Porosia paracarinata Bobrov et Kosakyan

User, GBIF. Org, 2015, A New Species from Mountain Forest Soils in Japan: Porosia paracarinata sp. nov., and Taxonomic Concept of the Genus Porosia Jung, 1942, Acta Protozoologica 54 (4), pp. 289-294 : 290-291

Porosia paracarinata Bobrov et Kosakyan ( Figs 2 , 3 , 4 )

Diagnosis: Test large, pyriform, laterally compressed, with rounded posterior part, narrow elliptical in profile. At approximately 1/3 of test length starting from 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 aperture, a lateral keel emerges such as in Nebela carinata , the width of which can vary between individuals (see Table 1, Figs 3 , 4 ). Test is colorless, composed of circular or elliptic or irregular plates, often covered by the thin layer of organic cement. Length = 202–236 µm, Breadth = 142–157 µm. Aperture is oval, 56–67 µm wide, curved, surrounded with a thick organic lip.

Morphometry and morphological variability: Morphometric analyses of Porosia paracarinata show that species is characterized by low variability ( Table 1). 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, see Fig. 4 ) to very wide (13.13 μm, see Fig. 3 ).

Ecology: Porosia paracarinata inhabits wet leaves (forest litter layer A0 or L-layer) in the mixed forest of Fagus sp. and Cider japonica .

A New Testate Amoeba from the Soil in Japan 291

Figures

Fig. 2. Outline of Porosia paracarinata: ventral (left) and lateral (right) views. 1–7 – measured characters of the test (see Table 1). Scale bar: 50 µm.

Fig. 3. Porosia paracarinata sp. nov. A – SEM image of P.paracarinata with wider keel; B – LM image of P. paracarinata with wider keel; C – P. paracarinata in profile view; D – schematic draw of P. paracarinata. Scale bars: 50 μm.

Fig. 4. Keel variation in Porosia paracarinata sp. nov. A – SEM image of P. paracarinata with narrow keel; B – LM images of P. paracarinata with narrow; C – very narrow and D – almost disappearing keel. Scale bars: 50 μm.