Animal-Like Protists
 Heterotrophic
 Classified by means of locomotion: flagella, cilia,
pseudopods, or none (sessile)
 Many free living, some parasites of humans and
animals
Paramecium (many species) is free living
Animal-Like Protists
Phylum Protozoa
 Locomotion by pseudopodia  cytoplasmic
streaming/cyclosis  amoeboid movement
 Prey on bacteria, ingest food particles in water using
pseudopodia  vesicle, intracellular digestion
 Subphylum Sarcodina - amoebas: freshwater,
marine or soil; some have a test/shell around cell
membrane
 Subphylum Mycetozoa – some have glassy shells
(radiolarians)
Testate Amoebas
Simple tests (or shells) are made by either secretion or by the
agglutination of foreign material or a combination of both.
Environmental changes can be determined by analyzing the
composition of tests, including fossil tests, which may indicate
past climatic conditions.
Radiolarian (marine amoeba) shells
Animal-Like Protists
Phylum Ciliophora
 Locomotion by cilia
 Asexual reproduction – binary fission
 Most elaborate organelles of any protist:
 Macronucleus that controls cell functions
 Micronucleus exchanged through conjugation (sexual
reproduction)
 pellicle (elastic layer of protein) surrouding cell membrane
 Food acquisition: oral groove  mouth pore  gullet 
food vacuoles
 Excretion: anal pore  contractile vacuole
Animal-Like Protists
Phylum Sarcomastigophora
Trypanosomes in human blood
Tsetse fly (vector)
 One or more flagella
 Subphylum Mastigophora – many free living, some parasites
 genus Trypanosoma
 Infect blood in many vertebrates
 Transmitted by insect vectors
Ex.: African sleeping sickness, caused by two species of
trypanosomes, transmitted by tse-tse fly  fever,
lethargy, eventual coma, death;
Giardia – found in fresh water  gastrointestinal disease
Giardia lamblia causes
giardiasis, an intestinal
infection
Found in freshwater –
streams & rivers
Cysts carried in animal
feces
Animal-Like Protists
Phylum Apicomplexa
(former sporozoans)
Plasmodium faciparum
 no adaptations for locomotion  all animal parasites
 Apical complex = organelles specialized for entry into host
cells/tissues
 Complex life cyles with sexual and asexual stages, often
more than one host
 Plasmodium – mosquito vector  malaria
 Toxoplasma gondii – affects developing fetuses,
newborns
 Cryptosporidium – found in water, animal feces 
gastrointestinal disease
Anopheles mosquito vector
Malaria life cycle
on UTube
Malaria
350–500 million
cases / year, killing
one to three million
people
Fungus-Like Protists
Slime Molds & Water Molds
 Uni- or multi-cellular, all heterotrophic
 Saprophytic, some parasitic
Fungus-Like Protists
Phylum Myxomycota –
Plasmodial Slime Molds
 Feeding stage = Plasmodium,
a multinucleated (2n) mass
of cytoplasm
 Amoeboid movement by
cytoplasmic streaming
 phagocytosis of decaying
matter
 Reproductive state = Fruiting
bodies produce haploid
spores by meiosis
 Spores produce haploid
(n) reproductive cells that
fuse (2n)
 mitosis w/o cytokinesis 
multinucleated
plasmodium (unicellular)
Physarum life cycle
Fungus-Like Protists
Phylum Dictyostelida –
Cellular Slime Molds
 Individual haploid cells live independently
 Scarcity of food triggers release of chemical that
attract others
 Many cells gather to form a multi-cellular
pseudoplasmodium – (each cell retains its
membrane)  develops fruiting bodies  haploid
spores  new independent haploid cells
How do cellular slime molds differ from plasmodial slime molds?
Fungus-Like Protists
Phylum Oomycota – Water Molds
 Asexual reproduction -- flagellated zoospores 
threadlike cells
 Sexual reproduction – egg and sperm produced 
fertilization tubes  zygote  threadlike cells
Water mold
on dead
mayfly larva
Fungus-Like Protists
Phylum Chytridiomycota –
Water Molds
Healthy Tasmanian frog
 Most unicellular, parasitic
 Make flagellated gametes
and zoospores
 Chitin in cell walls,
filamentous cells,
enzymes and
biochemistry similar to
fungi 
 some classify them in
kingdom Fungi
 may be a transitional
form between protists
and fungi
Infected frog
Chytrid (microscopic)