I.I. ArchaeaArchaea

• Resemble bacteria superficially but Resemble bacteria superficially but may be more closely related to may be more closely related to eukaryotes than bacteriaeukaryotes than bacteria

• May be heterotrophs or autotrophsMay be heterotrophs or autotrophs• MethanogensMethanogens• Nitrogen fixersNitrogen fixers

• Important decomposersImportant decomposers• Abundant in sedimentsAbundant in sediments

• ExtremophilesExtremophiles• Sulfur rich hot springsSulfur rich hot springs• Acid/Alkaline lakes (Acid/Alkaline lakes (acidophilesacidophiles))• Hydrothermal vents (Hydrothermal vents (thermophilesthermophiles))• Deep sea (Deep sea (barophilesbarophiles))• Antarctic (Antarctic (psychrophilespsychrophiles))

II.II. Unicellular AlgaeUnicellular Algae

A.A. EukaryotesEukaryotes• Photosynthesis in chloroplastsPhotosynthesis in chloroplasts• Lack flowers, stems, leaves, rootsLack flowers, stems, leaves, roots

B.B. Diatoms (Bacillariophyta)Diatoms (Bacillariophyta)• UnicellularUnicellular

• May form chainsMay form chains• Cell enclosed by silica (SiOCell enclosed by silica (SiO22) ) frustulesfrustules ( (testtest))

• Test usually perforated and ornamented Test usually perforated and ornamented with spines or ribs (with spines or ribs (Why?Why?))

• Perforations allow gases, nutrients, waste Perforations allow gases, nutrients, waste products to pass through test to cellproducts to pass through test to cell

• Important open-water primary producers, Important open-water primary producers, especially in temperate and polar regionsespecially in temperate and polar regions

Fig. 15.3a

Fig. 4.8b

Fig. 5.5

II.II. Unicellular AlgaeUnicellular Algae

B.B. Diatoms (Bacillariophyta)Diatoms (Bacillariophyta)• ReproductionReproduction

• Asexual - Cell divisionAsexual - Cell division• Sexual - Egg + Sperm --> Sexual - Egg + Sperm --> AuxosporeAuxospore

Fig. 5.6

II.II. Unicellular AlgaeUnicellular Algae

B.B. Diatoms (Bacillariophyta)Diatoms (Bacillariophyta)• ReproductionReproduction• Explosive population growth --> Explosive population growth --> BloomBloom

• May deplete nutrients locallyMay deplete nutrients locally• Sediments beneath areas where diatoms are Sediments beneath areas where diatoms are

abundant may contain many testsabundant may contain many tests• Diatomaceous oozesDiatomaceous oozes• Diatomaceous earthDiatomaceous earth

II.II. Unicellular AlgaeUnicellular Algae

C.C. Dinoflagellates Dinoflagellates (Dinoflagellata/Pyrrophyta)(Dinoflagellata/Pyrrophyta)

• Possess two Possess two flagellaflagella• MotileMotile

• Covered with Covered with thecatheca made of cellulose plates made of cellulose plates• Theca may have spinesTheca may have spines

Fig. 5.7a

II.II. Unicellular AlgaeUnicellular Algae

C.C. Dinoflagellates Dinoflagellates (Dinoflagellata/Pyrrophyta)(Dinoflagellata/Pyrrophyta)

• Possess two Possess two flagellaflagella• MotileMotile

• Covered with Covered with thecatheca made of cellulose plates made of cellulose plates• Theca may have spinesTheca may have spines

• Important open-water primary producers, Important open-water primary producers, especially in tropical regionsespecially in tropical regions

• Trophically diverseTrophically diverse• AutotrophicAutotrophic• HeterotrophicHeterotrophic• MixotrophicMixotrophic

• May bloom like diatomsMay bloom like diatoms• Red tidesRed tides• Brown tidesBrown tides

http://www.whoi.edu/redtide/

II.II. Unicellular AlgaeUnicellular Algae

C.C. Dinoflagellates Dinoflagellates (Dinoflagellata/Pyrrophyta)(Dinoflagellata/Pyrrophyta)

• Some forms live symbiotically with corals, Some forms live symbiotically with corals, anemones, jellyfish, giant clams, spongesanemones, jellyfish, giant clams, sponges

• ZooxanthellaeZooxanthellae• Lose flagellaLose flagella• Especially important in reef building coralsEspecially important in reef building corals

