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

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

Read More »

Nebela nebeloides

N. nebeloides, after Gauthier-Lièvre and Thomas, 1958 Nebela nebeloides (Gauthier-Lièvre and Thomas, 1958) Todorov et al., 2010 Basionym: Difflugia nebeloides Gauthier-Lièvre and Thomas, 1958 Diagnosis:

Read More »

Difflugia biwae

D. biwae, after Yang and Shen, 2005 Difflugia biwae Kawamura, 1918 Diagnosis: Shell in lateral view fusiform in outline with a straight neck, a conspicuous

Read More »

Difflugia mulanensis

D. mulanensis, after Yang et al., 2015 Difflugia mulanensis Yang, Meisterfeld, Zhang and Shen, 2015 Diagnosis: Shell elongate ovoid like a vase, with a distinct

Read More »

Euglypha bryophila

Euglypha bryophila, after Brown, 1911 (L), from Ecuador (R) Euglypha bryophila  Brown, 1911 Diagnosis: (Original description) The test is very regular in form and subject

Read More »


(A) A Scenedesmus cell (arrow) is engulfed by a trophozoite. (B) Several Scenedesmus cells adhere to the surface of a plasmodium that has numerous vacuoles

Read More »