Porosia paracarinata, from Bobrov and Kosakyan, 2015

Porosia paracarinata Bobrov and Kosakyan, 2015

Diagnosis: Test large, pyriform, laterally compressed, with a rounded posterior part, narrow elliptical in profile. At approximately 1/3 of test length starting from the aperture, two distinct lateral depressions with two large invaginated pores are situated on each side, which are connected by internal tubes as in Porosia bigibbosa. In profile, small lateral pores can be observed, just anterior to the large pores. At approximately after 1/2 of the length of the test counted from the aperture, a lateral keel emerges such as in Planocarina (Nebela) carinata, the width of which can vary between individuals. Test colorless, composed of circular or elliptic or irregular plates, often covered by a thin layer of organic cement. Aperture oval, curved, surrounded by a thick organic lip.

Dimensions: Length 202-236 µm, Breadth 142-157 µm, aperture 56-67 µm wide.

Ecology: Porosia paracarinata was found in wet leaves (forest litter) in a mixed forest of Fagus sp. and Cider japonica, Japan.

Remarks: Morphometric analyses of Porosia paracarinata show that species is characterized by low variability. The largest standard deviation (SD) was observed in test length. The most stable morphological character is the thickness of the organic lip surrounding the aperture. The width of the lateral keel can also be variable among the individuals starting from very narrow (3.75 µm) to very wide (13.13 µm).

Reference: Bobrov, A. and Kosakyan, A., 2015: A New Species from Mountain Forest Soils in Japan: Porosia paracarinata sp. nov., and Taxonomic Concept of the Genus Porosia Jung, 1942 – Acta Protozool. 54: 289-294.

Recent posts

Microcorycia spec. 4

Microcorycia spec. , folded Microcorycia spec.? I found this specimen in a sample from moss on a fallen tree in a marsh in the Naardermeer,

Read More »

Microchlamys spec.

Microchlamys spec., the same cell in lateral view Microchlamys spec. Diagnosis: Shell relatively high compared with all described species. The diameter is twice the height.

Read More »


Infraorder Excentrostoma Kosakyan et al., 2016   Diagnosis: Testate amoebae with an eccentrically placed aperture; test organic with few or many xenosomes. Family Centropyxidae Jung, 1942  

Read More »


Infraorder Longithecina Kosakyan et al., 2016   Diagnosis: Testate amoebae with a more or less tubular or cylindrical test and a terminal aperture; test with

Read More »