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Phycology: The Study of Algae

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Presentation on theme: "Phycology: The Study of Algae"— Presentation transcript:

1 Phycology: The Study of Algae

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

3 Photosynthetic Pigments
Chlorophylls Chlorophyll -found in all algae and macrophytes; the primary pigment Absorbance spectrum nm and 430 nm Chlorophyll -only in chlorophyta, euglenophyta and charophyta; Absorbs about 435 nm and 645 nm Chlorophyll c- accessory pigment Absorbs , , and nm.


5 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

6 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

7 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

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

9 Merismopedia Nostoc balls Oscillatoria Spirulina


11 Microcystis Rivularia Lyngbia Scytonema false branching


13 Diatoms


15 Centrales: centric diatoms
Radial symmetry Striae composed of linear punctae May be single-celled like Cyclotella (above) or colonial: in filaments or like Tabellaria (above)

16 Pennales: pennate diatoms

17 Pennales Bilateral symmetry
Many groups possess a raphe-these are motile; some have a pseudoraphe Generalization: pennate diatoms are more common in eutrophic waters, centrics in oligotrophic waters;

18 Green Algae: Chlorophytes



21 Rhodophyta: Red Algae Eukaryotic
Pigments: chlorophyll a & b, phycoerythrin Food storage: iodine negative starch Cellulose cell walls No flagellated cells Many marine species often used as thickeners due to their highly mucilaginous nature: agar, carageenans

22 Irish Moss (Chondrus crispus)

23 Porphyra (Nori)

24 Dulse (Palmaria palmata)

25 Predominantly marine group
Few FW representatives, especially locally Not necessarily ‘red’ in appearance Complex life cycles

26 Batrachospermum

27 Characteristic of cool, clear streams
Bangia atropurpurea Characteristic of cool, clear streams

28 Dinoflagellates

29 Dinoflagellates Photosynthetic, unicellular with flagella
Live in aquatic environments Some are luminescent Do not appear to be directly related to any other phylum “Red tide” are “blooms” – fish, birds, and marine mammals may die from toxins DNA not complexed with histones

30 General Structure

31 General Characteristics
Most are solitary Most have two flagella of unequal length Cellulose cell wall of plates; or naked Ceratium-blooms color water brown, have fish/septic odor

32 Ceratium

33 Red Tide

34 Red Tide In marine ecosystems, can cause paralytic shellfish poisoning (PSP) Gonyaulax tamarensis

35 Noctiluca, sea sparkle Pfisteria

36 Brown algae Not plants Conspicuous seaweeds of northern regions
Life cycle involves alternation of generations Sporophyte – multicellular and diploid Gametophyte – multicellular and haploid Not plants


38 Chlorophyta: Green Algae

39 Cladophora Branching filaments; often forms mats

40 Chloroplasts often distinctive to the genus
Spirogyra-spirals Mougeotia-plates; can orient Ulothrix-’apple core’ Zygnema-stellate

41 Flagellated forms Chlamydomonas Eudorina Pandorina Volvox

42 Euglena


44 Chrysophyta: Golden Browns
Eukaryotic Pigments: chlorophyll a & b, carotenoids, fucoxanthin Food storage: chrysolaminarin, oils Cell wall: cellulose One or two flagella may be present

45 Cluster of biflagellate cells
Golden brown (not green like similar looking green algae) No division of labor between cells

46 Vaucheria

47 Dinobryon Constructs a cellulose lorica
Diploid zygote can act as resting stage that can last for years Locally common

48 Factors affecting algal growth
Remember: they are plants! Amount of sunlight received: turbidity & water clarity require nutrients (fertilizers) P and N water temperature; some are seasonal; heat and chemistry sinking or flushing grazing competition from other plants for limited materials

49 Problems from Algae Aesthetics: who wants a scum-covered pond?
Reduces water clarity Taste and odor: from fish to pigsty Mats clog propellers and cost you lures! Swimming: aesthetics and safety Can form rotting masses: odor and oxygen problems

50 Monitoring Algae Note water color: Brown: diatoms
Bluish green: blue-greens e.g., Microcystis or Oscillatoria Bright green: Euglena-types, Volvox

51 Monitoring Algae (cont.)
Note water clarity: Microscopic ‘cut grass’ --->Aphanizomenon

52 Remember . . . some algae is desirable!
Types: Single-celled/phytoplankton diatoms, greens, blue-greens Colonial/phytoplankton Euglena, Volvox Filamentous Spirogyra, Oscillatoria

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