Cyanophyta and flagellates
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Cyanophyta and Flagellates. Lecture 10. OVERVIEW. Eubacteria & Protists Cyanophyta “ Phytoplankton ” Chlorophyta, Phaeophyta, Rhodophyta Vascular Plants (Gymnosperms & Angiosperms) Seagrasses – Hydrocharitaceae & Potamogetonaceae Saltmarshes – Poaceae, Juncaceae, etc

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Cyanophyta and Flagellates

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Cyanophyta and Flagellates

Lecture 10


OVERVIEW

Eubacteria & Protists

  • Cyanophyta

  • “Phytoplankton”

  • Chlorophyta, Phaeophyta, Rhodophyta

    Vascular Plants (Gymnosperms & Angiosperms)

  • Seagrasses – Hydrocharitaceae & Potamogetonaceae

  • Saltmarshes – Poaceae, Juncaceae, etc

  • Mangroves – Rhizophoraceae, Avicenniaceae

  • Beach & Dune plants


Fan-Shaped Phylogenetic Tree


Falkowski & Raven 2007


Algal pigments


“Endosymbiosis” Theory

  • Eukaryotic cells captured and ingested prokaryotic cells and “tamed” them to become organelles (Chloroplasts, Mitochondria – have own DNA).

  • Chloroplasts from blue-green algal cells,

  • Mitochondria from bacteria

  • Flagellum (9+2 microtubules) from motile, saprophytic prokaryote

  • Rhodophyta ingested a Cyanobacteria (chloroplast with phycobiliproteins)


Organelles and endosymbiosis

During the 1980s, Lynn Margulis proposed the theory of endosymbiosis to explain the origin of mitochondria and chloroplasts from permanent resident prokaryotes. According to this idea, a larger prokaryote (or perhaps early eukaryote) engulfed or surrounded a smaller prokaryote some 1.5 billion to 700 million years ago.

The basic events in endosymbiosis. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.


Falkowski & Raven 2007


“Cyanophyta”

  • = cyanobacteria or blue-green algae

  • Prokaryote Eubacteria– organelles lacking

  • Unicellular, colonial, filamentous forms

  • Chl a + Phycocyanin (blue), Phycoerythrin (red), Zeaxanthin

  • Heterocysts & N-fixation

  • http://www-cyanosite.bio.purdue.edu


Heterocysts – N fixation

Triple layer cell wall:

glycolipid and polysaccharide

  • Differentiated cell that provides a low O2 environ for N-fixation (nitrogenase)

  • Oxygen diffusion 100x lower than normal cell

  • No photosystem II – no p’synth

  • Higher respiration (uses up O2)

  • Under genetic control – up regulated under low N, 1 in 10 cells become heterocysts, within 24 hrs, 600-1000 genes involved.

NH4

N2

http://biology.kenyon.edu/Microbial_Biorealm/bacteria/anabaena/anabaena.htm

http://www2.hawaii.edu/~scallaha/SMCsite/Research.html


Heterocysts – N fixation

Triple layer cell wall:

glycolipid and polysaccharide

  • Differentiated cell that provides a low O2 environ for N-fixation (nitrogenase)

  • Oxygen diffusion 100x lower than normal cell

  • No photosystem II – no p’synth

  • Higher respiration (uses up O2)

  • Under genetic control – up regulated under low N, 1 in 10 cells become heterocysts, within 24 hrs, 600-1000 genes involved.

NH4

N2


Cyanophyta

  • Stromatolites –Bermuda, Shark Bay

  • 3.5 Bio – 600 Mio

  • O2 production – red bands (FeOx)

  • Warm, low energy, low grazing.

  • http://stromatolites.info/


Cyanophyta

  • Stromatolites –Bermuda, Shark Bay

  • 3.5 Bio – 600 Mio

  • O2 production – red bands (FeOx)

  • Warm, low energy, low grazing.

  • http://stromatolites.info/


Cyanophyta

  • Stromatolites –Bermuda, Shark Bay

  • Lyngbya

  • Oscillatoria

  • Scytonema


Cyanophyta

  • Stromatolites –Bermuda, Shark Bay

  • Lyngbya

  • Oscillatoria

  • Nostoc

  • Trichodesmium


Div Cyanophyta taxonomy

  • Single class: Cyanophyceae.

  • No flagellae, no organelles

  • No sexual reproduction, use transformation and conjugation (bacterial recombinant process)

  • Mostly freshwater, some marine and terrestrial habitats (including glaciers, hot springs, etc.)

  • 150 genera, 2000 spp

  • Prefer warm, quiescent water, often higher salinities.

