University of California, Santa Cruz
ALGAE OF
Name
• Midterm in one week (Monday, April 28)
Location
Chlorophyta, Cladophorales
Acrosiphonia coalita (Ruprect) R.F. Scagel, D.J .
Garbary, L.Golden & M.J.Hawkes
Davenport Landing , Santa Cruz, California
Habitat
found in low intertidal, growing on rocks
Collected by
your name
Date
April 19, 2014
Identified by
your name
Date
April 19, 2014
No.
1
• Format:
• Definitions
• Short Answer
• Ps/I Curve
• Dichotomous key
• Life History
• A couple of matching sections
• Short Essays
Heterokontophyt a Incertae sedis
Phaeostrophion irregulare Setchell & N.L. Gardner
Division: Heterokontophyta
Dichotomous Key: Cannot use names of
groups, instead characteristics
Example: Chlamydomonas, Dictyota, Halimeda
Has Chlorophyll C
Dictyota
Or
(Ochrophyta, Chromophyta, Phaeophyta)
No Chloropyll c
Forms palmelloid stage
Chlamydomonas
No palmelloid stage
Halimeda
~ 13,151 species
99% marine
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Groups (Kingdom)
DOMAIN
1.Bacteria- cyanobacteria (blue green algae)
2.Archae
3.Eukaryotes
Brief history of photosynthetic organisms on earth
3.45 bya = Cyanobacteria appear and introduce
photosynthesis
“Algae”
1. Alveolates- dinoflagellates
1.5 bya = first Eukaryotes appeared (nuclear envelope and ER
thought to come from invagination of plasma membrane)
2. Stramenopiles- diatoms, heterokonyophyta
0.9 bya = first multicellular algae (Rhodophyta - Red algae)
3. Rhizaria- unicellular amoeboids
800 mya = earliest Chlorophyta (Green algae)
4. Excavates- unicellular flagellates
400-500 mya = plants on land – derived from Charophyceae
5. Plantae- rhodophyta, chlorophyta, seagrasses
250 mya = earliest Heterokontophyta (Brown algae)
6. Amoebozoans- slimemolds
100 mya = earliest seagrasses (angiosperms)
7. Fungi- heterotrophs with extracellular digestion
8. Choanoflagellates- unicellular
9. Animals- multicellular heterotrophs
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Division: Heterokontophyta
Heterokontophyta Characteristics:
1) Pigments?
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***
2) Chloroplast structure?
3) Storage product?
*** We will focus on marine macroalgae
4) Flagella?
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Algal taxonomy
Phaeophyceae Metabolites:
Hierarchical system of classification:
Level:
Domain
Group
Division
Class
Order
Family
Genus
species
suffix:
-phyta
-phyceae
-ales
-aceae
Tannins (a.k.a. polyphenolic compounds) and terpenes
example:
Eukaryote
Stramenopiles
Heterokontophyta
Phaeophyceae
Laminariales
Lessoniaceae
Egregia
menziesii
- 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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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
Mannitol function
•important in osmoregulation - algae make more
mannitol to use up ions-> algal salinity decreases
•Storage products found in pyrenoids
•transporting organic material to different parts of
the thallus in large species
•lowers freezing point
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3
Phaeophyceae Flagella:
Phaeophyceae Thallus Morphology:
Heterokont flagella:
- Advanced forms: complex multicellular thalli
Anterior “flimmer flagellum”
•used for movement
• long flagellum with two rows of
stiff hairs (“mastigoneme”)
• directed forward
- 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)
Posterior “whiplash flagellum”
•used for steering
• short, smooth flagellum
• directed backward
• contains flavin which functions as
a photoreceptor
- Medullary cells  primarily for storage or transport
- Some browns quite large  over 40 meters long
• an eyespot acts a shading
structure or light reflector
Flagella attached laterally not apically
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Phaeophyceae Morphology of Cell Walls
Phaeophyceae Alginates:
Alginates = salt form of alginic acid; primarily in
intercellular matrix
Two main components:
1.
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Cellulose  microfibrils (1-10% of thallus dry weight)
Function: structural support
•Alginates = Alginic acid + an Ion
• Details of how alginates are used in helping ion
exchange are not well understood.
