Marine botany – Algae– the study of aquatic plants and algae that live in seawater convenience term encompassing various distinctly related of the open ocean and the littoral zone and in brackish groups of aquatic photsynthetic eukaryoes waters of estuaries Phycology- study of algae Macroalgae - Rhodophyta, Chlorophyta, Heterokontophyt a alga (singular) : “I study Silvetia, the intertidal alga” Microalgae (Phytoplankton) - Bacillariophyta, Dinophyta , Haptophyta algae (plural): “Algae rock my world” algal (adj.): Algal lunch, algal skirt, algal growth rate Angiosperms algaes (wrong!) -Mangroves, Marsh Plants, Seagrasses “ ” Cyanobacteria 1 2 I. What are algae? I. What are algae? • Polyphyletic group = different ancestors, different evolutionary histories A B C D E A B C D E A B C D E A B C D E monophyletic polyphyletic paraphyletic or clade 3 4 1 Eukaryote Groups DOMAIN Groups (Kingdom) 1.Bacteria- cyanobacteria 2.Archae Alveolates- dinoflagellates 3.Eukaryotes 1. Alveolates- unicellular,plasma membrane supported by Stramenopiles- diatoms, heterokonyophyta flattened vesicles Rhizaria 2. Stramenopiles- two unequal flagella, chloroplasts 4 Excavates membranes 3. Rhizaria- unicellular amoeboids Plantae- rhodophyta, chlorophyta, seagrasses Amoebozoans 4. Excavates- unicellular flagellates Fungi 5. Plantae- most broadly defined plant group Choanoflagellates Animals 6. Amoebozoans- pseudopods for movement & eating 7. Fungi- heterotrophs with extracellular digestion 8. Choanoflagellates- unicellular withsingle flagella 5 9. Animals- multicellular heterotrophs 6 DOMAIN Groups (Kingdom) 1.Bacteria- cyanobacteria (blue green algae) Defining characteristics of Algae: 2.Archae “Algae” Photosynthesis (photoautotrophic, usually), using Chl a as 3.Eukaryotes 1. Alveolates- dinoflagellates primary pigment 2. Stramenopiles- diatoms, heterokonyophyta BUT: Limited cellular differentiation compared to 3. Rhizaria- unicellular amoeboids terrestrial plants 4. Excavates- unicellular flagellates No “real” vascular system 5. Plantae- rhodophyta, chlorophyta, seagrasses Sex organs unicellular, or all cells capable of reproduction (no sterile layer of cells 6. Amoebozoans- slimemolds surrounding sex organs aka NO FLOWERS) 7. Fungi- heterotrophs with extracellular digestion Much greater diversity of photosynthetic pigments 8. Choanoflagellates- unicellular and life histories 9. Animals- multicellular heterotrophs 7 8 2 Algae show tremendous diversity of A Vascular plant An Alga form, habitat, and lifestyle flower sorus blade stem photo Pete Dal Ferro stipe leaf holdfast roots Thallophyte- plants that lack roots, stems & leaves 9 10 Free-living and unattached Red tides = dinoflagellates like Lingulodinium polyedrum (“planktonic”) Unattached macroalgae- Rhodoliths (“benthic” = bottom dwelling) photo: M organ Bond Found in all bodies of water (freshwater, marine intertidal and subtidal) as well as terrestrial systems with enough moisture11 12 3 Free-living and attached to the substrate Parasitic Epiphytic Postelsia palmaeformis “saxicolous”, or “saxiphytic” Smithora naiadum on Phyllospadix torreyi Caulerpa taxifolia “psammophtyic” Trentepohlia on 13 Monterey Cypress 14 Symbiotic and Endoymbiotic Ecological importance of algae Lichen = close association of an alga and a fungus - Primary production; role in species interactions - Ecosystem engineers: e.g. kelp forests, rhodolith beds, coral Marine: Zooxanthellae in corals, anemonies, reefs = Create structure that defines the habitat type nudibranchs, flatworms Radiolarians, Foramaniferans = ameoba + alga fH2O too!: Zoochlorellae in hydras, sponges, etc.15 16 4 - Nutrient input into terrestrial systems (“Allochthonous input”); just Direct importance of algae to human beings beginning to appreciate this Origin’s of the world’s oil supplies (dinoflagellates,coccolithophores,diatoms) Used in biological and medical research (e.g. Cyanobacteria, Chlamydomonas; fucoids); One product of red algae (e.g. Gelidium, Gigartina) = agar; produces gel at low temperatures, used in gel electrophoresis. (HUGE in genetics) Eaten “as itself” (e.g. nori, Spirulina) Products of algae are everywhere: carrageenan (from red algae) and alginates (from brown algae, e.g. Macrocystis, Laminaria) from polysaccharides in cell walls, act as thickening agents Ice cream, mayonnaise, chocolate milk, soy milk, toothpaste, salad dressings, shaving cream, fertilizers, rubber, paint, hair products 17 18 II. Algal taxonomy II. Algal taxonomy Hierarchical system of classification: Hierarchical system of classification: Level: suffix: Level: suffix: example: Domain Domain Eukaryote Kingdom/Group Kingdom/Group Plantae Phylum/Division -phyta Phylum/Division -phyta Chlorophyta Class -phyceae Class -phyceae Ulvophyceae Order -ales Order -ales Ulvales Family -aceae Family -aceae Ulvaceae Genus Genus Ulva species species fenestrata • King Phillip Came Over