''Colpoda inflata'' (sometimes called ''Tillina inflata'' or ''Colpoda rouxi'') is a

unicellular A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and ...

organism, belonging to the genus

Colpoda Colpoda is a genus of ciliates in the class Colpodea, order Tetrahymenida, Colpodida, and family Colpodidae. Description ''Colpoda'' are distinctly reniform (kidney-shaped) and are strongly convex on one side, concave on the other. The concav ...

. Colpodeans are eucaryotic

protozoa Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...

ns, that mainly feed on bacteria (bacteriophagous), vary a lot in size and have a funnel-shaped vestibule.

Description

''Colpoda inflata'' is 30-90 μm long and is characteristically L-shaped with its oral opening, the vestibule, lying in the corner of the "L". Very well-nourished individuals can also appear reniform. ''C. inflata'' has a

macronucleus A macronucleus (formerly also meganucleus) is the larger type of nucleus in ciliates. Macronuclei are polyploid and undergo direct division without mitosis. It controls the non-reproductive cell functions, such as metabolism. During conjugation, ...

to which a

micronucleus Micronucleus is the name given to the small nucleus that forms whenever a chromosome or a fragment of a chromosome is not incorporated into one of the daughter nuclei during cell division. It usually is a sign of genotoxic events and chromosomal i ...

is attached, contractile

vacuole A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic mo ...

s, an excretory pore and several

extrusome Extrusomes are membrane-bound structures in some eukaryotes which, under certain conditions, discharge their contents outside the cell. There are a variety of different types, probably not homologous, and serving various functions. Notable extru ...

s, although populations without extrusomes have been observed. The ciliature of ''C. inflata'' is holotrichous, meaning that it is regularly distributed over the whole cell surface in slightly spiralling lines. With the help of its ciliature, ''C. inflata'' alternates between gliding rather clumsily and resting in one spot, circling jerkily. ''C. inflata'' feeds almost exclusively on bacteria, in rare cases on flagellates. Digestion takes place within its 4-8 μm-sized food vacuoles.

Habitat

The species has been found in many different terrestrial habitats like animal dunghills, sewages, meadow puddles, intestines of various reptiles and amphibians, algal coatings on tree-bark, caves and rivers.

Distribution

''C. inflata'' is distributed world-wide and has been described in the USA, Mexico and South America, Central Europe, Africa, Japan, Australia and New Zealand.

Reproduction

Conjugation Conjugation or conjugate may refer to: Linguistics * Grammatical conjugation, the modification of a verb from its basic form * Emotive conjugation or Russell's conjugation, the use of loaded language Mathematics * Complex conjugation, the chang ...

in Colpodeans has rarely been observed, which is why they are often assumed to reproduce strictly asexual. ''Colpoda inflata'' proliferates by mitosis, resulting in cells that can either form fully developed division cysts ( trophonts) or resting cysts. Resting cysts are globular and differ from division cysts by their mucous layer containing many yellow globules and their tolerance for harsh environmental conditions like low nutrient levels. The encystment process lasts about 120–160 hours.

Relevance in Science

Due to the universal distribution and its cultivability ''C. inflata'' is an ideal organism for ecological comparisons and can serve as bioindicator. Furthermore, a study has shown, that ''C. inflata'' is able to maintain great populations in highly polluted environments, which is why it could play an important role in biofilter technology.

References

{{Taxonbar, from=Q23763803 Protists described in 1884 Intramacronucleata