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Division: Ochrophyta

Division: Ochrophyta

Algal Evolution: Division: Or 3.9 bya = appear and introduce (Heterokontophyta, Chromophyta, Phaeophyta) 2.5 bya = appeared (nuclear envelope and ER thought to come from invagination of plasma membrane)

1.6 bya = Multicellular -Rhodophyta () &Chlorophyta (Green algae)

900 mya= & Invertebrates appear

490 mya = Phaeophyceae () & land & coralline algae & crustaceans & mulluscs

408mya= Insects & Fish

362 mya = & Amphibians & Reptiles ~ 16,999 species 99% marine 290mya- Gymnosperms

145 mya = & Angiosperms

DOMAIN Groups () Groups (Kingdom) 1.Bacteria- cyanobacteria (blue green algae) 1.Bacteria- cyanobacteria (blue green algae) 2.Archae 2.Archae “Algae” 3.Eukaryotes 3.Eukaryotes 1. - dinoflagellates, 1. Alveolates- dinoflagellates 2. - diatoms, ochrophyta 2. Stramenopiles- diatoms, ochrophyta 3. - unicellular amoeboids 3. Rhizaria- unicellular amoeboids 4. Excavates- unicellular 4. Excavates- unicellular flagellates 5. Plantae- rhodophyta, chlorophyta, seagrasses 5. Plantae- rhodophyta, chlorophyta, seagrasses 6. Amoebozoans- slimemolds 6. Amoebozoans- slimemolds 7. Fungi- heterotrophs with extracellular digestion 7. Fungi- heterotrophs with extracellular digestion 8. - unicellular 8. Choanoflagellates- unicellular

9. - multicellular heterotrophs 3 9. Animals- multicellular heterotrophs 4

1 DOMAIN Eukaryotes DOMAIN Eukaryotes

Chromista = 17,500 spp. derived from red algae Chromista = 17,500 spp. chloroplasts derived from red algae contains Alveolates & Stramenopiles according to Algaebase contains Alveolates & Stramenopiles according to Algaebase

Group Stramenopiles- 13,500 spp two unequal flagella, chloroplasts 4 Group Stramenopiles- 13,500 spp two unequal flagella, chloroplasts 4 membranes membranes Division Ochrophyta- 13, 235 spp. - many classes unicellular Division Ochrophyta- 13, 235 spp. diatoms & brown algae • class: Aurearenophyceae- 32 • class: Bacillariophyceae- 9657 pennate diatoms Class Phaeophyceae- 2059 spp. of brown algae • class: -14 Class Bacillariophyceae- 9659 spp. of pennate diatoms • class: Chrysophyceae- 595 Class - 2199 spp. of centric diatoms • class: Coscinodiscophyceae- 2199 centric diatoms • class: - 106 • class: Eustigmatophyceae- 36 • class: -785 • class: - 16 • class: Phaeophyceae-2059 brown algae • class: Picophagophyceae-4 • class: Placidiophyceae-2 • class: Raphidophyceae- 28 • class: Synurophyceae- 314 5 6 • class: Xanthophyceae- 557

Algal Ochrophyta Characteristics: Hierarchical system of classification: 1) Pigments? Level: suffix: example: Domain Eukaryota Group Chromista 2) structure? Division -phyta Ochrophyta Class -ppyhyceae Phaeoppyhyceae Order -ales Laminariales Family -aceae Genus 3) Storage product? species menziesii

4) Flagella? 2

2 Phaeophyceae Storage Products: Seawater is hypotonic (less saline) than most algal cells

•laminaran and mannitol are most abundant Phaeophyceae Storage Products : •Always sugars, never starch •Storage products found in pyrenoids Mannitol function •important in osmoregulation- algae make more mannitol to use up ions-> algal salinity decreases

•transporting organic material to different parts of the thallus in large species

•lowers freezing point

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Phaeophyceae Flagella: Phaeophyceae Metabolites: flagella: Tannins - polyphenolic compounds Anterior “flimmer ” Terpenes -aromatic hydrocarbons •used for movement • long flagellum with two rows of - Anti-endophyte, -epiphyte, and anti-herbivory stiff hairs (“mastigoneme”) •directed forward -Stored in special vesicles called physodes in the cytoplasm Posterior “whiplash flagellum” -May st rength ce ll wall s by int eracti ng with a lg ina tes •used for steering • short, smooth flagellum -Block UVB protecting algae from radiation damage •directed backward • contains flavin which functions as a photoreceptor

