Microworld

world of amoeboid organisms

Menu

Below the original description of Pyxidicula invisitata by Awerinzew (1906), translated from Russian by Yana Eglit:

The test in its form is reminiscent of the previous species (P. cymbalum): its height is likewise smaller than the diameter, and the oral aperture occupies the entire ventral surface of the test, and thus the oral diameter matches that of the test.
Under higher magnifications (Zeiss objective E, occular 4) one can resolve a cellularised/mesh-like structure of the test, by combining pictures of longitudinal (table V fig 63) and transverse optical sections.
P. invisitata differs from P. cymbalum in its diminutive size, and, most importantly, that the little lip surrounding the shell attaches to its outside surface in the former — a bit removed upwards from the edge of the test. As a result, the test of P. invisitata in its transverse section resembles an arc with bifurcating ends (table V fig 61, 62). The nucleus is vesicular with one nucleolar body (table V fig 64).

Diameter of P. invisita test = 0.040-0.050 mm
Habitat: swampy creeks
Russia (Archangel’sk region)

Pyxidicula invisitata

Fig 61. Overall semi-schematic view of the P. invisitata.
62. Optical transverse section of the test.
63. Part of the test with its surface.
64. The nucleus.

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 »