world of amoeboid organisms

Menu
Shells in side view (left and right) and in frontal view (center). These shells came from a ditch with clay bottom near Montfoort, the Netherlands. All shells were c. 79-104 µm in length.

Difflugia balcanica  Ogden and Zivkovich, 1983
= D. biconcava Ertl, 1965 ?

Diagnosis: Shell ovoid or pyriform, with an aboral rounded cone or spine and laterally compressed; shell in lateral view with typical biconcave shape; aperture circular;  shell composed of a mixture of small to large pieces of mainly flattish quartz, arranged to give a relatively smooth surface.

Dimensions: Ogden and Zivkovich: 111-114 µm long, 79-82 µm broad, aperture 31 µm (n=2). My measurements: 78-104 µm (n=10).

Ecology: I found this species in sediment of a ditch near Montfoort, the Netherlands.

Remarks: When this species was described, Ogden and Zivkovic were, according to their remarks, unaware of the description of  D. biconcava Ertl, 1965 (“There does not appear to be any prior descriptions of any similar compressed species of Difflugia, and D. balcanica is considered to be distinct in having a leaf-like shape, with an angular surface and a pointed aboral extremity”). D. biconcava is a very similar, but larger species. Ertl: 100-143 µm long, 66-96 µm broad, aperture 29-32 µm. My measurements: Naardermeer 149-190 µm (n=8); nucleus 31-39 µm; (n=2). Probably both species are identical.

Difflugia balcanica
D. balcanica, published by Ogden and Zivkovic, 1983.
Difflugia biconcava
Difflugia biconcava, published by Ertl, 1965. This species is very similiar to D. balcanica, but larger (Ertl: 100-143 µm; my measurements 149-190 µm).
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 »