Marine Plants:

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Marine Plants Algae
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Algal Taxonomy
Eukaryotic Algae Protists single celled, possess
nuclear membrane, aquatic photoautotrophs
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• CLASSIFICATION
• Algae are classified into Seven Phyla based on
• Color
• Type of Chlorophyll
• Form of Food Storage Substance
• Cell Wall Composition

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Dinoflagellates Diatoms Chlorophyta (green
algae) Phaeophyta (brown algae) Rhodophyta (red
algae)
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Photosynthetic pigments of marine plants

• 3 groups of photosynthetic pigments
• Actual photosynthetic pigment-
• 1. chlorophylls
• Accessory pigments-
• 2. caretenoids
• 3. phycoblins
• both caretenoids and phycoblins can function as
• accessory pigments
• part of light reaction or as donors of light
  energy to chlorophyll a
•  

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• Chlorophylls a, b, c, d, e.
• Each molecule functions at
• specific wavelengths of light.
•  
• 2. Carotenes
• carotene B- found in all three divisions
• xanthophylls- 20 different types of pigments and
  two types
• fucoxanthin- found only in phaeophyta
• lutein- common pigment in all large algae
•  
• 3. Phycoblins
• phycocyanin- blue pigment
• phycorethrin- pink-red pigment found in
  rhodophyta and
• cyanobacteria

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Dinoflagellata

• Single-celled eukaryote
• Animal/plant type organism with 2 flagella
• Bioluminescence
• Zooxanthellae Symbiodinium
• Pigments
• chlorophyll a and c
• carotenoids
• xanthophylls

Ceratium Gonyaulax
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Red Tide
PSP (paraletic shellfish poisoning)
Gonyaulax polyhedra, Gymnodium
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Biomagnification
Tertiary consumers
13.8 ppm
Secondary consumers
2.07 ppm
Primary consumers
0.23 ppm
Primary producers
0.04 ppm
The numbers are representative values of the
concentration in the tissues of dinoflagellate
toxin (ppm)
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Bacillariophyta (Diatoms)
Thecate- with shell Athecate- naked
2 kinds centric (circular) and penate (oblong)
Frustule (silica shell)
pennate
centric

• Pigments
• chlorophylls a and c
• carotenoids
• fucoxanthin

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Diatom Reproduction- asexual
epithecate
hypothecate
auxospore
Discards shell and grows new one
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Chlorophyta (green algae)

• Closely related to vascular plants
• Pigments
• chlorophyll a b
• carotenoids
• Unicellular, colonial, and multicellular
• Freshwater, brackish, and saltwater habitats
• Large in Hawaii
• Seaweeds- limu

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Chlorophyta Green Algae
Codium edule
Caulerpa racemosa
Dictyosphaeria cavernosa
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Life cycle of Ulva A Large Marine Green Algae
M E I O S I S
spores
haploid stage
spores germinate
diploid stage
sporophyte
gametophytes
F E R T I L I Z A T I O N
zygote
female
fused gametes
germinating zygote
gametes
male
the cycle begins again
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Phaeophyta (brown algae)

• Photosynthetic pigments
• chlorophyll a c
• carotenoids
• xanthophylls (e.g. fucoxanthin).
• All are multicellular
• Occupy marine environments.
• Hawaii Near shore marine environment

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Phaeophyta Brown Algae
Hydroclathrus clathratus
Sargassum echinocarpum
Sargassum polyphyllum
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Rhodophyta (red algae)
Photosynthetic Pigments chlorophyll
a carotenoids phycobilins. Mostly
multicellular, marine forms. Abundant in warm,
tropical coastal waters. Not all are red in
color
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Rhodophyta Red Algae
Asparagopsis taxiformis
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Food Source in Hawaii
There are about 600 different species in Hawaii
Limu were very important to early Hawaiians. More
than 70 different kinds were used eaten fresh,
blended with other foods, used as spices, used as
medicines, and even used in special religious
ceremonies. Today, many Hawaiian residents still
harvest fresh limu for food or buy it at the
market.  
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Algal Products

• Thickener and help smooth
• Many foods and milk-products

Certain alga can be used to make agar or as
stabilizer in gelatin and ice cream Use sugar,
milk, irish moss or euchima, Chondrus, Porphyra
and Rhodymenia- blend and boil.

• Toothpaste
• Beauty creams
• Paints
• Medical products- like bacterial culture plates,
  time-release pills, and dental impression gels

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Herbivores
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Algal Invaders
Acanthophora
Gracilaria
Hypnea

Avrainvillae
Kappaphycus
Eucheuma
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• Intrinsic Factors Controlling Algal Dominance in
  Invasive species
• high growth rates
• reproduce sexually and asexually
• high spore production
• effective vegetative propagation
• successful epiphytisim
• morphological plasticity
• diverse strategies in nutrient acquisition
• Extrinsic Factors Controlling Algal Dominance
• Invasive algae are released from natural
  predators or subjected to a lower abundance of
  herbivorous grazers
• Aquarium fish collection may also favor algal
  growth and abundance and we should expect to see
  a change in reef areas where collecting is now
  restricted.