world of amoeboid organisms

Difflugia sp.
D. yorkui, 273-307 µm (Naardermeer)

Difflugia yorkui Nicholls, 2007

Diagnosis: Shell large, elongated oblong, usually with a distinct neck and covered with large and irregularly shaped siliceous particles except in the anterior region where particles are very small; test roughly circular (not compressed) in transverse cross-section, tapering towards both anterior and posterior ends from its widest point at about the middle of the test. Aperture relatively small and circular,  . Organic basal material of the test (cement) organized in an open-meshed pattern of pores 0.3-0.8 µm in diameter separated by ribs 0.2-0.4 µm in width. With zoochlorellae. Nucleus ovular, densely filled with numerous small spherical nucleoli.

Dimensions: Nicholls (2007): Length 305-370 µm; width 140-162 µm; aperture 50-63 µm in diameter (n=12); my measurements: Length 222-460 µm (mean 365 µm); width 118-200 µm; aperture 56-101 µm (n=39).

Ecology: Freshwater; Canada, Netherlands (Naardermeer and several other locations).

Remarks: The identity of the Dutch shells was confirmed by Nicholls (pers. comm., 2021)

Difflugia yorkui
D. yorkui, reworked after Nicholls, 2007
Difflugia sp.
D. yorkui, 292 µm – stacked image, (Naardermeer)
D. yorkui
D. yorkui, 326 µm – 428 µm, (Naardermeer), all from the same sample.
Difflugia sp.
D. yorkui, nucleus in squeezed cell. Notice the zoochlorellae and the ingested diatoms.
Difflugia sp.
D. yorkui, shell ratio Length / Width (n=39)
Recent posts

Zivkovicia compressoidea

Z. compressoidea, a-b after Chardez, 1958; c after Jung, 1942 Zivkovicia compressoidea  (Jung, 1942) new.comb. Basionym: Pontigulasia compressoidea Jung, 1942 Diagnosis: Shell ovoid and compressed,

Read More »

Zivkovicia flexa

Zivkovicia flexa, from Cash and Hopkinson, 1909 Zivkovicia flexa  (Cash and Hopkinson, 1909) Ogden, 1983 Basionym: Pontigulasia compressa var. flexa  Cash and Hopkinson, 1909 Diagnosis:

Read More »

Lagenodifflugia epiouxi

L. epiouxi, after Chardez, 1984 3 Lagenodifflugia epiouxi (Chardez, 1983) new comb. Basionym: Pontigulasia epiouxi Chardez, 1983 Diagnosis: Shell elongate, circular in cross-section or very

Read More »

Centropyxis lapponica

Centropyxis lapponica, after Grospietsch, 1954 Centropyxis lapponica  Grospietsch, 1954 Diagnosis: Shell nearly circular in circumference, without spines. Aperture clear square with rounded corners. Shell viewed

Read More »

Chaos spec. 6

Chaos spec., Crailoo, 2021 Chaos spec. This specimen was found in a samples from Crailoo, Netherlands. It was remarkable because of the absence of crystals.

Read More »