1. Phycology: The Study of Algae

2. Some restricted to marine environment (reds and browns), some to freshwater (our focus) Characterized by morphology, biochemistry, pigments, reproductive methods, food reserves

3. Photosynthetic Pigments Chlorophylls –Chlorophyll a-found in all algae and macrophytes; the primary pigment Absorbance spectrum 660-665 nm and 430 nm –Chlorophyll b-only in chlorophyta, euglenophyta and charophyta; Absorbs about 435 nm and 645 nm –Chlorophyll c- accessory pigment Absorbs 630-635, 583-586, and 444-452 nm.

4. Accessory Pigments Carotenes-  and  are most common Xanthophylls-derivatives of carotenes –E.g., lutein, diatoxanthin, myxoxanthin, peridinin Biliproteins-almost exclusively in cyanophyta –E.g., phycocyanin, phycoerethryin

5. Cyanophyta (Blue-green algae) are prokaryotic bacteria; date to 3.5 BYA ~55% are blue-green ~15% are never blue-green; others may be green, olive, red, purple, black, or colorless Store food as glycogen (iodine negative) Never flagellate, but some can move (oscillate or glide) Reproduction –Sexual-not known –Vegetative-binary fission; fragmentation –Asexual Akinete-germinates directly Heterocyst-may divide either directly to a trichome or to endospores which ‘germinate’ to a trichome Presence of pseudovacuoles; gas-filled; affect buoyancy; may shade other species

6. Cyanophytes (continued) Nutrition: –Mostly autotrophic, some saprophytic –40 different kinds are N-fixers; all of these have heterocysts; do well in N-poor environments Aphanizomenon Anabaena Nostoc

7. Distribution-highly successful; terrestrial, aquatic, marine, epiphytic, on walls, soils, parasitic, planktonic; some can live at 80 o C. Economic importance –Rice paddy nitrogen fixation –Nostoc balls –Odors and flavors-musty, moldy –Allergies Coloration of flamingoes and shrimp

8. Merismopedia Nostoc balls SpirulinaOscillatoria

9. Lyngbia Microcystis Rivularia Scytonema false branching