Phylum Apicomplexa Gregarines, Coccidians

~ 5,000 species

All parasitic

Apical complex Organelles for attaching parasite to host

cell

Hooks/suckers

Plasmodium vivax Causes malaria

Kills 1-3 million / year

Mostly in Africa

Vector = mosquito

http://www.cdc.gov/malaria/about/biology/

Malaria: important world-wide disease

• > 300-500 million infections / year• > 1 million deaths / year• Distinctive fever pattern – cyclic 48 hours

Gregarine: gut parasites of many invertebrates Best known from arthropods sporozoite

In beetle

spores

Phylum Dinoflagellata ~ 4,000 species described

Most unicellular, some are filamentous or colonial

Some planktonic, some symbiotic (w/ corals, other cnidarians)

Red tide caused by dinoflagellates Discolored area of ocean with billions of

dinoflagellates

Produce toxins, kill everything.

Two flagella: armor or not

Ceratium

Ceratium sp.

Noctiluca

Dinoflagellates Freshwater and marine Osmoregulation by pusules

Tubules that open to outside

Autotrophic and heterotrophic Switch Many photo pigments

Repro Asexual Sexual: haploid cells divide, produce

daughter cells = gametes

Forms cyst, resting stage

Phylum Rhizopoda: amebas ~ 200 species

Most free-living, some endosymbiotic, some pathogenic

Pseudopodia in all

Entamoeba histolyticaAmebic dysentery 4 nuclei - cyst found in fecal smear

Difflugia

Phylum Actinopoda ~4,240 species

Radiolarians, Heliozoans, etc. Most w/internal siliceous skeletons Planktonic and benthic Heterotrophic mostly (phagocytosis) Binary fission, budding, sex rare

Actinopoda “ray feet” = axopodia

Slender pseudopodia Actinosphaerium

Actinosphaerium

Foraminifera ~ 40,000 species All aquatic habitats Some planktonic, most benthic Tests form chalks, marble, limestone

Chalk cliffs of Dover

Phylum Diplomonadida Plasma membrane rigid from three

microtubular roots

Most phagotrophic, feed on bacteria

Asexual, most form cysts

Giardia No mitochondria, ER, or Golgi bodies Warm climates mostly In severe infections every cell in gut is

covered by a parasite. Coating of inside of intestine interferes

with absorption

Giardia lamblia

Phylum Chlorophyta “Green algae” - green chloroplasts Like plants Some colonial Some have lost photosynthesis =

heterotrophs

Volvox

Phylum Opalinida Many rows of cilia - different than in

ciliates Reproduction is longitudinal (like

flagellates), not transverse (ciliates) ~ 150 species Endosymbiotic in frog and toad gut

Phylum Opalinida Sexual repro by synamy Asexual = binary fission Opalina

Protist Phylogeny Origins ~ 2.5 bya

Evolution of eukaryotes?

Serial Endosymbiotic Theory (SET)

Serial endosymbiotic theory