GC: n

S: WHO – (last access: 27 November 2014); NCBI – (last access: 27 November 2014).

N: 1. 1828, from Modern Latin protozoa, coined 1818 by German zoologist Georg August Goldfuss (1782-1848) from Greek protos “first” + zoia, plural of zoion “animal”. Originally including sponges and corals; current sense is from 1845.
2. Organism, usually single-celled and heterotrophic (using organic carbon as a source of energy), belonging to any of the major lineages of protistsand, like most protists, typically microscopic. All protozoans are eukaryotes and therefore possess a “true,” or membrane-bound, nucleus. They also are nonfilamentous and are confined to moist or aquatic habitats, being ubiquitous in such environments worldwide, from the South Pole to the North Pole. Many are symbionts of other organisms, and some species are parasites.
3. Anton van Leeuwenhoek was the first person to see protozoa, using microscopes he constructed with simple lenses. Between 1674 and 1716, he described, in addition to free-living protozoa, several parasitic species from animals, and Giardia lamblia from his own stools.
4. There are four main types of protozoa: ciliates, flagellates, amoebas and freshwater radiolaran.
5. Most protozoans are too small to be seen with the naked eye – most are around 0.01-0.05 mm, although forms up to 0.5 mm are still fairly common – but can easily be found under a microscope.
6. More than 50,000 species have been described, most of which are free-living organisms; protozoa are found in almost every possible habitat. The fossil record in the form of shells in sedimentary rocks shows that protozoa were present in the Pre-cambrian era.

S: OED – (last access: 25 November 2014). 2. EncBrit – (last access: 25 November 2014). 3. NCBI – (last access: 25 November 2014). 4. EOL – (last access: 25 November 2014). 5. SD – (last access: 25 November 2014). 6. NCBI – (last access: 25 November 2014).

SYN: protozoan, protozoon.

S: TERMIUM PLUS (last access: 27 November 2014)

CR: malaria, malaria parasite, parasite, protozoosis.