Download File - Bowie Aquatic Science

Algae: Kingdom Protista
 What are some characteristics we know about algae?
Algae: Kingdom Protista
 Photosynthetic, plant-like
 Vary in size: microscopic (unicellular) to macroscopic
(multicellular)
 Important primary producers in marine environments
Macroalgae Structure

Thallus: simple body
structure of algae
Typically has three parts

1.
2.
3.

Holdfast: root-like, anchors
algae to substrate
Stipe: stem-like; hold up
blades, absorbs shock of
waves,
Blades: leaf-like; site of
sexual reproduction
Gas bladders
(pneumatocyst): gas filled
floats used in flotation
Phylum Chlorophyta
 Also known as Green Algae
 Can be unicellular or multicellular
 Live in terrestrial, freshwater and marine
environments
 Contain chlorophyll a and b as the main pigment
 It is believed that plants evolved from green algae.
 Calcareous algae play an important role in the
formation of coral reefs.
Phylum Phaeophyta
 Also known as Brown Algae
 Multicellular
 Vary from olive green to dark brown
 Contains the pigment Fucoxanthin (yellow-brown) in
addition to chlorophyll a and c
 Contains the algae known as Kelp
Kelp
 Most complex and largest of all brown algae
 Areas with high density of kelp are called kelp forests
or kelp beds.
 Most are found in cold, nutrient rich, shallow waters
 Mainly found on coastlines where upwellings occur.
Sargassum
 Found in warm water
 Small, spherical air bladders to keep seaweed floating
at the surface.
 Many organisms live in sargassum and are found no
where else.
 Provides food and shelter
for baby sea turtles.
 Sargasso Sea: North Atlantic
Phylum Rhodophyta
 Also known as Red Algae
 More species than green and brown algae combined
 Contain pigments known as phycobilins (phycocyanin
and phycoerythrin) and chlorophyll a
 Coraline algae are important in coral reef formation
Importance of Algae
 Phycocolloids: gelatinous chemicals used in food
processing
-algin: stabilizer and emulsifier in dairy, processed
foods, shampoo, shaving cream, plastics, pesticides,
etc….
-carrageenan: emulsifier; gives body to dairy and
processed foods
-agar: form jellies
Kingdom Plantae
 Flowering Plants: A.K.A. Angiosperms
 Phylum Magnoliophyta
 Where do you typically find plants?
Kingdom Plantae
 Flowering Plants: A.K.A. Angiosperms
 Phylum Magnoliophyta
 Dominate the land only a few in the ocean.
 Only seagrasses are truly marine
Seagrasses
 Not grasses but members of the lily family
 Completely submerged, found in shallow subtidal
zones
 Create hiding places for other organisms
 Underground stems (rhizomes) help stabilize sandy
ocean floor
 Flower underwater and disperse pollen in thread
under water
 60 species
Marsh Grass
 Grow along the sandy beaches, never completely
submerged by water
 Halophytes: contain salt glands which help them
excrete excess salt.
 Provide habitat for crabs and mussels
 Help break down industrial pollutants that flow into
marshes
Mangroves
 Trees and shrubs adapted to live along tropical and
subtropical shores
 Important producers
 Offer protection for young organisms
 Over 80 different species
Mangrove Adaptations
Coping with salt:
 filtering out as much as 90 percent of the salt found in
seawater as it enters their roots.
 Some species excrete salt through glands in their
leaves.
 concentrate salt in older leaves or bark, when the
leaves drop or the bark sheds, the stored salt goes with
them.
Hoard fresh water:
 Like desert plants, mangroves store fresh water in
thick succulent leaves.
 A waxy coating on the leaves of some mangrove
species seals in water and minimizes evaporation.
 Small hairs on the leaves of other species deflect wind
and sunlight, which reduces water loss through the
tiny openings where gases enter and exit during
photosynthesis..
Breathe in a variety of ways:
 Some mangroves grow pencil-like roots that stick up
out of the dense, wet ground like snorkels. These
breathing tubes, called pneumatophores, allow
mangroves to cope with daily
flooding by the tides.
Pneumatophores take
in oxygen from the air
unless they're clogged
or submerged for too long.