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University of California, Santa Cruz

ALGAE OF Chlorophyta , Cladophorales

Name Acrosiphonia coalita (Ruprect) R.F. Scagel, D.J .

Garbary, L.Golden & M.J.Hawkes

Location Davenport Landing , Santa Cruz, California

Habitat found in low intertidal, growing on rocks

Collected by your name Date April 19, 2014 No. 1

Identified by your name Date April 19, 2014

Heterokontophyta Incertae sedis

Phaeostrophion irregulare Setchell & N.L. Gardner

• Midterm in one week (Monday, April 28) • Format:

• Definitions • Short Answer • Ps/I Curve • Dichotomous key • Life History • A couple of matching sections • Short Essays

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Dichotomous Key: Cannot use names of groups, instead characteristics Example: Chlamydomonas, Dictyota, Halimeda

Has Chlorophyll C Dictyota

No Chloropyll c

Forms palmelloid stage Chlamydomonas

No palmelloid stage Halimeda

Division: Heterokontophyta Or

(Ochrophyta, Chromophyta, Phaeophyta)

~ 13,151 species 99% marine

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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 250 mya = earliest Heterokontophyta (Brown algae) 100 mya = earliest seagrasses (angiosperms)

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DOMAIN 1.Bacteria- cyanobacteria (blue green algae)

2.Archae 3.Eukaryotes

Groups (Kingdom) 1. Alveolates- dinoflagellates 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 9. Animals- multicellular heterotrophs

“Algae”

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Heterokontophyta Characteristics:

1) Pigments?

2) Chloroplast structure?

3) Storage product?

4) Flagella?

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Division: Heterokontophyta

Many classes, mostly unicellular or colony of unicells: • class: Chrysophyceae • class: Synurophyceae • class: Dictyochophyceae • class: Pelagophyceae • class: Raphidophyceae • class: Xanthophyceae • class: Eustigmatophyceae • class: Tribophyceae • class: Phaeothamniophyceae • class: Phaeophyceae***

*** We will focus on marine macroalgae

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Hierarchical system of classification: Level: suffix: example: Domain Eukaryote Group Stramenopiles Division -phyta Heterokontophyta Class -phyceae Phaeophyceae Order -ales Laminariales Family -aceae Lessoniaceae Genus Egregia species menziesii

Algal taxonomy

Phaeophyceae Metabolites:

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Tannins (a.k.a. polyphenolic compounds) and terpenes

- Anti-endophyte, -epiphyte, and anti-herbivory

-Stored in special vesicles called physodes in the cytoplasm

-May strength cell walls by interacting with alginates

-Block UVB protecting algae from radiation damage

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•laminaran and mannitol are most abundant

•Always sugars, never starch

•Storage products found in pyrenoids

Phaeophyceae Storage Products:

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Phaeophyceae Storage Products :

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

Seawater is hypotonic (less saline) than most algal cells

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Heterokont flagella: Anterior “flimmer flagellum” •used for movement • long flagellum with two rows of stiff hairs (“mastigoneme”) • directed forward Posterior “whiplash flagellum” •used for steering • short, smooth flagellum • directed backward • contains flavin which functions as a photoreceptor • an eyespot acts a shading structure or light reflector

Phaeophyceae Flagella:

Flagella attached laterally not apically 5

- Advanced forms: complex multicellular thalli

- Not unicellular (except gametes and spores)

- Simplest forms are branching filaments

- More complex forms are parenchymatous and pseudoparenchymatous

- Differentiation of cortex (outer pigmented cells) and medulla (inner non-pigmented cells)

- Medullary cells primarily for storage or transport

- Some browns quite large over 40 meters long

Phaeophyceae Thallus Morphology:

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Phaeophyceae Morphology of Cell Walls

Two main components: 1. Cellulose microfibrils (1-10% of thallus dry weight)

Function: structural support

2. Alginic acid surrounds the microfibrills (35% of thallus dry weight) Function: elasticity; flexibility; prevent desiccation; and

osmoregulation (ion exchange)

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Phaeophyceae Alginates:

Alginates = salt form of alginic acid; primarily in intercellular matrix

•Alginates = Alginic acid + an Ion

• Details of how alginates are used in helping ion exchange are not well understood.

• One proposed mechanism is that preferentially using some ions and not others helps to balance overall ion levels.

