Schoenbornia
Schoenbornia Schonborn, 1964
Rhizopoda (ref. ID; 2862)
Synonym Pseudonebela Schonborn, 1964 (ref. ID; 2056)
- Schoenbornia humicola Decloitre (ref. ID; 2818) or (Schonborn, 1964) Decloitre, 1964 (ref. ID; 2030, 2057, 4737) reported year? (ref. ID; 3383)
Syn; Pseudonebela humicola Schonborn, 1964 (ref. ID; 2057)
- Schoenbornia smithi Beyes & Chardez, 1997 (ref. ID; 2818 original paper)
- Schoenbornia viscidula Schonborn, 1964 (ref. ID; 2057, 2862, 4755) reported year? (ref. ID; 2818, 3383)
Schoenbornia humicola Decloitre (ref. ID; 2818) or (Schonborn, 1964) Decloitre, 1964 (ref. ID; 2030, 2057, 4737) reported year? (ref. ID; 3383)
Synonym
Pseudonebela humicola Schonborn, 1964 (ref. ID; 2057)
Descriptions
The shell is small, colourless, transparent, elliptical or ovoid with a rounded aboral region, circular or slightly compressed laterally. The pseudostome is terminal, circular or roughly circular. Light and scanning electron microscopy showed that a great but variable part of the shell consists of idiosomes of various euglyphids. These foreign idiosomes are placed irregularly on the shell. Besides the foreign idiosomes the shell of S. humicola also contains irregular scales. In the polarizing microscope these scales appear as amorphous siliceous elements and angular quartz. The origin of these element is unknown. It is supposed that the siliceous elements can be produced in the cell, because they can be deposited in the cytoplasm. S. humicola incorporates great quantities of detritus (humus particles). Before incorporation the detritus is collected around the pseudostome in the form of bundles. (ref. ID; 2030)
Cyst: Resting stage occur as cysts and precysts. Cysts are spherical and enclosed in a thick membrane. They are distinctly separated from the shell wall. Precysts are very similar to those of the euglyphids as described by Volz (1929). They have a retracted cytoplasm, which closely adjoins the shell wall, and is surrounded by a thin membrane. A bubble between the pseudostome plug and the retracted cytoplasm could be observed in precysts during long lasting periods of low moisture content of the soil. These shells stand upright with the pseudostome downward in soil suspension. Shells with cysts as well as precysts have their pseudostome sealed by a thin membrane (diaphragm), often covered with detritus. The detritus can be very dense and appearing as a plug. In such cases the diaphragm is not visible. In addition to detritus, amorphous siliceous platelets can be found in the sealed pseudostome. (ref. ID; 2030)
Schoenbornia smithi Beyes & Chardez, 1997 (ref. ID; 2818 original paper)
Descriptions
The shell is oval, circular in cross-section. The short circular collar is bordered by irregular formed mineral particles. The shell wall is composed of a thick organic layer, encrusting some thin polymorphic inorganic particles. The shell is transparent or yellow. A thick-walled spherical cyst with diameter of 26 µm has been observed. (ref. ID; 2818)
Comments
This species is distinguished from the other two species from this genus (Sch. viscidula Schonborn and Sch. humicola Decloitre) by the presence of the collar with mineral particles, and the structure of the shell. It is clearly bigger then Sch. humicola. The habitat is also different, the two other species living in a terrestrial environments. (ref. ID; 2818)
Measurements
Length of shell 37-40; diameter of shell 26-30; diameter of aperture 15-18 µm (n=10). (ref. ID; 2818)
Schoenbornia viscidula Schonborn, 1964 (ref. ID; 2057, 2862, 4755) reported year? (ref. ID; 2818, 3383)
Descriptions
Shell slightly compressed, composed of irregular flat platelets with agglutinated rough xenosomes. Aperture circular, nucleus with a central nucleolus. (ref. ID; 4755)
Measurements
Schonborn (1964) states a mean value of 8.6 µm for the diameter of the aperture, the corresponding value of our population is 5 µm. Wanner (1987) describes an oval aperture, which shows the greatest variability of the investigated parameters. (ref. ID; 4755)