1. Prokaryotes – Bacteria and Archea No membrane bound organelles Large surface area to volume ratio Asexual reproduction by binary fusion Single celled or colonial

2. Anaerobic metabolism – what’s going on in the hypolimnion of a stratified, anoxic lake? Chemoheterotrophs and Photohetertrophs – using active transport, more efficient at low nutrient concentrations Photoautotrophs – i.e. cyanobacteria (blue-green algae) Ecology Diapause – it may be that the dormancy is very important in bacteria

3. Cyanobacteria Prokaryotes (no nucleus or organelles) Blue-green Pigment = Chl a

4. Filamentous blue-green algae (Cyanophyta)

8. Protista – Protozoa and algae Eukaryotic (membrane bound organelles, nucleus, mitochondria, chloroplasts in photosynthetic protists) Single celled (although may be colonial)

9. Protozoa Also Giardia and Cryptosporidium Heterotrophic Protists Paramecium, amoebas, Euglena, Hydra

10. Photoautotrophic Protista – Algae Single celled or colonial Floating Phytoplankton Benthic algae Attached to surfaces (rocks, sediment)

11. Chlorophyta - Green Green-yellow green Pigment = Chl a and b Some have flagella

12. Chrysophyta Yellow green to golden brown Pigment = Chl a and c Some have 2 flagella

13. Chrysophyta (Golden-brown algae) Diatoms Brown to light green Pigment = Chl a and c Some have flagella Silica walls – composed of 2 frustules

14. Euglenophyta Pigment = Chl a and b All have flagella Eyespots Most are heterotrophic and autotrophic

15. Dinoflagellata Gray Pigment = Chl a and c Two flagella Some are highly toxic

16. Pfisteria

18. Reproduction - diverse Vegetative cell resistant cell (resting stage) Encystment Germination Asexual reproduction usually binary fission Sexual reproduction – possibly motile gametes or conjugation tubes

19. Fungi Yeasts Hyphae grouped into mycellium Chemoautotrophs (saprobic) Sexual and asexual reproduction

20. Ecological importance Breakdown of detritous Parasites on other aquatic organisms

21. Periphyton (or aufwuchs) – pond scum

22. A community of algae, fungi, bacteria