Kingdom Protozoa1

The Protozoans

Ciliates

Amoeboid Protozoans

Flagellated Protozoans

Kingdom Protozoa2

Protists

Defining Characteristics– All are unicellular eukaryotes– What is a prokaryote?– Many species are both heterotrophic and

autotrophic simultaneously or at different stages of the lifecycle

Eukaryote Cell

Prokaryote Cell

Kingdom Protozoa5

Adaptability

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 – Effects range from irritating - fatal

Malaria (Plasmodium spp.) worldwide epidemic

Kingdom Protozoa6

Reproduction

Asexual reproduction – Replication of chromosomes and the splitting of the parent into

two or more parts – Binary fission – Multiple fission – Budding

Protozoans are problematic in their associations as colonial forms

– Through asexual reproduction protozoans are identical and could be considered multicellular

Kingdom Protozoa7

Asexual Reproduction

Amoeba

CiliateFlagellate

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Classification

Alveolate Protozoans

Phylum Ciliophora

Phylum Dinozoa

Phylum Apicomplexa

Amoeboid Protozoans

The Rhizaria

Phylum Foraminifera

Phylum Radiozoa

Kingdom Protozoa9

Phylum Ciliophora

Defining characteristics– Body externally ciliated in at

least some lifecycle stages

Have the highest degree of subcellular specialization and are considered advanced protozoans

Paramecium feces

Kingdom Protozoa10

Cilia

Cilia – Hair-like structures by which the organism moves,

collects food and senses their surroundings

Fastest of all the protozoans

Ciliate Biology Oral groove

Cytostome

Cytoproct

Contractile vacuole

Paramecium

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Ciliate Lifestyles

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 Protozoa15

Dinoflagellates (Phylum Dinozoa)

Know for bioluminescence and highly toxic red tides – 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 Protozoa16

Phylum Apicomplexa (Sporozoa)

All members of this phylum are endoparasites– Includes Malaria (Plasmodium)– Toxoplasma gondii– Perkinsus spp.– Pneumocystis carinii

Malaria (Plasmodium)

Kingdom Protozoa18

Amoeboid Protozoans

Contains 56,000 described species 44,000 are only known as fossils

Most reproduce asexually through binary fission

Characterized by pseudopodia

Food is usually captured by phagocytosis

Body types range from free flowing to rigid with skeletal supports

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Phagocytosis

Kingdom Protozoa20

Amebas and You!

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Class Foraminifera (Rhizaria)

Defining characteristics– Individuals secrete

multi-chambered tests, generally made of calcium carbonate (CaCo3)

Foram. tests

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Foraminiferans

Extremely abundant, most are benthic and marine

Feed on diatoms and algae, very slow movers Organisms are extremely common and form

ooze– White cliffs of Dover are foraminiferan tests

Kingdom Protozoa23

Kingdom Protozoa24

Phylum Radiozoa (Rhizaria)

Defining characteristics– 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

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Radiolarians

Have shells made of silicon dioxide that can be very intricate

Feed on diatoms and other phytoplankton – Most species are planktonic

Benthic individuals move by use of pseudopodia – Can occur in large concentrations that form

ooze as well

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Zooflagellated Protozoans

Choanoflagellates

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Phytoflagellated Protozoans

Have chlorophyll and obtain energy directly from the sunlight

Some are strictly autotrophic or heterotrophic– Some are a combination of both

Both the Euglena and the dinoflagellates are examples of phytoflagellated protozoans