Marine botany the study of aquatic plants and algae that live in seawater of the open ocean and the littoral zone and in brackish waters of estuaries Macroalgae - Rhodophyta, Chlorophyta, Heterokontophyt a Microalgae (Phytoplankt on) - Bacillariophyta, Dinophyta, Haptophyta Angiosperms -Mangroves, Marsh Plants, Seagrasses Algae convenience term encompassing various distinctly related groups of aquatic photsynthetic eukaryoes Phycology- study of algae alga (singular) : I study Silvetia, the intertidal alga algae (plural): Algae rock my world algal (adj.): Algal lunch, algal skirt, algal growth rate algaes (wrong!) 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 Alveolates- dinoflagellates Stramenopiles- diatoms, heterokonyophyta Rhizaria Excavates Plantae- rhodophyta, chlorophyta, seagrasses Amoebozoans Fungi Choanoflagellates Animals DOMAIN Groups (Kingdom) 1.Bacteria- cyanobacteria 2.Archae 3.Eukaryotes 1. Alveolates- unicellular,plasma membrane supported by flattened vesicles 2. Stramenopiles- two unequal flagella, chloroplasts 4 membranes 3. Rhizaria- unicellular amoeboids 4. Excavates- unicellular flagellates 5. Plantae- most broadly defined plant group 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) 2.Archae 3.Eukaryotes 1. Alveolates- dinoflagellates Algae Defining characteristics of Algae: Photosynthesis (photoautotrophic, usually), using Chl a as primary pigment 2. Stramenopiles- diatoms, heterokonyophyta 3. Rhizaria- unicellular amoeboids 4. Excavates- unicellular flagellates 5. Plantae- rhodophyta, chlorophyta, seagrasses 6. Amoebozoans- slimemolds 7. Fungi- heterotrophs with extracellular digestion 8. Choanoflagellates- unicellular BUT: Limited cellular differentiation compared to terrestrial plants No real vascular system Sex organs unicellular, or all cells capable of reproduction (no sterile layer of cells surrounding sex organs aka NO FLOWERS) Much greater diversity of photosynthetic pigments and life histories 9. Animals- multicellular heterotrophs 7 8 2
A Vascular plant An Alga Algae show tremendous diversity of form, habitat, and lifestyle flower stem sorus blade photo Pete Dal Ferro leaf roots stipe holdfast 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 moisture 11 12 3
Free-living and attached to the substrate Epiphytic Parasitic Postelsia palmaeformis saxicolous, or saxiphytic Smithora naiadum on Phyllospadix torreyi Caulerpa taxifolia psammophtyic 13 Trentepohlia on Monterey Cypress 14 Symbiotic and Endoymbiotic Lichen = close association of an alga and a fungus Marine: Zooxanthellae in corals, anemonies, nudibranchs, flatworms Ecological importance of algae - Primary production; role in species interactions - Ecosystem engineers: e.g. kelp forests, rhodolith beds, coral reefs = Create structure that defines the habitat type Radiolarians, Foramaniferans = ameoba + alga fh2o too!: Zoochlorellae in hydras, sponges, etc. 15 16 4
- Nutrient input into terrestrial systems ( Allochthonous input ); just beginning to appreciate this Direct importance of algae to human beings 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 17 Ice cream, mayonnaise, chocolate milk, soy milk, toothpaste, salad dressings, shaving cream, fertilizers, rubber, paint, hair products 18 II. Algal taxonomy Hierarchical system of classification: II. Algal taxonomy Hierarchical system of classification: Level: Domain Kingdom/Group Phylum/Division Class Order Family Genus species suffix: -phyta -phyceae -ales -aceae Level: suffix: example: Domain Eukaryote Kingdom/Group Plantae Phylum/Division -phyta Chlorophyta Class -phyceae Ulvophyceae Order -ales Ulvales Family -aceae Ulvaceae Genus Ulva species fenestrata King Phillip Came Over For Good Spaghetti Keep Dishes Clean Or Family Gets Sick 19 20 5
