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Chaos glabrum (original isolate).

UB1, DIC/Bright field.
Locomotive forms, nucleus and uroidal structures.

Photo: A.Smirnov

Chaos glabrum (original isolate).

1: nucleus, 2: two types of mitochondria; 3: nuclear lamina; 4: amorphous cell coat

TEM: A.Smirnov

Chaos glabrum Smirnov & Goodkov, 1997 (original isolate)

  • Lentgh in locomotion: when polytactic - about 500 mkm, orthotactic locomotive form 420-980 mkm (average 816 mkm). Majority of amoebae orthotactic in locomotion (monopodial with distinct lateral wrinkles), few are polytactic (polypodial). Crystals are truncate bipyramids, spindles and cubes. Floating form of radial type; several thick pseudopodia of unequal lenght radiate from irregular central mass of the granuloplasm.

  • 6-30 discoid, biconvex nuclei of granular type, about 20 mkm in diameter.

  • Surface coat amorphous, 50-60 nm in thickness, consists of two distinct layers; mitochondrial heteromorphism is known; honeycomb-like nuclear lamina (Smirnov & Goodkov, 1997).

  • This species resembles Chaos nobile very much. The differences are the floating form (Chaos nobile has a very specific floating form (see Page, 1988)) and ultrastructure of the cell coat. TEM of the cell coat is obligate for identification, keep in mind that filaments in proteus-like amoebae may coagulate under the EM fixation.

  • There is now available cultures of this species. All data were obtained from the original isolate. Type slides (iron haemotoxylin) are deposited with the museum of preparations of the laboratory of Invertebrate Zoology, Biological Research Inst. of St.Petersburg State University, under the numbers #1994:704, #1994:705-706. Known only from the original habitat.

  • Freshwater, North-Western Russia, Valamo island.
    Cultivation: was maintained for some time in PJ + wheat (rise) grain, in presence of small ciliates and flagellates.

  • Basic references for identification:
    • Smirnov A.V. and Goodkov A.V. 1997. Description of a large, multinucleate lobose amoeba Chaos glabrum n.sp. (Lobosea, Amoebidae), with notes on the diagnosis of the genus Chaos. Acta Protozool. 36: 227-233.

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