Difflugia binucleata
Difflugia binucleata
D. binucleata, 132 and 144 µm

 
Difflugia binucleata Penard, 1902

Diagnostics: Test ovoid with a distinct neck, thus resembling a vase. Test mainly composed of fragments of diatom shells, embedded in an organic matrix. Test often with adhering debris and therefore hard to detect between sediments. Always two vesicular nuclei present. Color yellow till brown.

Dimensions: Penard length 100 – 135 µm; my measurements 130 – 216 µm, mean 152 µm.

Ecology: mesotrophic watertype; debris in Sphagnum pools and between waterplants in ditches with Sphagnum contact. A rich population is present in the pond of Crailoo, the Netherlands.

Remarks: In 1904 Penard described this remarkable species (see his drawing below). As main characteristic he mentions the presence of two nuclei, hence the name. Another remarkable fact is that the test of this species is covered with a loose layer of debris, mainly around the neck and aperture. Therefore the shell might be hard to detect for non-specialists. The test has a distinct collar with a distinct neck. The test is mainly composed of fragments of diatom tests.

Difflugia binucleata nucleus
Difflugia binucleata nucleus
D. binucleata, nucleus, in phase contrast and normal illumination
D. binucleata, with obliquely cut pseudostome and brown cement between the xenosomes, stacked image
D. binucleata, division. The newly built test is surrounded by loosely attached debris. The dark test is the same as in the photomicrograph above it.
Difflugia binucleata
Difflugia binucleata
Difflugia binucleata, 130 and 132 µm
Difflugia binucleata
Original drawings of Penard (1902) in Faune Rhizopodique du Bassin du Leman.
Difflugia binucleata
Difflugia binucleata
Difflugia binucleata, 135 µm
Difflugia binucleata
Difflugia binucleata
Difflugia binucleata, 162 µm, typical habitus.
Difflugia binucleata
Difflugia binucleata
Difflugia binucleata, 130 µm

 

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