Unicellular Marine Organisms
Unicellular Marine Organisms
Classifying Marine Organisms
Plankton: “Drifters” move with ocean
currents
Nekton: “Swimmers” Free to move
through out the water column
Benthos: “Bottom Dwellers” live on the
substrate may be motile or sessile
Unicellular Marine Organisms
Unicellular Marine Organisms
5 Kingdom Classification system
Monera:
Monera:
Unicellular
Lack nucleus in cells
Archebacteria and Eubacteria
Cyanobacteria
Unicellular Marine Organisms
5 Kingdom Classification system
Protista
Single Celled, Have nucleus in
cells
Algae: Plant- like protists
Slime molds: Fungus- like
protists
Protozoans:
Protozoans: Animal- like protists
Unicellular Marine Organisms
5 Kingdom Classification system
Protista
Ameobas
Posses Pseudopods“false feet”
These are used to engulf food
particles
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Unicellular Marine Organisms
Unicellular Marine Organisms
•Radiolarians
–Amoeba with SiO2 (Glass) Tests
(shells)
–Feed on phytoplankton
–Extend Psuedopods through holes in
test
Unicellular Marine Organisms
Unicellular Marine Organisms
•Foramaniferans “forams”
forams”
–Amoeba with CaCO2 test
–Also use pseudopods to capture prey
–Tests of “forams
“forams”” and radiolarians sink
to the bottom and form sediments
•“Foram”
Foram” tests form limestones such as
chalk
•Radiolarian tests form silicate sand
Unicellular Marine Organisms
Unicellular Marine Organisms
•Unicellular Algae
•Diatoms
–Diatoms are abundant worldwide
–They are autotrophic
–Typically yellow in color
–They posses tests made of silicate similar to those of
radiolarians
–Diatoms typically have tests made from two unequal
halves that fit together like a box and lid.
–Sediments made from diatom tests are called
Diatomaceous Earth and are important industrial
products for filtration and abrasion
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Unicellular Marine Organisms
Unicellular Marine Organisms
•Unicellular Algae
•Coccolithophores
–Tiny marine algae with calcium carbonate tests
–Tests are formed from overlapping plates called
coccoliths
–Coccolithofores form the basis for many marine food
chains
Unicellular Marine Organisms
Unicellular Marine Organisms
•Unicellular Algae
•Dinoflagellates
•Important marine phytoplankton
•Both autotrophic AND heterotrophic
•Posses a test formed of cellulose
–similar to the cell wall of a plant cell
•Have two flagella
–one that extends out from the cell
–one that is contained in a groove in the test
•Some species are responsible for red tides
•These species are toxic to fish and humans
•Zooxanthellae are commonly symbiotic with animals such
as worms, mollusks and cnidarians
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