First in our survey of life in ocean
 Devoted to marine microorganisms

› Most abundant
› Live everywhere in the ocean
 From the deepest trenches
 To the highest tide pools

Members of the domains Bacteria and
Archaea are prokaryotic
› Cells lack a nucleus and other membrane-
bound organelles

Differences:
› Chemistry of cell walls and plasma
membranes
› Cellular machinery that manufactures
proteins

Symbiotic bacteria
› Digests wood ingested by shipworms
(Teredo),
Symbiotic bacteria
› Shipworms
 Are bivalve molluscs, not worms
 Lack cellulase – enzyme that breaks down
cellulose, main component of wood
Symbiotic bacteria
 Bioluminescence
› To communicate with other members of their
species
› Lure prey
› Blend with the light that filters from the
surface
Symbiotic bacteria
 Bioluminescence

Macropinna microstoma: A deep-sea
fish with a transparent head and tubular
eyes
http://www.youtube.com/watch?v=RM9o4VnfHJU&edufilter=DQBPVNZ5nlfNZmzO0OgIrQ
Symbiotic bacteria
 Chemosynthetic
 bacteria is symbiotic with mussels, clams,
and tube worms that live around deep-sea
hydrothermal vents
› Manufacture organic matter from CO2 and
hydrogen sulfide (H2S) from the vents.
› Symbiotic bacteria live in a special organ of
tube worm Riftia
Symbiotic bacteria
 Chemosynthetic bacteria is symbiotic
with mussels, clams, and tube worms that
live around deep-sea hydrothermal
vents
Symbiotic bacteria
http://www.youtube.com/watch?v=YGv2QxmaRI0&edufilter=DQBPVNZ5nlfNZmzO0OgIrQ
Symbiotic bacteria
 Japanese pufferfish
› Delicacy in Japan; “fugu”
› Store toxins
 Toxins produced by symbiotic bacteria not the
fish
 Fish immune to toxins
 Toxins deadly to predators (or humans) who
eat the fish.
http://video.nationalgeographic.com/video/animals/fish-animals/spiny-rayed-fish/pufferfish/
Autotrophic bacteria
Make their own food
Photosynthetic
 Chemosynthetic

Autotrophic bacteria
Make their own food

Photosynthetic
› Contain chlorophyll or other photosynthetic
pigments to capture sunlight to make food
(like seaweeds and plants)
Cyanobacteria
 Once known as blue-green algae
 Photosynthetic
› Pigments
 Chlorophyll – green
 Phycocyanin – bluish
 Phycoerythrin – reddish

Carry out nitrogen fixation
› Converting gaseous nitrogen (N2) into other
nitrogen compounds that can be used by other
primary producers
Stromatolites, calcareous mounds
deposited by cyanobacteria are
frequently found as fossils. These,
however, are living stromatolites
growing in shallow water in the
Exuma Cays, Bahama Islands.
Animal-like
Plant-like
Diatoms
 Dinoflagellates

Diatoms
 Unicellular
 Live as plankton
 Cell walls made of silica (SiO2), glass-like
material
› Used in products: filters for swimming pools,
temperature and sound insulators, abrasives
in toothpaste

Primary producers in open water
Dinoflagellates
 Planktonic, unicellular organisms.
 Two flagella
› One wrapped around a groove along the
middle of the cell
› One trailing free
Have a cell wall
that is armored
 Mostly autotrophs,
some heterotrophic
 Some bioluminescent

Animal-like protists
 Foraminiferans
 Radiolarians
 Ciliates
Foraminiferans
 Shell made of calcium carbonate
 Most benthic
 Some planktonic
› Shells important components of marine
sediment

Pseudopodia
(extensions of
cytoplasm) for movement
http://www.youtube.com/watch?v=f5cetm-fj3Y&edufilter=DQBPVNZ5nlfNZmzO0OgIrQ
Radiolarians
 Shells made primarily of silica (glass)
 Sediments cover large area of ocean
floor.
Ciliates
 Have many hair-like cilia used in
locomotion and feeding.
 Most familiar – paramecium
http://www.youtube.com/watch?v=lGpudS9IjHg&edufilter=DQBPVNZ5nlfNZmzO0OgIrQ
General Structure: seaweed vs land plant
General Structure: seaweed vs land plant
 Thallus- name for entire structure
 Blades – photosynthetic region of thallus;
leaf-like, but lacks veins
 Pneumatocysts – gas filled bladders;
keeps blades close to surface
 Stipe – stem-like structure from which
blade orginates
 Holdfast – anchors thallus to bottom
General Structure: seaweed vs land plant
Types of Seaweed
 Green
algae/Chlorophyta
› Largely unicellular
› Non-marine;
freshwater habitat
› Bright-green due to
large amounts of
chlorophyll; also
contains
carotenoid
pigments (yellowbrown)
Types of Seaweed
 Green algae
 Brown algae
 Red algae
Types of Seaweed
 Brown algae
 Includes largest and
most structurally
complex seaweeds
› Chlorophyll found
together with
carotenoids
Types of Seaweed
 Red algae
› Largest group
› Chlorophyll masked by red pigment; also
contains carotenoids
Economic Importance
FOOD
Have you had algae for
dinner?
Algin
Carrageenan
Beta carotene
Brownie mix
Cheese (yellow and orange)
Chocolate milk
Coffee creamer
Cottage cheese
Egg substitute
Evaporated milk
Frozen foods and desserts
Frozen yogurt
Ice cream
Infant Formula
Margarine
Mayonnaise
Multiple vitamins
Pet food
Pudding (cooked)
Relishes
Salad dressing
Sauces and gravies
Sour cream
Toothpaste
Whipped cream
Yogurt
If you have used any of
those products,
You have likely eaten
ALGAE
Almost all flowering plants or angiosperms
live on land EXCEPT three groups:
Seagrasses
 Salt-Marsh plants
 Mangroves

Seagrasses
 Truly marine
 Rarely exposed to air
Salt-marsh plants
 Land plant
 Salt tolerant
 Grow soft-bottom
coastal regions
Mangroves
 Land plant
 Salt tolerant
 Grow along shore
Reproduction
 Involves a dominant sporophyte
›
Features an elaborate reproductive organ,
the flower.