History Diplontic: 2N thallus, the gametes are the only haploid stage oogamous

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15 Division Heterokontophyta- 13,235 spp. Class Coscinodiscophyceae -1717 spp. centric diatoms

Genera: Coscinodiscus,

Common in coastal waters, epiphytic on

Coscinodiscus

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Division Heterokontophyta- 13,235 spp. Class Coscinodiscophyceae -1717 spp. centric diatoms

Genera: Coscinodiscus, Chaetoceros

• Spines to slow sinking • Dense blooms can cause damage to fish gills

Chaetoceros

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

Genera: , Pseudo-Nitzschia

• Unicells or in chains • Common in rocky intertidal

Navicula chain

Navicula 33

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

Genera: Navicula, Pseudo-Nitzschia • Produces anti-herbivory compound Domoic Acid • Accumulate in anchovies, eaten by birds  death and strange behavior Pseudo-Nitzschia

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17 Class Bacillariophyceae & Coscinodiscophyceae: Human Uses

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)

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Dinophyta, Haptophyta, Bacillariophyceae & Coscinodiscophyceae

Phytoplankton 36

18 Primary Production

• Phytoplankton are at the base of marine food chains 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 for primary production by phytoplankton

•Important players phytoplankton produce over 99% of the food supply for marine animals 37

Primary Production • Phytoplankton are the major contributors to primary production in the open ………………………………………………………………..and globally!

• carried out primarily by: •Phytoplankton – open ocean 38 •Macroalgae – along the coast

19 Phytoplankton are the base of pelagic food webs

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Environmental Factors

• Light

•Nutrients

•Stratification

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20 Light

• Major factor limiting new cell production

• Limited to growth in the – near the surface

• Photic zone •euphotic zone <200m (good light) •disphotic zone 200-1000m (small but measurable light)

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Light

• Compensation depth = depth at which photosynthesis is equal to respiration (net production = 0)

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

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

21 Nutrients •Major factor limiting new cell production (especially N, Fe, Si for diatoms)

•Nutrient Sources: • Rivers, streams, and agriculture (runoff) • • Defecation • Decomposition • fixers

•Nutrient uptake: • Advantage of small size • Simple diffusion to supply nutrients and remove wastes - large SA/V ratio

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Stratification influences: • time spent in the photic zone • nutrient availability (e.g. nutrients sink)

•The photic zone is often shallower than the upper mixed layer but cells circulating in the mixed layer are continually brought into the photic zone •Nutrients are generally low in surface waters and higher at depth •Pycnocline limits vertical mixing to the upper regions of lakes and oceans, once cells sink below it they are lost from the pop.

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22 Importance of Iron

• In nitrogen rich waters – what is limiting???

+ • NH4 (Amonium) is utilized directly

- •NO3 (Nitrate) assimilation by nitrate reductase requires iron

- • Algae need iron to utilize Nitrate (NO3 ) as a nitrogen source

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“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 • Phyto bloom would take CO production in nutrient rich 2 out of the atmosphere seas • CO2 is a greenhouse gas causing global warming

•Iron addition experiment in the Pacific (500 km south of the Galapagos Islands– Mid October 1993 ) – added Fe to 64 sq km

•John died of cancer before he could see the outcome

• Phytoplankton ↑ 85X

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

23 Satellite picture of a phytoplankton bloom in the Southern Ocean induced by 47

Eutrophication

Too much of a good thing (primarily in lakes and nearshore coastal habitats): • Excess nutrients can cause , often from runoff • Over enrichment of N + P • Excessive growth of algae out-competes other organisms, decay of biomass results in anoxia • A big problem in the Baltic 48

24 Ecology

Population Growth of Phytoplankton

Pop growth = rate of new cell production – rate of cell loss (sedimentation/sinking + grazing)

•Floating and sinking •Grazing

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Floating and Sinking

• Most phytoplankton are denser than water + tend to sink

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

• Viscous drag slows sinking rates

• Shape: Elongate cells have more SA/V ratio than spherical cells – slow sinking in elongate

• Colonial chain forming arrangements slow sinking

• Water mixing suspends cells

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25 to slow sinking or aid in resuspension

•Spines to prevent sinking •Some species replace carbohydrates with lipids as a storage product (oils = more buoyant) •Swimming with flagella (phototaxis) •Ionic exchange: • Move ions in and out of cell to increase or decrease density

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Grazers

•Suspension feeding (filter water)

• Direct feeding

• May remove size specific individuals

• 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 effect) 52

26 Grazers Phytoplankton defenses:

o Increase rates of production

o Mucilage sheaths

o Thick walls

o Hard external coverings

o Spines are more for buoyancy but could also protect

o Form colonies (become too large for some to handle

o Chemical deterrents (toxic species) – e.g. Paralytic Shellfish Poisoning 53

Phytoplankton as indicators of changing environments

• Phytoplankton depend upon sunlight, water, and nutrients

• Variance in any of these factors over time will affect phytoplankton concentrations

• Phytoplankton respond very rapidly to environmental changes

• Changes in the trends for a given phytoplankton population (i.e. density, distribution, or pop growth rates) will alert scientists that environmental conditions are changing

•Oil companies monitor Haptophyta populations 54

27 increase nutrients in water (nitrogen & phosphorous) occur Spring to Fall (April – September in northern hemisphere) 2 million dinoflagellates/liter

1.blooms are not associated with tides 2.not all algal blooms cause reddish discoloration of water 3.not all algal blooms are harmful, even those involving red discolouration

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Harmful Algal Blooms: 1. the production of neurotoxins which cause mass mortalities in fish, seabirds and marine mammals 2. human illness or death via consumption of seafood contaminated by toxic algae 3. mechanical damage to other organisms, such as disruption of epithelial gill tissues in fish, resulting in asphyxiation 4.oxygen depletion of the water column (hypoxia or anoxia) from cellular respiration and bacterial degradation

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28 Seafoam: a complicated biochemical amalgam crushed phytoplankton- 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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