2. Alginic acid  surrounds the microfibrills (35% of thallus dry
weight)
Function: elasticity; flexibility; prevent desiccation; and
osmoregulation (ion exchange)
• 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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Algal life histories : Terminology
Phaeophyceae Alginates:
Sporophyte: diploid, 2n, multicellular release spores
Human uses for alginates 
- Ice-cream  prevents ice crystal formation
Sporangia = structure where spores are formed
- Frosting  water retaining properties; prevent drying
Spore (mitospore, meiospore): unicellular, must settle & grow, product
of mitosis(Mt) or meiosis (Me)
- Paints  emulsifying agent; keeps pigments suspended and
prevents brush streaking
- Pharmaceuticals
Gametophyte: hapliod, 1n, multicellular release gametes
- Food  “kombu” in Japan; dried and shredded laminarians
Gametangia = structure where gametes are formed
Gamete: unicellular, must fuse or die, product of mitosis(Mt) or
meiosis (Me)
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Phaeophyceae Reproduction:
Phaeophyceae Reproduction:
Gametangia = structure where gametes are formed
Functional Anisogamy
Sporangia = structure where spores are formed
uniseriate
Unilocular = all spores/gametes
are produced in a single compartment
“unangia”
How do the male gametes find the female ones?
multiseriate
Plurilocular = divided into
many small chambers
(locules); one spore/gamete
per chamber
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
“plurangia”
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Male gametes are VERY sensitive to pheromones: very low concentration will
elicit a response
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5
Phaeophyceae Reproduction:
Phaeophyceae habitat:
Functional Anisogamy
female gamete
• Mostly
male gamete
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
Browns are less diverse but more abundant
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Distinguishing among orders based on
Division: Heterokontophyta- 13,151 species
1. Life History and Reproduction
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
Isomorphic/heteromorphic alt. of gen.; diplontic
Isogamous, anisogamous, oogamous
2. Macrothallus Construction:
•
•
•
Filamentous
Parenchymatous
Pseudoparenchymatous
3. Growth
•
•
•
•
•
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Diffuse
Apical
Intercalary
Trichothallic
Meristodermal-a surface layer of cells (epidermis) that is
capable of dividing (is meristematic)
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6
Division: Heterokontophyta- 13,151 species
Order: Fucales
Class: Phaeophyceae – 1,836 species
1. Life History and Reproduction
Order: 19 orders but we will focus on 6
1. Fucales -529 species
- Usually saxicolous
- Unattached in some cases
- Unilocular gametangia
2. Macrothallus Construction:
Genus: Fucus
Silvetia
Pelvetiopsis
Sargassum
Cystoseira
3. Growth
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Life History of Fucales
Diplontic: 2N thallus, the gametes are the only
haploid stage
Receptacle
- swollen tips of fucoids where meiosis occurs
-
terminal portion of a branch bearing numerous
embedded conceptacles
Conceptacles
- chambers where the gametes are stored
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Conceptacles
Monoecious- having the male & female
reproductive structure borne on
the same individual plants
-one house
Oogonia- female reproductive cell
containing one or more egg (gamete)
Dioecious- having the male & female reproductive structure borne on
separate individual plants; said of the species
-two houses
Antheridia- a male reproductive structure
producing motile male gametes
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Fucus
Silvetia
Pelvetiopsis
Midrib
Playdough stipe
Flattened stipe
8 eggs per oogonium
2 eggs per oogonium
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Sargassum:
Sargasso Sea in the Atlantic
=Unattached Sargassum spp  rafts
1 egg per
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oogonium
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Cystoseira
Sargassum
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
-catenate series
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Division: Heterokontophyta- 13,151 species
Sargassum muticum
-singly
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Order: Ectocarpales:
Class: Phaeophyceae – 1,836 species
1. Life History and Reproduction:
Order: 19 orders but we will focus on 6
2. Ectocarpales-696 species
- Saxicolous or epiphytic
- Uniseriate filaments
- Opportunistic spp, excellent colonizers
-Female gametes releases pheromone
ectocarpene
2. Macrothallus Construction:
Genus: Ectocarpus
Haplogloia
3. Growth:
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Division: Heterokontophyta- 13,151 species
Life History of Ectocarpales:
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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Life History of Desmarestiales
Order: Desmarestiales
1. Life History and Reproduction:
2. Macrothallus Construction:
3. Growth
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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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