  • Important members of the picoplankton (0.2-2um)

  • 5 Orders: Chroococcales, Pleurocapsales, Oscillatoriales, Nostocales, Stigonematales


“Thallus” organization

  • Unicells – Chroococales

  • Colonial – Pleurocapsales

  • Filamentous – Oscillatoriales, Nostocales

  • Simple parenchymatous – Stigonematales

  • Two taxonomic systems:

  • Geitler (1932) based on morphology

  • Stanier (1977) based on axenic clonal culture (bacteriological techniques)

http://tolweb.org/Cyanobacteria/2290

http://www-cyanosite.bio.purdue.edu/images/images.html


Or. Chroococales

Chroococcus

Microcystis


Or. Pleurocapsales

CyanocystisPleurocapsa

Black bands on seashore rocks


Or. Oscillatoriales - Stromatolites

Lyngbya

Trichodesmium

Lyngbya

Oscillatoria

Microcoleus


Or. Nostocales

Heterocysts

Nostoc

Anabaena

Autofluorescence image


Or. Stigonematales

Fisherella


Microbial Mats

http://www.marine.unc.edu/Paerllab/sansalmo/index.htm


Cyanophyta summary

  • Prokayotic Eubacteria

  • Simplest photosynthesizers – stromatolites and atmospheric oxygen

  • N-fixation in heterocysts

  • Oscillatoriales most important marine order.

  • Can form blooms: toxins, anoxia

  • Microbial Mats important area of research


“Phytoplankton”

  • Passive floating

  • Photic Zone (0-100m depth = 0.1% PAR)

  • Diurnal Vertical Migration (DVM)

  • Sampling – Plankton Net (mesh = 40-76mm mesh size, silk or nylon).

  • 30 yr N. Atl dataset - Continuous Plankton Records (CPR): Plankton Atlas of the North Atlantic Ocean (1958–1999). MEPS Suppl. 3, 2004.


“Phytoplankton”

  • Size: net- (40-80+mm), nanno- (2-20mm), pico- (0.2-2mm), ultra- (<0.2mm)

  • Filtering, microscopy cell counts.

  • 47 Pigments: chls + accessory pigments

  • Analysis by HPLC (High Performance Liquid Chromatography)

  • Pigments have potential use in Remote Sensing of presence/concentration


“Phytoplankton”

  • Unicells

  • Filamentous

  • Colonies – chains, or spheres


Flagellates

  • Mixed bag taxonomically, includes “picoplankton (<2mm)”

  • “naked” – don’t preserve well, need to be studied while living

  • Size <1mm – 1mm

  • >1x109 cells / Liter in blooms!

  • Ubiquitous, poorly studied to date


Flagellates

Euglena


2 central + 9 axial microtubules

Single or paired

Anterior, posterior flagellum

Smooth or “hairy”

Basal body = anchoring structure

Flagellum


2 central + 9 axial microtubules

Single or paired

Anterior, posterior flagellum

Smooth or “hairy”

Basal body = anchoring structure

Flagellum


Division Chromophyta

Cryptophyceae

Division Heterokontophyta

Dinophyceae (naked Dinoflagellates)

Raphidophyceae

Chrysophyceae

Xanthophyceae

Dictyochophyceae

Prymnesiophyceae

Chl a + accessory pigments (carotenoids)

Division Chlorophyta

Class:

Euglenophyceae

Prasinophyceae

Chlorophyceae - Chlamydomonas

Chl a + b

Flagellates


Class Euglenophyceae

  • Can also be placed in Div. Euglenophyta

  • Chl a+b

  • Eyespot

  • Mainly FW, some marine

  • 6 orders, 40 genera, 800 spp

  • Heterotrophy important


Class Euglenophyceae

  • Single Class – Euglenophyceae

  • Chl a+b

  • Eyespot

  • Mainly FW, some marine

  • 6 orders, 40 genera, 800 spp

  • Heterotrophy important


Class Prasinophyceae

  • 4 Orders, 16 genera, 180 spp

  • Cells with 1-8 flagellae

  • Bathycoccus - picoplankton (0.5-2um), N. Atlantic

  • Pterosperma - large (100-800um) cyst-like stages = phycomata. Fossil cysts from 1.2 Bya.


Class Prasinophyceae

  • 4 Orders, 16 genera, 180 spp

  • Cells with 1-8 flagellae

  • Bathycoccus - picoplankton (0.5-2nm), N. Atlantic

  • Pterosperma - large (100-800nm) cyst-like stages = phycomata. Fossil cysts from 1.2 Bya.


Class Chlorophyceae

  • 4 orders, 355 genera, 2650 spp – only v few marine.

