world of amoeboid organisms



Before a new shell is made, the amoeba collects building material in its environment. In this case Difflugia lobostoma uses small mineral grains, in other words: minute sand grains.
Amoebae can also use diatom shells or fragments, and mix it with mineral grains. Some amoeba secrete their own building material, called idiosomes, like granules (Arcella), squared plates (e.g. Quadrulella) or circular ones (e.g. Trinema, Cyphoderia). Other species strip the plates from the shells of their prey. In Nebela-species one can often see where the plates are derived from.
When the new shell is build, the amoeba uses its own cytoplasm as a matrix for the new shell. It secretes an organic cement and the mineral grains are arranged all over the matrix, often in a very regular and symmetric way. The organic cement hardens and holds the embedded material together.
The formation of a new shell can be completed within half an hour! See here for another division.

The new shell (right) is completed; it has a lighter color. In this case the amoeba moved into the new shell…
…and the old one was abandoned. Usually the cytoplasm divides and one of the cells moves into the new shell.
Recent posts

Zivkovicia compressoidea

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Zivkovicia flexa

Z. flexa, from Cash and Hopkinson, 1909 Zivkovicia flexa  (Cash and Hopkinson, 1909) Ogden, 1983 Basionym: Pontigulasia compressa var. flexa  Cash and Hopkinson, 1909 Diagnosis:

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Lagenodifflugia epiouxi

L. epiouxi, after Chardez, 1984 3 Lagenodifflugia epiouxi (Chardez, 1983) new comb. Basionym: Pontigulasia epiouxi Chardez, 1983 Diagnosis: Shell elongate, circular in cross-section or very

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Centropyxis lapponica

Centropyxis lapponica, after Grospietsch, 1954 Centropyxis lapponica  Grospietsch, 1954 Diagnosis: Shell nearly circular in circumference, without spines. Aperture clear square with rounded corners. Shell viewed

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Chaos spec. 6

Chaos spec., Crailoo, 2021 Chaos spec. This specimen was found in a samples from Crailoo, Netherlands. It was remarkable because of the absence of crystals.

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Bullinularia maxima

Bullinularia maxima – from Bobrov and Mazei, 2020 Bullinularia maxima Bobrov et Mazei, 2020 Diagnosis: Shell brown, opaque, elliptical in ventral view; ventral surface is

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Bullinularia macroporum

Bullinularia macroporum – from Bobrov and Mazei, 2020 Bullinularia macroporum Bobrov et Mazei, 2020 Diagnosis: Shell yellow-brownish, transparent, circular in ventral view; ventral surface is

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Nebela golemanskyi

N. golemanskyi, after Todorov, 2010 Nebela golemanskyi Todorov, 2010 Diagnosis: Shell large, colourless and pyriform, with a distinct short neck about one fourth of the

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Nebela nebeloides

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