Microworld

world of amoeboid organisms

Menu
Arcella grospietschi
Arcella grospietschi, after Stepanek, 1963

Arcella grospietschi  Stepanek, 1963

Diagnosis: Shell disc-shaped, yellow-brown, in ventral view with a undulated border, with seven large and seven smaller lobes. Near the aperture, the wall changes into a thinner, skin-like enclosure that is bent back into the interior of the shell. This collar or enclosure is also flap-like, but not as clear as the border of the shell. The edge of the collar is yellowish, not very transparent.

Dimensions: Diameter 132-146 µm, height 28 µm, aperture 35-42 µm.

Ecology: Freshwater. Central Africa.

Remarks: Stepanek (1963): Two shells were found with the plasma, unfortunately after fixation these lost their original shape. Nevertheless, two nuclei and some larger vacuoles were found. A total of 5 shells were found in two locations that were rather far apart from one another, but with the same geographical latitude.

Recent posts

Kibisidytes

K. marinus, after Jepps, 1934 Kibisidytes marinus Jepps, 1934 Diagnosis: Small amoeboid organism occurring in the sea, attached to the surface film or to some

Read More »

Phaeobola

P. aeris from Dumack et al., 2000 Phaeobola Dumack et al., 2000 Diagnosis: Cells roundish to oval shaped. Shell colorless to amber-colored, rough surface, few

Read More »

Rhizaspis armata

R. armata, 68 µm long, excl. spines – Laegieskamp Rhizaspis armata (Lauterborn, 1901) Dumack et al., 2021 Basionym: Pamphagus armatum Lauterborn, 1890 Diagnosis: Theca membranous,

Read More »

Rhizaspis spinosa

The original description with original drawings, Penard, 1890. Rhizaspis spinosa (Penard, 1890) Dumack et al., 2021 Basionym: Trinema spinosum Penard, 1890 Diagnosis: Theca membranous, ovoid

Read More »

Difflugia “pseudoclaviformis”

Difflugia “pseudoclaviformis”, front and side view, 424 µm Difflugia “pseudoclaviformis” Diagnosis: Shell pyriform, compressed, with a more or less pronounced aboral protuberance; shell composed of

Read More »

Difflugia from Lolo Pass

Shells 461-448 µm, stacked image. I found this large en remarkable shells in sediment of a small mountain lake near Lolo Pass, Montana USA. It differs

Read More »

Foraminifer drome

Unknown species, collected from the river Drôme, France, 2021 Unknown species September 2021, I found about ten specimens of an agglutinated foraminifer in a sample

Read More »

Cyclopyxis spec

Cyclopyxis spec., 168 µm Cyclopyxis spec. Diagnosis: Shell circular in ventral and dorsal view, more or less hemispherical in lateral view (height/diameter ≈ 0.5); lateral

Read More »

Difflugia fallax

Difflugia fallax, from Penard, 1902 Difflugia fallax Penard, 1890 Diagnosis: Shell hyaline or yellowish-greenish, black at low magnification, round in cross section, formed of a

Read More »