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

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Phaeophyceae Alginates:

Human uses for alginates

- Ice-cream prevents ice crystal formation

- Frosting water retaining properties; prevent drying

- Paints emulsifying agent; keeps pigments suspended and prevents brush streaking

- Pharmaceuticals

- Food “kombu” in Japan; dried and shredded laminarians

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Algal life histories : Terminology

Sporophyte: diploid, 2n, multicellular release spores 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 Gametangia = structure where gametes are formed Gamete: unicellular, must fuse or die, product of mitosis(Mt) or meiosis (Me)

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Unilocular = all spores/gametes are produced in a single compartment “unangia”

Plurilocular = divided into many small chambers (locules); one spore/gamete per chamber “plurangia”

Gametangia = structure where gametes are formed Sporangia = structure where spores are formed

Phaeophyceae Reproduction:

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uniseriate multiseriate

How do the male gametes find the female ones?

Phaeophyceae Reproduction:

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

Functional Anisogamy

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Phaeophyceae Reproduction:

female gamete male gamete

Functional Anisogamy

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Phaeophyceae habitat:

• Mostly marine (or at least brackish water)

• Intertidal and subtidal

• Dominate colder waters

Northern hemisphere:

# of red species > # of brown species

# of red individuals << # of brown individuals

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Browns are less diverse but more abundant

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Division: Heterokontophyta- 13,151 species

Class: Phaeophyceae – 1,836 species

Order: 19 orders but we will focus on 6 1. Fucales -529 species 2. Ectocarpales-696 species 3. Desmerestailes- 26 species 4. Dictyotales- 242 species 5. Ralfsiales- 54 species 6. Laminariales- 129 species

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Distinguishing among orders based on

1. Life History and Reproduction • Isomorphic/heteromorphic alt. of gen.; diplontic • Isogamous, anisogamous, oogamous

2. Macrothallus Construction: • Filamentous • Parenchymatous • Pseudoparenchymatous

3. Growth • Diffuse • Apical • Intercalary • Trichothallic • Meristodermal-a surface layer of cells (epidermis) that is

capable of dividing (is meristematic)

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Division: Heterokontophyta- 13,151 species

Class: Phaeophyceae – 1,836 species

Order: 19 orders but we will focus on 6 1. Fucales -529 species Genus: Fucus Silvetia Pelvetiopsis Sargassum Cystoseira

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- Usually saxicolous - Unattached in some cases - Unilocular gametangia

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Order: Fucales

1. Life History and Reproduction

2. Macrothallus Construction:

3. Growth

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

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Conceptacles - chambers where the gametes are stored

Receptacle

- swollen tips of fucoids where meiosis occurs - terminal portion of a branch bearing numerous embedded conceptacles

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

Conceptacles

Antheridia- a male reproductive structure producing motile male gametes

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Monoecious- having the male & female reproductive structure borne on the same individual plants -one house

Dioecious- having the male & female reproductive structure borne on separate individual plants; said of the species -two houses

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Fucus Silvetia Pelvetiopsis

Midrib Playdough stipe Flattened stipe

8 eggs per oogonium 2 eggs per oogonium 1 egg per oogonium

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Sargasso Sea in the Atlantic

=Unattached Sargassum spp rafts

Sargassum:

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Cystoseira Sargassum

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Pneumatocysts- -a large float containing gas found in heterokontophyta

-provide buoyancy to lift the blades toward the surface,

allowing them to receive more sunlight for Ps

- can hold O2, CO2, CO

Cystoseria osmundacea Sargassum muticum -catenate series -singly

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Division: Heterokontophyta- 13,151 species

Class: Phaeophyceae – 1,836 species

Order: 19 orders but we will focus on 6 2. Ectocarpales-696 species

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- Saxicolous or epiphytic - Uniseriate filaments - Opportunistic spp, excellent colonizers -Female gametes releases pheromone ectocarpene

Genus: Ectocarpus Haplogloia

Order: Ectocarpales:

1. Life History and Reproduction:

2. Macrothallus Construction:

3. Growth:

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Life History of Ectocarpales:

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Division: Heterokontophyta- 13,151 species

Class: Phaeophyceae – 1,836 species

Order: 19 orders but we will focus on 6 3. Desmerestailes- 26 species - Saxicolous - Low intertidal to subtidal - “Acid weed”

Genus Desmarestia

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Order: Desmarestiales

1. Life History and Reproduction:

2. Macrothallus Construction:

3. Growth

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Life History of Desmarestiales

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- Morphology variable within the genus

-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 kelp 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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