Algae and Seagrasses

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Algae and Seagrasses
Algae and Seagrasses
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Vocabulary

• Seaweed
• Macrophyte
• Thallus
• Blades
• Pneumatocysts
• Holdfast
• Green algae
• Endophytes
• Brown algae
• Fucoxanthin

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Vocabulary

• 11. Red algae
• 12. Phycobilins
• 13. Coralline
• 14. Encrusting
• 15. Algin
• 16. Seagrass
• Substrate
• Rhizoid

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Photosynthetic pigments of marine plants
3 groups of photosynthetic pigments Actual
photosynthetic pigment- 1. chlorophylls Accesso
ry pigments- 2. caretenoids 3. phycoblins  
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Chlorophyta (green algae)
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Chlorophyta (green algae)

• Ulva (Sea Lettuce)
• 1.large bright green sheets
• 2.found in marine and brackish water
• 3.edible to humans

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Chlorophyta Green Algae
Codium edule
Caulerpa racemosa
Dictyosphaeria cavernosa
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Chlorophyta (green algae)

• Codium fragile - dead man's fingers

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Chlorophyta (green algae)
1. What do seaweeds provide? 2. Most
seaweeds are classified as _____________ but
others are classified as _______________. 3.
All algae has __________ inside their cells. 4.
Seaweeds are different from other plants because
they have no ______, _______, __________, or
__________.

• Chaetomorpha macro algae

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Rhodophyta Red Algae
Asparagopsis taxiformis
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Rhodophyta Red Algae
Gigartina sp. Common Name "Turkish
towel" Morphology Deep red to purple red in
color. May have bluish tint underwater. Large
blade (30-50 cm long by 10-20 cm wide) whole or
divided.
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Rhodophyta Red Algae
Porphyra sp. The popular edible nori seaweed is
from the genus Porphyra. Porphyra
described. Morphology Blades are ruffled, two
cell layers thick and usually the same in width
and length. Rhizoidal cells attach blades to the
substrate.
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Rhodophyta Red Algae

• may occur at greater depths than any other
  photosynthetic organisms
• characterized by a great deal of branching

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Rhodophyta Red Algae
Coralline algae are widespread in all of the
world's oceans, where they often cover close to
100 of rocky substrate. Many are epiphytic (grow
on other plants or marine algae), or epizoic
(grow on animals), and some are even parasitic on
other corallines. Coralline becomes strongly
calcified and contribute significantly to the
growth of coral reefs in tropical seas
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Phaeophyta Brown Algae
Hydroclathrus clathratus
Sargassum echinocarpum
Sargassum polyphyllum
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Phaeophyta Brown Algae
Like plants and many protists, brown algae
undergo a complex life cycle involving
alternation of generations. In this picture, you
can see a diploid kelp with flat photosynthetic
structures, the blades, branching from the stipe,
or stalk. The "puffy" regions attached to the
blades are receptacles, structures in which the
gametes are produced.
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Phaeophyta Brown Algae
GIANT KELP Macrocystis pyrifera

• Grows up to 2 feet a day
• Held upright by gas-filled bladders
• One of the most diverse and productive
  communities in the marine environment

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Phaeophyta (Brown algae)
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Phaeophyta (Brown algae)

• Sargassum sp.
• Morphology Main axis is cylindrical with
  leaf-like blades and air bladders. (Graham and
  Wilcox, 2000.) Can be free floating. Like M.
  pyrifera, Sargassum can protect many marine
  organisms from unfavorable coditions like high
  wave activity and predation.

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Phaeophyta (Brown algae)
1. What is drifting kelp called? 2. Why
doesnt the kelp sink once it has broken loose
from the bottom? 3. List 5 living organisms
you see near or on the drifting
kelp. a. b. c.
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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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Seagrasses
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Seagrass Parts

• The major function of the BLADES is
  photosynthesis, but they also function in
  nutrient absorption and in elimination of waste
  products.
• The SHORT SHOOT can be thought of as the "stem"
  of the plant, where the blades originate.
• RHIZOMES are subterranean organs that function in
  propagation of the clone, in anchoring the plants
  to the substrate, in translocation of materials
  throughout the clone, and are also involved in
  nutrient absorption and gas exchange. Short
  shoots and roots emanate from the rhizomes.
• ROOTS are much thinner than rhizomes and function
  primarily in nutrient absorption. They also
  contribute to anchorage of the plant and to the
  elimination of waste products.

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Seagrasses
Manatee Grass

• Manatee Grass, which has rounded leaves, occurs
  mixed with other grasses and rarely develops into
  meadows.

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Seagrasses
Turtle Grass

• 1. Turtle grass, which has thin, flattened lance
  shaped leaves, and is responsible for the
  formation of extensive meadows.

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Seagrasses
Shoal Grass

• Shoal Grass, which has thin and flat leaves, is a
  very important species in Florida. This grass is
  able to colonize areas highly disturbed with
  sediments, while the two other species are
  excluded by these adverse environmental
  conditions.

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Seagrasses

• Seagrass Bed Community
• Is formed by extensive meadows of marine
  flowering grasses. They produce an extensive
  underground network of roots and stems, called
  "Rhizomes, from which new shoots are sent up.
  They may propagate by means of fertilization or
  by re-establishment of broken pieces of the whole
  plant.

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Seagrasses

• 1. Feeding grounds -- as blades and
  associated fauna area a rich food source for
  larvae and young of both fish and invertebrates,
  the habitat presents high species diversity such
  as worms, crustaceans, mollusk, sea stars, sea
  horses, octopus, sea urchins, fishes, sea
  turtles, manatees, epiphytes, etc.
• Studies have observed at least 113 species of
  algae growing on its leaves and more than 130
  species of animals, excluding fish, living on the
  community, Some of these animals are classified
  below
• A. Filter feeders
• B. Deposit feeders
• C. Herbivores
• D. Carnivores

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Seagrasses

• 2. Nursery Grounds -- For the commercial pink
  shrimp, spiny lobster, gray snapper, sea trout,
  barracuda, grunts. The sea grass beds are
  considered the major nursery ground of the
  American Tropics.
• 3. It is here that most of the nutrients
  produced in the mangrove are utilized.
• 4. Shelter for several species of invertebrates.
• 5. Prevention of Erosion -- Blades block and
  slow water flow thus helping trap and bind fine
  sediments together.
• 6. Water Clarity -- Above process maintains water
  clarity, thus allowing the grass and
  zooxanthellae to process photosynthesis (--gt
  coral growth)
• 7. Nutrient Recycling -- Bacteria and Fungi break
  down blades and roots, making nutrients available
  to the organisms.