world of amoeboid organisms

Menu
Difflugia viscidula
 
D. viscidula 273-307 µm

 

Difflugia viscidula Penard, 1902 pars

Diagnosis: shell elongated oblong, usually with a distinct neck, composed of much smaller particles than the rest of the shell; with zoochlorellae.

Dimensions: Penard (1902): 180-260 µm; my measurements: length 222-460 µm (mean 365 µm); width 118-200 µm; aperture 56-101 µm.

Ecology: fresh water; Switzerland; the Netherlands (Naardermeer and several other locations).

Remarks: Penard described this species in 1902 as D. viscidula, but in 1905 he wrote that he had made a mistake by which he thought that D. lemani was a much smaller species. He noticed erroneously 31-80 µm, instead of 180-310 µm, as given by Blanc (1892). However, he gives three different drawings (see below). No 1 and 2 seem to be the same as described by Blanc, but no 3 is different by having a clear neck. I have found both types and I think that there are at least two different species. The oblong (acorn) type and the elongated one with the neck.

Difflugia viscidula
Drawing: Penard (1902) in Faune Rhizopodique du Bassin du Léman. In 1905 he wrote that this should be D. lemani Blanc 1892, but test no 3 is in my opinion another species.
Difflugia viscidula
Difflugia viscidula, 292 µm – stacked image
Difflugia viscidula
Difflugia viscidula, 326 µm – 428 µm, Naardermeer, one sample; scale bar = 100 µm.
Difflugia viscidula
Difflugia viscidula, nucleus in squeezed cell. Notice the zoochlorellae and the ingested diatoms.
Difflugia viscidula
Difflugia viscidula, shell ratio Length / Width (n=39)

 

Recent posts

Chlamydophrys-schaudinn

Fritz Schaudinn (1871 – 1906) was a German zoologist. He was the co-discoverer of the causative agent of syphilis and did research on amoebas, particularly

Read More »

Alabasta longicollis

Alabasta longicollis, after Penard, 1890 Alabasta longicollis  (Penard, 1890) Diagnosis: Test pyriform, very elongated (3 times as long as wide), transparent, very little compressed, embedded

Read More »

Alabasta kivuense

Alabasta kivuense, after Gauthier-Lièvre and Thomas, 1961 Alabasta kivuense  Gauthier-Lièvre and Thomas, 1961 Diagnosis: In frontal view, the test is finger-shaped with subparallel sides, the

Read More »

Paulinella micropora

Paulinella micropora, – from Lhee et al., 2017 Paulinella micropora Lhee, Yang, Kim, Andersen & Yoon, 2017 Diagnosis: Test elongate, with five columns of scales,

Read More »

Quadrulella tubulata

Quadrulella tubulata, after Gauthier-Lièvre, 1953 Quadrulella tubulata  Gauthier-Lièvre, 1953 Diagnosis: Shell almost lageniform, compressed, with rounded fundus and more or less irregularly arranged, commonly small,

Read More »

Quadrulella elongata

Quadrulella elongata, after Van Oye, 1952 Quadrulella elongata  Van Oye, 1952 Diagnosis: Test elongated with long neck and square plates, without any pores. Pseudosome slightly

Read More »