### microprotozoan:

Radiolarian
* Most radiolarians are planktonic , and get around by coasting along ocean currents.
* are abundant and well preserved in almost all samples examined
  - also an important component of the phytoplankton , especially in warmer waters
  - beautiful, microscopic, single-celled animals that built skeletons out of silica
  - generally rare and show signs of dissolution in almost all samples
  - of large size as protozoans go
  - one-celled animals with beautiful, complicated skeletons
  - planktonic amoebic protistans
  - tiny protozoans that live exclusively in the ocean
* have elaborate skeletons made mostly of silica.
* have shells made of silica instead of calcium carbonate
  - of silica, which produce siliceous oozes in the equatorial regions
  - such a good fossil record because their silicon skeletons preserve so well
* inhabit open water throughout the oceans.
* live in large quantities as part of the ocean's plankton.

Sporozoan
* All sporozoans are parasites.
* Many sporozoans causes serious diseases in humans.
* Some sporozoans have cilia.
* are spore-forming parasites of animals.
* cause diseases such as malaria and cryptosporidiosis.
* have a com- plex life cycle with sexual and asexual stages
  - no physical form of movement
* includes cell membranes
  - cells
  - corpi
  - cytoplasm
  - lips
  - mouths
  - nuclei
  - plasma membranes
  - sections
  - vacuoles

### microprotozoan | sporozoan:

Malaria parasite
* Most malaria parasites cause infection.
* Most malaria parasites have life stages
  - origins
* Most malaria parasites infect mammals
  - other mammals
* Most malaria parasites show different phases
  - undergo development
* Some malaria parasites are resistant to current treatments.

### microprotozoan | sporozoan:

Merozoite
* Some merozoites behave as gametes
  - can divide asexually to produce haploid cells, called gametocytes
  - develop into macrogametocyte and microgametocyte
* are elongate, crescent-shaped, and contain a single, prominent, basophilic nucleus.
* burst from the host cell and infect more host cells.
* enter either new hepatic cells or RBCs.
* entering muscle cells round up to form metrocytes and initiate sarcocyst formation.
* infect rbc, divide rapidly, lyse the infected rbc and release many more merozoites
  - red blood cells
* invade red blood cells and continue to reproduce asexually
  - the blood stream and infect the erythrocytes
* mature and burst the cell, releasing metabolic wastes.
* penetrate new cells and undergo merogony to form additional meronts.

### microprotozoan | sporozoan:

Sporozoite
* are elongate, club shaped, and contain two prominent refractile bodies
  - each with two refractile globules
  - formed in the sporocyst by cell division
  - infectious cells of organism and are able to penetrate host cells and tissues
  - small cells that lie within the thickwalled resistant spore
  - vermiform, lying parallel within the sporocyst
* develop in the sporocysts, their number depending on the species
  - within the oocyst and migrate in haemolymph to invade the salivary glands
* enter host cells by constructing a unique vacuolar structure
  - the blood during tick feeding
* excyst and invade intestinal cells, become tachyzoites and multiply
  - from I. felis oocysts in the small intestine
  - through breaks in the cyst wall and then are termed trophozoites
* go to the liver , where they make many more sporozoites.
* infect liver cells and mature into schizonts , which rupture and release merozoites.
* penetrate epithelial cells, especially along the ileum.
+ Malaria, Malaria parasite life cycle: Diseases spread by insects :: Parasites :: Apicomplexa
  * When 'Plasmodium' enters the blood, they are then called 'sporozoites'. Sporozoites go to the liver, where they make many more sporozoites. Then they change into a different form of 'Plasmodium'. This form is the 'merozoite'. The merozoites go into the red blood cells, then they make many more merozoites.