Colpoda

Colpoda is a genus of ciliate in the class Colpodea.

It includes the species Colpoda inflata,^[1] and at least 22 other species^[2]

Description

Colpoda are distinctly reniform (kidney shaped) and are strongly convex on one side, concave on the other. The concave side often looks like a bite was taken out of it. Although they are not as well known as the paramecium, they are often the first protozoa to appear in hay infusions , especially when the sample does not come from an existing mature source of standing water.

Habitat

Colpoda are often found in moist soil and because of their ability to readily enter protective cysts will quite frequently be found in dessicated samples of soil and vegetation^[3] as well as in temporary natural pools such as tree holes.^[4]

Reproduction

Colpoda normally divide in cysts, from which two to eight individuals emerge, four being the most common number. This produces genetically identical individuals.

However, like the Paramecium, colpoda can also reproduce by conjugation. This involves two individual joining at the oral groove and exchanging DNA, then later dividing, redistributing the DNA of the two original individuals to produce numerous genetically distinct offspring.

Species

Colpoda acuta

Colpoda aspera

Colpoda brasiliensis

Colpoda californica

Colpoda cavicola

Colpoda cucullus

Colpoda discoidea

Colpoda duodenaria

Colpoda ecaudata

Colpoda elliotti

Colpoda eurystoma

Colpoda fastigata

Colpoda formisanoi

Colpoda fragilis

Colpoda henneguyi

Colpoda inflata
Possibly one of the best known and most common species, noted for its fitful resting stage in which it jerks around in a tight circle, frustrating microscopists trying to photograph it live.^[5]

Colpoda spiralis
A very unusual species with a large overhang that gives it an almost snail like appearance. It was first found in Arizona ^[6] and has since been reported in New Mexico and Nevada, with a possible sighting in Northern California^[7].

Videos

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several dozen various sized colpoda representing at least 3 species with other ciliates 100X
Large colpoda amongst many smaller ones with other ciliates 100X
Detailed video of colpoda in resting stage 400X
Another view of colpoda in resting stage, showing relative sizes 400X
Unusual Colpoda, possibly Colpoda Spiralis 400X
Unusual Colpoda, possibly Colpoda Spiralis From when it was first spotted.