• an eyespot acts a shading structure or light reflector

Flagella attached laterally not apically 5 4

3 Phaeophyceae Thallus Morphology: Phaeophyceae Morphology of Cell Walls

- Advanced forms: complex multicellular thalli - Not unicellular (except gametes and spores) Two main components: - Simplest forms are branching filaments 1. Cellulose  microfibrils (1-10% of thallus dry weight) - More complex forms are parenchymatous and pseudoparenchymatous Function: structural support - Differentiation of cortex (outer pigmented cells) and medulla (inner non-pigmented cells) - Medullary cells  primarily for storage or transport 2. Alginic acid  surrounds the microfibrills (35% of thallus dry weight) - Some browns quite large  over 40 meters long Function: elasticity; flexibility; prevent desiccation; and osmoregulation (ion exchange)

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Phaeophyceae Alginates: Phaeophyceae Alginates: Alginates = salt form of alginic acid; primarily in  intercellular matrix Human uses for alginates -Ice-cream  prevents ice crystal formation •Alginates = Alginic acid + an Ion -Frosting  water retaining properties; prevent drying

• Details of how alginates are used in helping ion -Paints  emulsifyygging agent; keep ppgs pigments susp ended and exchange are not well underst ood . prevents brush streaking

• One proposed mechanism is that preferentially using -Pharmaceuticals some ions and not others helps to balance overall ion - Food  “kombu” in ; dried and shredded laminarians levels.

• Common ions that are used to make alginates are Ca, Na and Mg 8 8

4 Algal life histories : Terminology Phaeophyceae Reproduction: Gametangia = structure where gametes are formed

Sporophyte: diploid, 2n, multicellular release spores Sporangia = structure where spores are formed

Sporangia = structure where spores are formed

Spore (mitospore, meiospore): unicellular, must settle & grow, product of mitosis(Mt) or meiosis (Me)

Gametophyte: hapliod, 1n, multicellular release gametes uniseriate multiseriate Gametangia = structure where gametes are formed Unilocular = all spores/gametes Plurilocular = divided into are produced in a single compartment many small chambers Gamete: unicellular, must fuse or die, product of mitosis(Mt) or (locules); one spore/gamete meiosis (Me) “unangia” per chamber

“plurangia” 10

Phaeophyceae Reproduction: Phaeophyceae Reproduction:

Functional Anisogamy = Functional Anisogamy = look the same but have different behaviors look the same but have different behaviors

How do the male gametes find the female ones? female gamete male gamete

Pheromones = chemicals produced to elicit a specific behavioral or physiological response from another individual.

Many Phaeophyceans produce sexual pheromones, all are chemically similar (unsaturated hydrocarbons). Similarity  high cross-reactivity

Male gametes are VERY sensitive to pheromones: very low concentration will elicit a response 11 12

5 Division: Ochrophyta- 16,999 species Phaeophyceae habitat: Class: Phaeophyceae – 2,060 species

• Mostly marine (or at least brackish water) Order: 19 orders but we will focus on 6 • Intertidal and subtidal 1. -591 species 2. -787 species • Dominate colder waters 3. - 272 species Northern hemisphere: 4. - 35 species # of red species > # of brown species 5. Desmerestales- 29 species 6. Laminariales- 148 species # of red individuals << # of brown individuals

Browns are less diverse but more abundant

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Distinguishing among orders based on Division: Ochrophyta- 16,999 species 1. Life History and Reproduction • Isomorphic/heteromorphic alt. of gen.; diplontic Class: Phaeophyceae – 2,060 species • Isogamous, anisogamous, oogamous Order: 19 orders but we will focus on 6 2. Macrothallus Construction: 1. Fucales -591 species •Filamentous - Usually saxicolous • Parenchymatous •Pseudoppymarenchymatous - Unattached in some cases -Unilllocular gametangia 3. Growth Genus: • Diffuse •Apical •Intercalary Pelvetiopsis • Trichothallic • Meristodermal-a surface layer of cells (epidermis) that is capable of dividing (is meristematic) Stephanocystis

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6 Life History of Fucales Diplontic: 2N thallus, the gametes are the only Order: Fucales haploid stage

