Planhoogenraadia daurica Bobrov, 2000
Diagnosis: Test large, gray, with simple cryptostomy. In dorsal view ovoid with pseudostome in the smaller part of the test. Dorsal side flat. Visor extends beyond the dorsal plane. In lateral view the aboral part bulges slightly and gradually towards the ventral plane. The maximum height is approximately in the middle of the test. The outline of the dorsal part of the test is smooth, without constrictions. The aperture is about 1/5 of the height of the test. In light microscopy there are two or three sharp teeth visible on the dorsal lip. The test is covered by flat translucent mineral plates of irregular shape with inclusions of detritus and rarely brownish hyphae of fungi.
Dimensions: Length 130— 145 µm; height 86-90 µm; width 100-102 µm; length-height ratio 1.5; length/width 1.3; distance between the end of the dorsal lip and the contour line of the ventral surface 8-9 µm; pseudostome 36 x 15 µm (n = 10).
Habitat and distribution: Brown forest light loamy soil. Mull-type humus. Russia (Far East: Primorskii Krai).
Remarks: Differential diagnosis: From the closely related species Р. alta and P. cantabrica, Р. daurica can be distinguished by following morphological characteristics:
1) the less deep cut pseudostome, 1/5 of the height (width) of the shell (P. alta: 1/3; P. cantabrica: 1/6 to 1/3);
2) a larger carapace; the length is 2 times larger than in P. cantabrica and one-quarter more than in P. alta;
3) a wider pseudostome;
4) The aboral end is not narrowed as with P. cantabrica and P. alta. The widest part of P. daurica is at the beginning of the lower third of the shell, while the other two species has their widest part at the first part or the middle part of the shell;
5) in contrast to P. сапtabrica is no slight constriction that separates the abdomen from the visor;
6) the ratio of the length and width is 1.3 and 1.7 at P. cantabrica, 1.6 at P. alta;
7) In contrast to P. cantabrica and P. alta the dorsal lip extends beyond the ventral plane.
References: Bobrov, A.A., Planhoogenraadia daurica Bobrov, a New Testate Amoeba Species from Primorsky Krai (Far East), Zool. Zhurn., 2000, vol. 79, no. 1, pp. 108–110.