1. C.5 Freshwater phytoplankton: diversity & biology
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5.1 Identifying freshwater phytoplankton
'algae' a large & very diverse: ~15 groups (divisions)
freshwater vs. marine
cf. benthic: stonewarts (Charophyta), red algae (Rhodophyta)
size, 1 ~500 ㎛; nano ~microplankton ranges
* DNA-based molecular species
@morphological features w/ microscope
- size, shape & colour of cells
- arrangement of cells (single, filamentous, colonial)
- type of cell wall
- P/A & position of flagella, organelles, specialised cells
Bold & Wynne 1986
South & Whittick 1987
Van den Hoek et al. 1995
Lee 1999
Sandgren 1988a
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5.2 Cyanobacteria (blue-green algae)
BOX 5.1 Cyanobacteria & other photosynthetic bacteria
BOX 5.2 Buuoyancy regulation in cyanobacteria ~ bacteria
Prokaryotes > Kingdom Eubacteria ~ higher plants
cf. all other algae belong to eukaryotes
! N2 fixation: leguminous plants
BOX 5.3 Heterocytes & Akinetes
Gram-negative bacteria, w/ lipopolysaccharides (potent toxins)
freshwaters; &terrestrial
3 orders of Australia: [Tab 5.1]
- Chroococcales: Microcystis aeruginosa (hepatotoxin), M. flosaquae, picoplanktonic Chroococcus Merismopedia Aphanocapsa Aphanothece Coelosphaerium
- Nostocales: most problem, Anabaena circinalis (neurotoxin, bloom), A. spiroides, Cylidrospermopsis raciborskii (hepatotoxin); Cuspidothrix Aphanizomenon Anabaenopsis
- Oscillatoriales: no hepato- neuro-toxin spp.; a toxic benthic Phormidium sp. & Lynbya wollei ; Planktothrix Planktolynbya Pseudanabaena Geitlerinema Planktotrichoides
C.5 Freshwater Phytoplanktn

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5.3 Chlorophyceae (green algae)
most numerous & diverse
~11 orders (~19 ord.), non-toxic
majority of planktonic sp.;
Chlorophyceae(녹조강) prim. freshwater group ~90%
- attached & benthic, planktonic
ord. Volvocales: Chlamydomonas, Gonium, Pandorina, Eudorina, Volvox, Pediastrum훈장말, Scenedesmus뗏목말, Desmodesmus, Chlorella, Oocystis
Desmids장구말, w/ two mirror-image halves, conjugation for zygote : Closterium, Cosmarium, Micrasterias, Staurastrum
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5.4 Bacillariophyceae (diatoms)
widely dist. freshwater & marine
planktonic, benthic, epiphytic [BOX 5.5]
planktonic: single, colony, filamentous
cell w/ hypo- & epivalve
! valve view vs. girdle view
Centrales: centric, radial Cyclotella Coscinodiscus Aulacoseirra
Pennales: pennate, bilateral Synedra Urosolenia Navicula; Asterionella Fragilaria Tabellaria; Cocconeis Surirella Pinularia
BOX 5.6 Vegetative reproduction in diatoms
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5.5 Pyrrhophyceae (or Dino-; Dinoflagellates)
'dinos' than marine
[BOX 5.7]
usual. single-celled, some filamentous
epicone+hypocone, w/ theca, two flagella
- armoured dinos: Peridinium Ceratium
- naked: Gymnodinium
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5.6 Other algae flagellated, motile algae
euglenoids div.Euglenophyceae: [BOX 5.8]
- Euglena, Phacus; Trachelomonas
cryptomonads [BOX 5.9]
- Cryptomonas, Rhodomonas
golden-brown algae acidic [BOX 5.10]
- Mallomonas, Synura; Dinobryon
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5.7 Conclusions ~7
- common 3 orders of cyanobacteria - great algae: flagellated vs. non-flagella.
- centric vs. pennate of diatoms
- armoured vs. naked of dinoflagellates & euglenoids
C.5 Freshwater Phytoplanktn