• Some forms can be extremely toxicSome forms can be extremely toxic• PfiesteriaPfiesteria- Blooms triggered by coastal pollution- Blooms triggered by coastal pollution- Toxin can cause memory loss in humans- Toxin can cause memory loss in humans

II.II. Unicellular AlgaeUnicellular Algae

D.D. Other AlgaeOther Algae1.1. Silicoflagellates (Chrysophyta)Silicoflagellates (Chrysophyta)

• Silica test, usually with spinesSilica test, usually with spines• Single flagellumSingle flagellum

2.2. Coccolithophorids (Haptophyta)Coccolithophorids (Haptophyta)• Covered by calcium carbonate Covered by calcium carbonate coccolithscoccoliths• Coccoliths may be important components of Coccoliths may be important components of

sedimentssediments3.3. Cryptomonads (Cryptophyta)Cryptomonads (Cryptophyta)

• Lack skeletonLack skeleton• Two flagellaTwo flagella

Fig. 5.8

Fig. 5.9

III.III. ProtozoaProtozoa

A.A. ForaminiferansForaminiferans• Test (shell) made of calcium carbonate (CaCOTest (shell) made of calcium carbonate (CaCO33) or ) or

agglutinated sediment particlesagglutinated sediment particles• Fossil tests used to age geological depositsFossil tests used to age geological deposits

• May have multiple chambersMay have multiple chambers• Tests increase in size as organism growsTests increase in size as organism grows

• Feed by extending Feed by extending pseudopodiapseudopodia through pores in test through pores in test• Trap bacteria and other small organisms/detritusTrap bacteria and other small organisms/detritus

• Pelagic forms (calcareous)Pelagic forms (calcareous)• Often have spinesOften have spines• Tests may form Tests may form foraminiferan oozesforaminiferan oozes, esp. in , esp. in

shallow water beneath tropics (white cliffs of shallow water beneath tropics (white cliffs of Dover – England)Dover – England)

• Benthic forms (calcareous or agglutinated)Benthic forms (calcareous or agglutinated)• Calcareous tests can be important sources of sand Calcareous tests can be important sources of sand

for beachesfor beaches

http://earthguide.ucsd.edu/earthguide/imagelibrary/orbulinauniversa.html

http://www.ucl.ac.uk/GeolSci/micropal/foram.html

III.III. ProtozoaProtozoa

B.B. RadiolariansRadiolarians• Test made of silica (SiOTest made of silica (SiO22))• Tests may form Tests may form radiolarian oozesradiolarian oozes, esp. in deep water , esp. in deep water

in temperate and polar regionsin temperate and polar regions• Feed by extending pseudopodia through pores in testFeed by extending pseudopodia through pores in test

• Trap diatoms and other small organisms/detritus Trap diatoms and other small organisms/detritus ((Why diatoms?Why diatoms?))

C.C. Ciliates (Ciliophora)Ciliates (Ciliophora)• Use ciliaUse cilia

• LocomotionLocomotion• FeedingFeeding

• Free livingFree living• Pelagic (Tintinnids)Pelagic (Tintinnids) - - LoricaLorica• BenthicBenthic

• ParasiticParasitic

IV.IV. FungiFungi

• Unicellular or multicellularUnicellular or multicellular• Mostly microscopicMostly microscopic

• HeterotrophicHeterotrophic• Important decomposersImportant decomposers

• Especially in mangrove forestsEspecially in mangrove forests• Some disease causing formsSome disease causing forms

• Host to algae in lichensHost to algae in lichens

http://rmbr.nus.edu.sg/research/terrestrial/fungi.htm

V.V. Multicellular Algae - SeaweedsMulticellular Algae - Seaweeds

• MacroalgaeMacroalgae• Complex but lack specialized structures of true plantsComplex but lack specialized structures of true plants

A.A. General StructureGeneral Structure• Body = Body = thallusthallus• Flattened portion = Flattened portion = bladeblade

• Not true leavesNot true leaves• No veinsNo veins• Upper and lower surfaces identicalUpper and lower surfaces identical• No tissues for transport of water, nutrients & No tissues for transport of water, nutrients &

mineralsminerals• Increase surface area (Increase surface area (Why?Why?))• Main sites of photosynthesisMain sites of photosynthesis

• Float = Float = pneumatocystpneumatocyst• Anchor = Anchor = holdfastholdfast

• Do not penetrate sediment or absorb water & nutrientsDo not penetrate sediment or absorb water & nutrients

Fig. 6.1