Microworld

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

Penardochlamys arcelloides

P. arcelloides – from Penard, 1904 Penardochlamys arcelloides  (Penard, 1904) Deflandre, 1953 Diagnosis: Colorless or very slightly yellowish envelope, bag or cauldron-shaped, very thin, chitinous,

Read More »

Reticulomyxa hannae

R. hannae, plasmodium – photomicrograph Steffen Clauss Reticulomyxa hannae Völcker and Clauß, 2020 Diagnosis: Trophozoites surrounded by a very thin mucous envelope, with slowly moving plasmodia, variable

Read More »

Velamentofex saxonensis

V. saxonensis, feeding (photomicrograph Steffen Clauss) Velamentofex saxonensis Völcker and Clauß, 2020 Diagnosis: Trophozoites ovoid, 30-95 μm, granuloreticulopodia up to 1000 μm long. with a hyaline, thin

Read More »

Velamentofex tyrolensis

V. tyrolensis (photomicrograph Steffen Clauss) Velamentofex tyrolensis Völcker and Clauß, 2020 Diagnosis: Trophozoites ovoid, 98-125 μm, with reticulopodia up to 300 μm long, with a hyaline,

Read More »

Velamentofex berolinensis

V. berolinensis Velamentofex berolinensis Völcker and Clauß, 2020 Diagnosis: Trophozoites ovoid, 50-300 µm, with a hyaline, extremely flexible, membranous test. Nuclei numerous, 11.6-16.2 µm in diameter,

Read More »

Lieberkuehniidae

 Lieberkuehniidae  Siemensma, Holzmann, Apothéloz-Perret-Gentil, Clauß, Voelcker, Bettighofer, Khanipour Roshan, Walden, Dumack and Pawlowski, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test very flexible, elongated to broadly

Read More »