1. Life History and Reproduction

2. Macrothallus Construction:

3. Growth

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Receptacle Monoecious- having the male & female - swollen tips of fucoids where meiosis occurs reproductive structure borne on - terminal portion of a branch bearing numerous the same individual plants embedded conceptacles -one house

Dioecious- having the male & female reproductive structure borne on separate individual plants; said of the species Conceptacles -two houses - chambers where the gametes are stored

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7 Conceptacles Fucus Silvetia Pelvetiopsis Mid Mid- high High

Oogonia- female reproductive cell containing one or more egg (gamete)

Midrib Playdough stipe Flattened stipe

Antheridia- a male reproductive structure producing motile male gametes

1 egg per 29 8 eggs per oogonium 2 eggs per oogonium oogonium30

Sargassum: Sargassum Sargasso Sea in the Atlantic Stephanocystis

=Unattached Sargassum spp  rafts

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8 Pneumatocysts- Division: Ochrophyta- 16,999 species -a large float containing gas found in Ochrophyta Class: Phaeophyceae – 2,060 species -provide buoyancy to lift the blades toward the surface, allowing them to receive more sunlight for Ps Order: 19 orders but we will focus on 6 - can hold O2, CO2, CO 2. Ectocarpales-787 species - Saxicolous or epiphytic - Uniseriate filaments - Opportunistic spp, excell ent colonizers -Female gametes releases pheromone ectocarpene

Genus: Haplogloia Cystoseria osmundacea

-catenate series -singly 33 14

Life History of Ectocarpales: Order: Ectocarpales: Isomorphic Alternation of Generations

1. Life History and Reproduction:

2. Macrothallus Construction:

3. Growth:

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9 Haplogloia andersonnii – Division: Ochrophyta- 16,999 species heteromorphic alternation of generation diplohaplontic Class: Phaeophyceae – 2,060 species Order: 19 orders but we will focus on 6 Unangia ovoid 3. Dictyotales- 272 species - Saxicolous - Common in tropical waters; also found locall y subtid a l - Pheromone= dictyotene

Genus Padina

Gametophyte (1N)- microscopic disk

Sporophyte (2N) 14

Life history of Dictyota Order: Dictyotales • Reproductive structures in “sori” = cluster of gametangia or 1. Life History and Reproduction: sporangia

• Tetraspores (non-flagellated) released by 2N sporophyte

2. McrthllusMacrothallus Cnstructin:Construction: • Gametophyte dioecious

•Large egg  one per “oogonium” = female reproductive structure 3. Growth: containing one or more eggs

•Sperm  single hairy flagella but has second basal body 20 21

10 Life History of Dictyota: A Dictyota Story: (Stachowicz and Hay 2000) Isomorphic Alternation of Generations Cape Hatteras Local adaptation Associational defences

Southern Sites Northern Sites + Libinia dubia, the decorator crab + Libinia dubia, the decorator crab + Dictyota menstrualis, + No chemically noxious the chemically algae defended brown alga (diterpenes) + Carnivorous fishes + Omnivorous fishes + Crabs are specialists + Crabs are generalists in decoration in decoration 17 preference preference 21

The only calcified Phaeophycean: Padina Division: Ochrophyta- 16,999 species Class: Phaeophyceae – 2,060 species Order: 19 orders but we will focus on 6 4. Ralfsiales- 35 species - Saxicolous or epiphytic - Common intertidally, tropics to poles -crusto se in a t lea st one life history stage Increased Grazing Genus: Ralfsia

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11 Order: Ralfsiales -perennial crustose base up to 5cm with erect axes that die back in the fall 1. Life History and Reproduction:

2. MhllMacrothallus CCionstruction: Ralfsia

3. Growth:

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Division: Ochrophyta- 16,999 species Order: Class: Phaeophyceae – 2,060 species Order: 19 orders but we will focus on 6 1. Life History and Reproduction: 5. Desmerestailes- 29 species - Saxicolous - Low intertidal to subtidal - “d“Acid weed” 2. Macrothallus Construction: Genus

3. Growth

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12 - Morphology variable within the genus Life History of Desmarestiales -Subtidal, but grows well in high light (very abundant if disturbance has removed other plants or canopy, e.g. El Nino, or urchin grazing) - Disappears with growth due to canopy cover; shading

- ”Acid weed”: cells accumulate sulfate ions from seawater which reacts with water to produce sulfuric acid or malic acid, stored in vacuoles =ANTIHERBIVORY, pH 0.8-1.8, bleaches other algae

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