Wandesia (Wandesia) sokolowi, Semenchenko, Ksenia A., 2016

Semenchenko, Ksenia A., 2016, New water mites species (Acariformes: Hydrachnidia) from interstitial waters of the Russian Far East, Zootaxa 4097 (4), pp. 545-556 : 547-550

Wandesia (Wandesia) sokolowi sp. n.

( Figs 2A–D , 3A–H )

Type series. Holotype: male ( X 44820 /Ar-27), Russia, Primory Territory, Artemovsky Urban District, Steklyanukha River, N 43°21.027’; E 132°27.723’; depth 30 cm below the sediment surface; substrate: cobbles, pebbles, coarse- and medium-grained sand; 12.06.2010, leg. K.A. Semenchenko, D.A. Sidorov. Paratypes: 2 males ( X 44852 /Ar-30), 3 females ( X 44853 /Ar-31), same data as holotype; 1 male ( X 44854 /Ar-32), Russia, Primory Territory, Partizansky District, Partizanskay River basin, Tigrovaya River, N 43°11.401’; E 133°12.660’; depth 30 cm below the sediment surface; substrate: cobbles, pebbles, sand; 12.06.2010, leg. K.A. Semenchenko, D.A. Sidorov. Additional material examined (not included in the type series; not mounted, in Koenike’s fluid): 4 males, same data as holotype.

Diagnosis. Adults. P-5 with very long proximal solenidion. Cx-IV well developed, with medial part reaching medial part of Cx-III. Ac-2 longer than Ac-1 and slightly shorter than Ac-3. Setae Ci located on the level of excretory pore.

Description. Both sexes. Idiosoma elongated ( Figs 2A, B ). Integument reticulated; Cx-I and II fused in medial part ( Fig. 2C ); Cx-III with broad medial edge and short anteromedial apodeme; Cx-IV well developed; Cx-I with three setae; Cx-II without setae; Cx-III with one-two setae and Cx-IV with one anterior seta. Genital field ( Fig. 2D ) with three pairs of stalked elongated genital acetabula. Distance between Ac-1 and Ac-2 twice longer than between Ac-2 and Ac-3, Ac-1 shorter than posterior pairs of acetabula. Males with nearly transparent sclerites projected above Ac-1, bearing 13–14 pairs of setae ( Fig. 2D ); females only with two visible pairs of setae on wrinkles of integument ( Fig. 3A ). Gonopore between first pairs of acetabula. Male’s ejaculatory complex as illustrated on Figs 3B–C . Excretory pore elongated, located posteriorly on ventral side between setae Ci. Gnathosoma anteriorly with papillae ( Fig. 3D ). Pedipalps short ( Fig. 3E ). P-1 without setae; P-2 with one lateral and two dorsodistal short setae; P-3 with two long dorsodistal setae; P-4 with large dorsodistal spine and three thin distal setae (dorsal setae absent on pedipalp of holotype); P-5 with very long proximal solenidion. Chelicera ( Fig. 3F ) with large chela. Anterior pairs of legs wider than posterior ( Figs 3G, H ). Claws simple hook-like.

Male. Measurements (n=2). Idiosoma L 1260–1580, Cx-I+II total L 105–108, W 82–92, Cx-III+IV lateral L 73–84; Ac-1 L 25–27, W 16–19, Ac-2 L 34–37, W 17–18, Ac-3 L 39–55, W 16; ejaculatory complex L 121–125; gnathosoma vL 154–211, chelicera basal segment L 127–138, claw L 75–78, L basal segment/claw ratio 1.7; pedipalpal segments (P–1–5) L: 23–24, 46–51, 40–41, 51–56, 12–13; leg segments L: I–Leg– 1–6 —45 –46, 94–95, 78–84, 84–89, 93–107, 94–106; II–Leg– 1–6—46 –48, 76–89, 71–75, 78–84, 92–100, 93–105; III–Leg– 1–6—36 – 38, 67–68, 48–54, 62–65, 76–81, 89–92; IV–Leg– 1–6—51 –60, 70–78, 72–78, 84–89, 86–92, 89–94.

Female. Measurements (n=2). Idiosoma L 1400–1500, Cx-I+II total L 119–124, W 70–100, Cx-III+IV lateral L 100–113; Ac-1 L 32–35, W 19–22, Ac-2 L 45–46, W 17–25, Ac-3 L 51–57, W 18–23; gnathosoma vL 108–130, chelicera basal segment L 154–157, claw L 84–89, L basal segment/claw ratio 1.7–1.8; pedipalpal segments (P–1– 5) L: 21–29, 54–55, 35–40, 58–59, 15–16; leg segments L: I–Leg– 1–6—51 –52, 97–105, 81–86, 90–92, 103–108, 102–108; II–Leg– 1–6—46 –49, 94–95, 75–81, 83–84, 97–100, 105–108; III–Leg– 1–6—36 –38, 60–68, 49–56, 64– 65, 81–89, 93–96; IV–Leg– 1–6—56 –60, 75–78, 76–84, 86–92, 94–95, 92–100.

Differential diagnosis. Three known species from the subgenus Wandesia , i.e.— W. polyseta Tuzovskij, 1982 , W. morozovensis Tuzovskij, 1987 and W. japonica Imamura, 1956 have solenidion on P-5 which is much longer than its length. Wandesia polyseta was described on the basis of a deutonymph ( Tuzovskij 1982), and characterized by multiple idiosomal setae. Wandesia sokolowi sp. n. is closely related to W. morozovensis , known from Magadan Region. The new species differs from the latter in the following characters (character states of W. morozovensis are given in parentheses, data taken from Tuzovskij 1987b): Cx-IV well developed (weakly developed, with medial part not reaching medial part of Cx-III); Ac-2 longer than Ac-1 and slightly shorter than Ac-3 (Ac-2 shorter than other pairs of acetabula); setae Ci located on the level of excretory pore (posterior to excretory pore). Males of the new species differ from W. japonica in having elongated acetabula (in Fig. 2 from Imamura 1956 all acetabula are rounded), 13–14 pairs of genital setae (6 pairs in W. japonica ) and broader Cx-IV.

Etymology. The species is named after Professor Ivan Ivanovich Sokolow (1885–1972) in appreciation of his studies on water mites of the Russian Far East.

Distribution. Primory Territory, Far East of Russia.

Figures

FIGURE 2 A – D. Wandesia sokolowi sp. n. (males: A – B = not mounted specimen, C = holotype, D = paratype): A. Dorsal view. B. Ventral view (genital acetabula, coxal and genital setae are not illustrated). C. Coxal and genital field. D. Genital field. Scale bars: A – C = 100 Μm, D = 25 Μm.

FIGURE 3 A – H. Wandesia sokolowi sp. n.: A. Genital field of female paratype. B – C. Ejaculatory complex of not mounted male, anterior (B) and lateral (C) view. D. Gnathosoma of male holotype. E. Pedipalp of male holotype, lateral view. F. Chelicera of male paratype. G. Leg I of male paratype. H. Leg IV of male paratype. Scale bars: F – H = 50 Μm, A – E = 25 Μm.