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Microcometes paludosa

Genus Microcometes Cienkowsky, 1876

Diagnosis: Shell hyaline, usually dark brown, small, with one side fastened to the substrate; outline polygonal, irregular; shell with three to five apertures, with or without short necks. Pseudopodia very thin, granular, branching. Usually with two short cilia. Nucleus globular with a central nucleolus. Three to six contractile vacuoles.

Type species: Microcometes paludosa Cienkowski, 1876

Dimensions: De Saedeleer (1934): shell 6.8-17 µm. My measurements: 9.0-11.2 µm.

Ecology: freshwater; bacterivorous.

Remarks: The two cilia are easily overlooked and even the filopodia are hard to detect. Because of these cilia, this genus has been moved to the heterotrophic ciliates.

De Saedeleer (1934) describes two species, Microcometes paludosa and M. aculeata, with short spines. The latter has originally been described by Lauterborn (1908) as M. paludosa var. aculeata.

Microcometes paludosa is not rare, but usually not easy to discover in fresh preparations. Best is to keep preparations in moist chambers and to scan them regularly. Specimens mostly attach to the cover glass and are easily visible because of the dark brown color.

Click here for the original description of Cienkowski.

Microcometes paludosa - Ferry Siemensma
Microcometes paludosa
Microcometes paludosa - Ferry Siemensma
Microcometes paludosa with three apertures
bar = 10 µm
Microcometes paludosa
Microcometes paludosa – Photomicrograph: Yana Egli
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