II. Algal taxonomy Hierarchical system of classification: Level: suffix: example: Domain Eukaryote Kingdom/Group Stramenopiles Phylum/Division -phyta Heterokontophyta Class -phyceae Phaeophyceae Order -ales Laminariales Family -aceae Alariaceae Genus Egregia species menziesii - Nomenclature acknowledges the first and last person to describe the species for example: Linnaeus called this Fucus pyriferus; later renamed Macrocystis pyrifera by Carl Adardh, so: Macrocystis pyrifera (Linnaeus) Adardh 21 22 1753, Linneaus divided all life into two Phyla = Plants and Animals Within the plants, he recognized Cryptogams hidden gametes land plants Thallogams unspecialized gametes the algae Only three genera originally recognized: Fucus-fleshy Ulva- membranous Conferva- filamentous Division % marine ~# species Cyanophyta (blue-green algae) 8 2,000 Rhodophyta (red algae) 98 6,000 Chlorophyta (green algae) 13 16,000 Heterokontophyta (brown algae) 99 1,500 Bacillariophyta (diatoms) 50 10,000 Dinophyta (dinoflagellates) 90 2,000 Bryophyta Mosses, liverworts 0 25,000 Vascular plants Ferns, horsetail, club moss 0.1 13,018 Gymnosperms 0 722 Angiosperms 0.09 285,000 23 24 6
Division % marine ~# species # in Ca Cyanophyta (blue-green algae) 8 2,000 Rhodophyta (red algae) 98 6,000 459 Chlorophyta (green algae) 13 16,000 72 Heterokontophyta (brown algae) 99 1,500 137 Bacillariophyta (diatoms) 50 10,000 Dinophyta (dinoflagellates) 90 2,000 Bryophyta Mosses, liverworts 0 25,000 Vascular plants Ferns, horsetail, club moss 0.1 13,018 Gymnosperms 0 722 Angiosperms 0.09 285,000 -Taxonomy/systematics constantly under revision - Depending on who you ask, between 50,000 and 10 million different algal spp! - Biological species concept? -Morphology? - Genetics? 25 26 Mastocarpus papillatus Petrocelis Mastocarpus papillatus 2N Petrocelis crust (sporophyte) + 2N 1N 27 1N fronds (gametophytes) 28 7
III. Algal evolution Brief history of photosynthetic organisms on earth 3.45 bya = Cyanobacteria appear and introduce photosynthesis 1.5 bya = first Eukaryotes appeared (nuclear envelope and ER thought to come from invagination of plasma membrane) 0.9 bya = first multicellular algae (Rhodophyta - Red algae) 800 mya = earliest Chlorophyta (Green algae) 400-500 mya = plants on land derived from Charophyceae Endosymbiotic theory of organelle acquisition: (L. Margolis) - Heterotrophic eukaryote eats heterotrophic bacteria lead to the formation of mitochondria -Heterotrophic eukaryote eats a photosynthetic bacteria (cyanobacteria) lead to the formation of a chloroplast -Bacteria not digested but becomes an organelle 250 mya = earliest Heterokontophyta (Brown algae) 100 mya = earliest seagrasses (angiosperms) 29 Support of Endosymbiotic Theory -Genetic material of the inner membrane 30 Primary Endosymbiosis: Secondary endosymbiotic events 1. Heterotrophic eukaryote eats photosynthetic bacteria (cyanobacterium). 1. Heterotrophic eukaryote eats photosynthetic eukaryote 2. Results in photosynthetic eukaryote. Chloroplast has 2 membranes 2. Nucleus from photosynthetic eukaryote is lost 3. Chloroplast ends up with 4 membranes 31 32 8
Secondary endosymbiotic events Secondary Endosymbiosis: 1. Heterotrophic eukaryote eats photosynthetic eukaryote 2. Nucleus from photosynthetic eukaryote is lost 3. Chloroplast ends up with 4 membranes 1. Heterotrophic eukaryote eats photosynthetic eukaryote 2. Nucleus from photosynthetic eukaryote is lost 3. Results in photosynthetic eukaryote. Chloroplast has 4 membranes. Tertiary endosymbiotic events in some groups 33 34 Details of Endosymbiotic origins? What is agreed upon: Each algal division is a monophyletic group Reds and Greens 1 event-2 membranes Browns 2 events- 4 membranes - Loss of plastids e.g. Parasitic algae on seaweeds: no pigments, all white Plocamiocolax = Parasite on Rhodophyte alga Plocamium Adapted From Palmer 2003 35 Plocamiocolax on Plocamium Plocamium 36 9
- Loss of plastids e.g. Heterotrophic algae Toxoplasma gondii = parasite in mammal muscular tissues - Apicomplexan, closely related to dinoflagellates Three main divisions (phyla) of seaweeds: Chlorophyta: 1 endosymbiotic event = 2 plastid membranes ~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 ~60% of domestic cats are infected; Rhodophyta: 1 endosymbiotic event = 2 plastid membranes ~0.9 bya ~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