  • Or Volvocales – unicell & colonial, Chlamydomonas, Volvox

  • Or Chlorococcales – unicell -> siphononous,Chlorella (1-2um), endosymbiont in tropical foramifera, Scenedesmus (brackish, eutrophic)

  • Or Chaetophorales – no marine spp

  • Or Oedogoniales – filamentous,Oedogonium 400spp


Class Chlorophyceae

  • 4 orders, 355 genera, 2650 spp – only v few marine.

  • Or Volvocales – unicell & colonial, Chlamydomonas, Volvox

  • Or Chlorococcales – unicell -> siphononous,Chlorella (1-2um), endosymbiont in tropical foramifera, Scenedesmus (brackish, eutrophic)

  • Or Chaetophorales – no marine spp

  • Or Oedogoniales – filamentous,Oedogonium 400spp


Division Chromophyta

Cryptophyceae

Division Heterokontophyta

Dinophyceae (naked Dinoflagellates)

Raphidophyceae

Chrysophyceae

Xanthophyceae

Dictyochophyceae

Prymnesiophyceae

Chl a + accessory pigments (carotenoids)

Division Chlorophyta

Class:

Euglenophyceae

Prasinophyceae

Chlorophyceae - Chlamydomonas

Chl a + b

Flagellates


Class Cryptophyceae

  • 12 genera, 200 spp, ½ marine

  • Biflagellate, ventral gullet with trichocysts, accessory pigments (phycobilins, xanthophylls, carotenes)

  • Dominate nannoplankton (2-20um) in North Sea spring blooms – Cryptomonas

  • Massive blooms of Mesodinium in upwelling zones (Peru, Baja California)


Class Cryptophyceae

  • Class Cryptophyceae – 12 genera, 200 spp, ½ marine

  • Biflagellate, ventral gullet with trichocysts, accessory pigments (phycobilins, xanthophylls, carotenes)

  • Dominate nannoplankton (2-20um) in North Sea spring blooms – Cryptomonas

  • Massive blooms of Mesodinium in upwelling zones (Peru, Baja California)

Cryptomonas


Class Raphidophyceae

  • Heterokont = long tinsel flagellum anterior, short smooth flag posterior

  • 1. Class Raphidophyceae – 9 genera.

  • Unicell flagellates, 2 flagellae, cells 50-100um, curved dorsal side, flattened ventral side with flagellar groove.

  • FW and marine – form HABs in Japan, DE

  • Chattonella, Fibrocapsa


Div Heterokontophyta

  • Heterokont = long tinsel flagellum anterior, short smooth flag posterior

  • Class Raphidophyceae – 9 genera.

  • Unicell flagellates, 2 flagellae, cells 50-100um, curved dorsal side, flattened ventral side with flagellar groove.

  • FW and marine – form HABs in Japan, DE

  • Chattonella, Fibrocapsa

Chattonella

Fibrocapsa


Class Chrysophyceae

  • Unicell, amoeboid, coccoid, filamentous forms

  • 2. Class Chrysophyceae, 3 orders, 200 genera, 1000 spp, v. few marine. Includes Pelagoccocus (picoplankt) and Sarcinochrysis (estuarine)

  • 3. Class Xanthophyceae, 7 orders, 100 genera, 600 spp, few marine. Includes the mat forming Vaucheria (50 spp) – siphonous construction


10 um

Class Xanthophyceae

  • Unicell, amoeboid, coccoid, filamentous forms

  • Class Chrysophyceae, 3 orders, 200 genera, 1000 spp, v. few marine. Includes Pelagoccocus (picoplankt) and Sarcinochrysis (estuarine)

  • Class Xanthophyceae, 7 orders, 100 genera, 600 spp, few marine. Includes the mat forming Vaucheria (50 spp) – siphonous construction

Vaucheria (from GCRL)

Pelagococcus


Class Dictychophyceae

  • 4. Class Dictyochophyceae – 2 spp extant

  • Single flagellum with mastigonemes (hairs). Siliceous skeleton (fossilizes well), 120 Mya evolved (silicoflagellates)

  • More prevalent cooler waters. Used to estimate historic SST.

  • Dictyocha fibula and D. speculum


Div Heterokontophyta

  • Class Dictyochophyceae – 2 spp extant

  • Single flagellum with mastigonemes (hairs). Siliceous skeleton (fossilizes well), 120 Mya evolved (silicoflagellates)

  • More prevalent cooler waters. Used to estimate historic SST.

  • Dictyocha fibula and D. speculum

Dictyocha


Summary

  • Flagellates part of phytoplankton – often picoplankton, poorly studied, don’t preserve well, very small, hard to ID

  • 2 groups – green pigments (Div Chlorophyta), brown pigments (Div Chromophyta / Heterokontophyta)

  • Some groups prone to blooms and HABs


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