Meisterfeldia bitsevi, Bobrov & Mazei, 2021

Bobrov, Anatoly & Mazei, Yuri, 2021, Meisterfeldia bitsevi-new testate amoeba of the family Cryptodifflugiidae Jung 1942 (Amoebozoa: Arcellinida) from the tree hollow in the urban park (Moscow Russia) with a key to species of the genus Meisterfeldia, Zootaxa 4908 (4), pp. 595-600 : 596-598

Meisterfeldia bitsevi sp. nov.

( Figs 1–3 ; Table 1)

Description: shell bilaterally symmetrical, elongated oval, laterally not flattened, colorless, transparent. The dorsal side is slightly convex, posterior end curved to ventral side. The aperture is almost circular, placed on the ventral side, which is without any invagination and symmetrically convex as the dorsal side. Shell surface smooth, without mineral inclusions ( Figs 1–3 ).

Measurements: shell length— 30.43–33.40 µm; shell breadth – 15.70–18.10 µm; shell depth—15.80–17.90 µm; aperture width— 5.10–6.20 µm; aperture height— 4.90–6.10 µm ( Table 1).

* Shell measurements are shown in Fig. 3 .

List of associated testate amoebae: Trigonopyxis arcula , Centropyxis aerophila , C. sylvatica , C. sylvatica var. minor , C. eurystoma var. parvula , Plagiopyxis declivis , P. penardi , Schoenbornia humicola , Difflugia nana , Trinema lineare var. minuscula .

Type locality: Urban park “Bitsevsky forest”, Moscow (coordinates 55.59° N 37.55° E). Mixed spruce-birchlinden forest. Hollows on five trees at a height of 1.5 m. Semi-decomposed litter with a small number of mineral particles .

Type specimen: Laboratory of Soil Bioindication, Department of Soil Geography, Faculty of Soil Science , Lomonosov Moscow State University , slide No. 1-2020 .

Etymology: species is named after the name of urban park “Bitsevsky forest”, where it was found for the first time.

Differential diagnosis: from the other species of the genus Meisterfeldia ( Figs 4 , 5 ) new species distinguished by its larger size and lack of lateral compression (in contrast with M. chibisovi, M. wegeneri, M. polygonia), slightly elliptic aperture (in contrast with M. vanhoornei) and lack of pseudostomal neck and apertural collar (in contrast with M. turfacea).

Figures

FIGURE 1. Light micrographs of Meisterfeldia bitsevi: a—ventral view, b—dorsal view, c, d—lateral views. Scale bar—15 µm. Magnification x 400.

FIGURE 2. Scanning electron microscopic image of Meisterfeldia bitsevi: a—ventral view, b—lateral view, c—dorsal view. Scale bar 10 µm. Magnification x 2,500.

FIGURE 3. Outline of Meisterfeldia bitsevi: ventral (left) and lateral (right) views. 1–5—characters of the shell measurements. Scale bar: 15 μm.

FIGURE 4. Comparison of mean shell size of different species from the genus Meisterfeldia.

FIGURE 5. Outlines of the species from the genus Meisterfeldia: a, b—M. bitsevi, c, d—M. chibisovi, e, f—M. wegeneri, g, h—M. vanhoornei, i, j—M. polygonia, k—M. turfacea; a, d, f, h, j—ventral views; b, c, e, g, i, k—lateral views; c–f, i, j—from Bobrov, 2016; g, h—from Beyens et al., 1986; k—from Zacharias, 1903. Scale bar 15 µm.