Frenopyxis stierlitzi, Bobrov & Mazei, 2020

Bobrov, Anatoly & Mazei, Yuri, 2020, Frenopyxis stierlitzi gen. nov., sp. nov. - new testate amoeba (Amoebozoa Arcellinida) from the urban parks with notes on the systematics of the family Centropyxidae Jung, 1942, Zootaxa 4885 (3), pp. 384-394 : 385-388

Frenopyxis stierlitzi sp. nov.

( Figs 1–3 ; Table 1)

Description. Shell bilaterally symmetrical, broad elliptic, sometimes almost circular, dorsoventrally flattened, yellowish to colorless; aperture is placed slightly eccentrically on a ventral part of a shell at the bottom of a wide funnel (invagination); aperture usually drop-shaped with narrow side oriented toward closest side; sometimes aperture circular ( Figs 1j ̅l). There is an internal thick organic lip surrounding an aperture and continuing in a bridle, which connects an aperture with the internal side of a shell wall and broaden in the place of connection of a bridle and a shell wall. Shell surface smooth on a ventral side and covered densely by mineral particles on a dorsal side. Organic cement with simple circular pores regularly and densely distributed on the surface. This feature is likely to cause the shell wall to become fragile and thus need to be reinforced by an apertural lip and a bridle connected with a shell wall.

Measurements. Shell length [character 1—see Fig. 3 ]— 37.80–45.90 µm; shell breadth [character 2]— 32.40– 37.80 µm; shell depth [character 4]— 13.50–24.30 µm; distance between the aperture and the top edge of the shell [character 3]— 8.10–15.30 µm; aperture length [character 6]— 8.10–15.12 µm; aperture breadth [character 5]— 6.21–13.50 µm; bridle length [character 7] – 5.40–8.20 µm; bridle breadth [character 8]— 3.24–6.75 µm.

List of associated testate amoebae. Samples from hollows of the Bitsevsky forest contained few species: Trigonopyxis arcula , T. minuta , Centropyxis aerophila , C. delicatula , C. sylvatica v. minor , Cyclopyxis eurystoma v. parvula ; local community from the litter in a shallow hollow of the Tsuga canadensis tree-trunk from Babelsberg Park is more diverse and included Arcella arenaria v. compressa , Centropyxis constricta , C. delicatula , C. sylvatica , Cyclopyxis eurystoma , Trigonopyxis arcula, Phryganella acropodia, Valkanovia elegans, Euglypha anadonta, Corythion dubium, C. pulchellum, Trinema complanatum , and T. complanatum v. elongata .

Type locality. Urban park “Bitsevsky forest”, Moscow (coordinates 55.59° N 37.55° E). Mixed spruce-birchlinden forest. Hollow on spruce tree at a height of 0.5 m. Semi-decomposed litter with a small number of fine mineral particles .

Type specimen. Laboratory of Soil Bioindication, Department of Soil Geography, Faculty of Soil Science , Lomonosov Moscow State University , slide No. 2-2020 .

Etymology. The species is named after Max Otto von Stierlitz one of the lead character in a popular Russian book series written in the 1960s by novelist Yulian Semyonov and of the television adaptation “Seventeen Moments of Spring”, directed by Tatyana Lioznova and starring by Vyacheslav Tikhonov. Stierlitz has become a stereotypical spy in Soviet and post-Soviet culture, similar to James Bond in Western culture. Stierlitz lived in Babelsberg (Potsdam, Germany) where one of the populations of the new species was discovered. Moreover, this name underlines hidden nature of the habitat (viz. tree hollows), where new species was discovered.

Figures

FIGURE 1. Light micrographs of Frenopyxis stierlitzi: a–f, j–l—ventral views, g—ventro-lateral view, h, i—lateral views. Scale bar—20 µm.

FIGURE 2. Scanning electron microscopic image of Frenopyxis stierlitzi: a–d—ventral views, e—dorsal view. Scale bars: a–e—10 µm, f—5 µm.

FIGURE 3. Outline of Frenopyxis stierlitzi: ventral (left) and lateral (right) views. 1–8—characters of the shell measurements. Scale bar: 20 μm.