Cyphoderia laevis

 

 

Cyphoderia laevis Penard, 1902

 

Diagnosis: shell small, colorless or faintly yellowish, with a rounded fundus; pseudostome circular, relatively large compaired with Cyphoderia ampulla. In cross-section circular or more or less rounded triangular. Faintly curved neck. Nucleus vesicular, granulated, with one or two nucleoli. Filopodia very fine, active.

 

Dimensions: Penard 35-50 µm; my measurements 41-61 µm.

 

Ecology: Penard: deep lakes (Lac Léman, Loch Ness) and borders of rivers; marshes.

 

Remarks: I have seen a few specimens of this small Cyphoderia in a sample from the river Neerbeek in the village of Neer in the southern part of the Netherlands, in the marshes around Kortenhoef and in the Weser river in Germany. A large population was found in an eutrophic ditch near the village of Pingjum in the northern part of the Netherlands, together with Cyphoderia ampulla.

 

Empty shell, surface of a shell, showing small plates.
Cross-section of central area. Pseudostome with tooth-like structures.
Cell with large contractile vacuole. Fundus
Pseudostome
Specimen with long filopodium.
Cyphoderia laevis
Cyphoderia laevis, cross-section
Cyphoderia laevis, pseudostome
Cyphoderia laevis, with large vacuole
Cyphoderia laevis, 49 µm
I found this shell in a sample from a palmtree oasis in Maroc, 2014. The fundus shows some scales.
Cyphoderia laevis, 31 µm, 1979 (drawing Ferry Siemensma)