For Good Spaghetti • Keep Dishes Clean Or Family Gets Sick 19 20 5 II. Algal taxonomy - Nomenclature acknowledges the first and last Hierarchical system of classification: person to describe the species Level: suffix: example: Domain Eukaryote for example: Linnaeus called this Fucus pyriferus; Kingdom/Group Stramenopiles later renamed Macrocystis pyrifera by Carl Adardh, Phylum/Division -phyta Heterokontophyta so: Class -phyceae Phaeophyceae Order -ales Laminariales Macrocystis pyrifera (Linnaeus) Adardh Family -aceae Alariaceae Genus Egregia species menziesii 21 22 1753, Linneaus divided all life into two Phyla = Division % marine ~# species Plants and Animals Cyanophyta (blue-green algae) 8 2,000 Rhodophyta (red algae) 98 6,000 Within the plants, he recognized Chlorophyta (green algae) 13 16,000 • Cryptogams – hidden gametes…land plants Heterokontophyta (brown algae) 99 1,500 • Thallogams – unspecialized gametes … the algae Bacillariophyta (diatoms) 50 10,000 Dinophyta (dinoflagellates) 90 2,000 Only three genera originally recognized: Bryophyta Fucus-fleshy Mosses, liverworts 0 25,000 Ulva- membranous Conferva- filamentous Vascular plants Ferns, horsetail, club moss 0.1 13,018 Gymnosperms 0 722 Angiosperms 0.09 285,000 23 24 6 -Taxonomy/systematics constantly under revision Division % marine ~# species # in Ca Cyanophyta (blue-green algae) 8 2,000 - Depending on who you ask, between 50,000 and Rhodophyta (red algae) 98 6,000 459 Chlorophyta (green algae) 13 16,000 72 10 million different algal spp! Heterokontophyta (brown algae) 99 1,500 137 Bacillariophyta (diatoms) 50 10,000 Dinophyta (dinoflagellates) 90 2,000 - Biological species concept? Bryophyta Mosses, liverworts 0 25,000 -Morphology? Vascular plants Ferns, horsetail, club moss 0.1 13,018 Gymnosperms 0 722 - Genetics? Angiosperms 0.09 285,000 25 26 Mastocarpus papillatus Petrocelis Mastocarpus papillatus + 2N 2N ‘Petrocelis’ crust (sporophyte) 1N 27 1N fronds 28 (gametophytes) 7 III. Algal evolution Endosymbiotic theory of organelle acquisition: (L. Margolis) Brief history of photosynthetic organisms on earth - Heterotrophic eukaryote eats 3.45 bya = Cyanobacteria appear and introduce heterotrophic bacteria lead to the photosynthesis formation of mitochondria 1.5 bya = first Eukaryotes appeared (nuclear envelope and ER thought to come from invagination of plasma membrane) -Heterotrophic eukaryote eats a photosynthetic bacteria (cyanobacteria) lead to the formation 0.9 bya = first multicellular algae (Rhodophyta - Red algae) of a chloroplast 800 mya = earliest Chlorophyta (Green algae) -Bacteria not digested but becomes 400-500 mya = plants on land – derived from Charophyceae an organelle 250 mya = earliest Heterokontophyta (Brown algae) Support of Endosymbiotic Theory 100 mya = earliest seagrasses (angiosperms) -Genetic material of the inner membrane 29 30 Primary Endosymbiosis: Secondary endosymbiotic events 1. Heterotrophic eukaryote eats photosynthetic bacteria 1. Heterotrophic eukaryote eats (cyanobacterium). photosynthetic eukaryote 2. Results in photosynthetic eukaryote. 2. Nucleus from photosynthetic Chloroplast has 2 membranes eukaryote is lost 3. Chloroplast ends up with 4 membranes 31 32 8 Secondary endosymbiotic events Secondary Endosymbiosis: 1. Heterotrophic eukaryote eats 1. Heterotrophic eukaryote eats photosynthetic eukaryote photosynthetic eukaryote 2. Nucleus from photosynthetic 2. Nucleus from photosynthetic eukaryote is lost eukaryote is lost 3. Chloroplast ends up with 4 3. Results in photosynthetic eukaryote. membranes Chloroplast has 4 membranes. Tertiary endosymbiotic events in some groups 33 34 Details of Endosymbiotic origins - Loss of plastids What is agreed upon: e.g. Parasitic algae on seaweeds: no pigments, all white • Each algal division is a ? Plocamiocolax = Parasite on Rhodophyte alga Plocamium monophyletic group • Reds and Greens – 1 event-2 membranes • Browns – 2 events- 4 membranes Plocamiocolax on Plocamium Plocamium Adapted From Palmer 2003 35 36 9 Three main divisions (phyla) of seaweeds: - Loss of plastids e.g. Heterotrophic algae Chlorophyta: Toxoplasma gondii = parasite in mammal muscular tissues 1 endosymbiotic event = 2 plastid membranes - Apicomplexan, closely related to dinoflagellates ~800 mya ~16,000 species; 1,300 are marine (most are fH2O) Heterokontophyta: 2 endosymbiotic events = 4 plastid membranes ~250 mya ~1,500 species; most are marine Rhodophyta: 1 endosymbiotic event = 2 plastid membranes ~0.9 bya ~60% of domestic cats are infected; ~6,000 species; 5,800 marine toxoplasmosis in pregnant women… caused by an alga! 37 38 Paper Discussion on wednesday: Lubchenco and Cubit. 1980. Heteromorphic life histories of certain marine algae as adaptations to variations in herbivory. Ecology 61(3): 676-687 Abstract Introduction Graphs & Figures Methods Results Discussion Sign up for paper you would like to lead. 39 40 10 .