The Protozoans
Ciliates
Amoeboid Protozoans
Flagellated Protozoans
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Kingdom Protozoa
Protists
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Defining Characteristics
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All are unicellular eukaryotes
What is a prokaryote?
Many species are both heterotrophic and
autotrophic simultaneously or at different stages of
the lifecycle
Kingdom Protozoa
Eukaryote Cell
Prokaryote Cell
Adaptability
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Protozoans are ecologically important primary
producers, consumers and as vital links in the
food chain
Humans are greatly effected by parasitic
protozoans either directly or indirectly
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Effects range from irritating - fatal
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Malaria (Plasmodium spp.) worldwide epidemic
Kingdom Protozoa
Reproduction
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Asexual reproduction
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Replication of chromosomes and the splitting of the parent into
two or more parts
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Binary fission
Multiple fission
Budding
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Protozoans are problematic in their associations as
colonial forms
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Through asexual reproduction protozoans are identical and
could be considered multicellular
Kingdom Protozoa
Asexual Reproduction
Amoeba
Flagellate
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Ciliate
Kingdom Protozoa
Classification
Alveolate Protozoans
Phylum Ciliophora
Phylum Dinozoa
Phylum Apicomplexa
Amoeboid Protozoans
The Rhizaria
Phylum Foraminifera
Phylum Radiozoa
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Kingdom Protozoa
Phylum Ciliophora
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Defining characteristics
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Body externally ciliated in at
least some lifecycle stages
Have the highest degree of
subcellular specialization
and are considered
advanced protozoans
Paramecium feces
Kingdom Protozoa
Cilia
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Cilia
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Hair-like structures by which the organism moves,
collects food and senses their surroundings
Fastest of all the protozoans
Kingdom Protozoa
Ciliate Biology
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Oral groove
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Cytostome
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Cytoproct
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Contractile vacuole
Paramecium
Ciliate Lifestyles
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65% of all ciliate
species are free-living
and mobile
Some ciliates form
colonial aggregations
and have sessile
habits
Other ciliates have
symbiotic relationships
in invertebrates and
vertebrates
Vorticella
Kingdom Protozoa
Dinoflagellates (Phylum Dinozoa)
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Know for bioluminescence and highly toxic red
tides
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Dense aggregations produce saxitoxin killing fish and
crustaceans
Also contaminates shellfish causing diarrheic
shellfish poisoning
Some benthic dinoflagellates produce a
neurotoxin that accumulates in tropical fish called
Ciguatera
Kingdom Protozoa
Phylum Apicomplexa (Sporozoa)
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All members of this phylum are endoparasites
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Includes Malaria (Plasmodium)
Toxoplasma gondii
Perkinsus spp.
Pneumocystis carinii
Kingdom Protozoa
Malaria (Plasmodium)
Amoeboid Protozoans
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Contains 56,000
described species
44,000 are only
known as fossils
Most reproduce
asexually through
binary fission
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Characterized by
pseudopodia
Food is usually
captured by
phagocytosis
Body types range from
free flowing to rigid with
skeletal supports
Kingdom Protozoa
Phagocytosis
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Kingdom Protozoa
Amebas and You!
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Kingdom Protozoa
Class Foraminifera (Rhizaria)
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Defining
characteristics
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Individuals secrete
multi-chambered
tests, generally
made of calcium
carbonate (CaCo3)
Foram. tests
Kingdom Protozoa
Foraminiferans
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Extremely abundant, most are benthic and
marine
Feed on diatoms and algae, very slow movers
Organisms are extremely common and form
ooze
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White cliffs of Dover are foraminiferan tests
Kingdom Protozoa
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Kingdom Protozoa
Phylum Radiozoa (Rhizaria)
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Defining characteristics
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Body is divided into distinct
zones separated by a
perforated membrane or
capsule
Have pseudopodia
supported with thin
microtubules that give a
spiny rayed appearance
Kingdom Protozoa
Radiolarians
Have shells made of silicon dioxide that
can be very intricate
 Feed on diatoms and other phytoplankton
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Benthic individuals move by use of
pseudopodia
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Most species are planktonic
Can occur in large concentrations that form
ooze as well
Kingdom Protozoa
Zooflagellated Protozoans
Choanoflagellates
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Kingdom Protozoa
Phytoflagellated Protozoans
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Have chlorophyll and obtain energy directly
from the sunlight
Some are strictly autotrophic or heterotrophic
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Some are a combination of both
Both the Euglena and the dinoflagellates are
examples of phytoflagellated protozoans
Kingdom Protozoa