Microworld

world of amoeboid organisms

Menu
Planhoogenraadia bonneti
P. bonneti – from Todorov and Golemansky, 1999

Planhoogenraadia bonneti  Todorov and Golemansky, 1999

Diagnosis: The shell is brown, a type of simple cryptostomy, with a flattened ventral side. In dorsal view it is ovoid or ovoid-elongate, and very regular. In lateral view the shell is feebly bulging, with a maximum height near the middle of the length. The invagination of the aperture is shallow (1/6 to 1/5 of the height). The inner lip of the aperture is depressed and the outer lip is incurvate, forming a well differentiated visor. In ventral view the aperture is invaginated, oval, sub-terminal and easily visible. The shell has a comparatively thick wall and it is mainly composed of small, flattish siliceous particles. The arrangement of these particles makes its surface smooth, with a well defined outline.

Dimensions: Length 157-168 µm; width 122-130 µm; height 107-112 µm; aperture 70-75 µm; depth of aperture’s invagination 10-13 µm.

Ecology: humid epiphytic mosses on tree trunks, height 1-2 m. Thailand, “Khao Yai” National Park, 06.07.1995.

Remarks: P. bonneti differs distinctly from the other species of the genera Planhoogenraadia and Hoogenraadia by its biometric characterisation. Planhoogenraadia alta Bonnet, 1984, and Hoogenraadia humicola Bonnet, 1974, are the most closely related species to P. bonneti.
Planhoogenraadia bonneti differs from P. alta by its wider and lower shell. Bonnet (1984) gave the average proportions for P. alta, as follows: Length/Width 1,6 and Height/Width 1,05. These proportions for P. bonneti are L/W 1,3 and H/W 0,87, respectively.
P. bonneti differs from P. alta by a comparatively thick wall of the shell, a brown color, higher shell dimensions and an absence of the small teeth on the dorsal lip of the visor. The two species are distinguished from each other also by their ecology. Bonnet (1984) observed P. alta in forest soils and fertile soils which were rich in organic matter, whereas P. bonneti inhabited humid epiphytic mosses.
Planhoogenraadia bonneti differs from H. humicola by its flattened ventral side and by the larger shell dimensions. Furthermore, the ecology of these species is different, too. Bonnet (1974) indicated that H. humicola inhabited soils rich in organic matter in dense forests of river outfall from tropical regions, whereas P. bonneti was a moss-inhabiting species.
So far Planhoogenraadia bonneti is the only known moss-inhabiting species. From morphological point of view it is also interesting that this species has larger shell dimensions (Length: 157-168 µm) in comparison with the rest of soil-inhabiting species.

Recent posts

Foraminifer drome

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

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 »

Zivkovicia compressoidea

Z. compressoidea, a-b after Chardez, 1958; c after Jung, 1942 Zivkovicia compressoidea  (Jung, 1942) new.comb. Basionym: Pontigulasia compressoidea Jung, 1942 Diagnosis: Shell ovoid and compressed,

Read More »

Zivkovicia flexa

Z. flexa, from Cash and Hopkinson, 1909 Zivkovicia flexa  (Cash and Hopkinson, 1909) Ogden, 1983 Basionym: Pontigulasia compressa var. flexa  Cash and Hopkinson, 1909 Diagnosis:

Read More »

Lagenodifflugia epiouxi

L. epiouxi, after Chardez, 1984 3 Lagenodifflugia epiouxi (Chardez, 1983) new comb. Basionym: Pontigulasia epiouxi Chardez, 1983 Diagnosis: Shell elongate, circular in cross-section or very

Read More »

Centropyxis lapponica

Centropyxis lapponica, after Grospietsch, 1954 Centropyxis lapponica  Grospietsch, 1954 Diagnosis: Shell nearly circular in circumference, without spines. Aperture clear square with rounded corners. Shell viewed

Read More »

Chaos spec. 6

Chaos spec., Crailoo, 2021 Chaos spec. This specimen was found in a samples from Crailoo, Netherlands. It was remarkable because of the absence of crystals.

Read More »

Bullinularia maxima

Bullinularia maxima – from Bobrov and Mazei, 2020 Bullinularia maxima Bobrov et Mazei, 2020 Diagnosis: Shell brown, opaque, elliptical in ventral view; ventral surface is

Read More »