Sperchon (Sperchon) tuzovskiji Pešić & Smit, 2020

Tuzovskij, Petr V., 2023, On the systematic of the water mite Sperchon tuzovskiji Pešić & Smit, 2020 (Acari, Hydrachnidia: Sperchontidae), Zootaxa 5296 (3), pp. 497-500 : 497-498

Sperchon (Sperchon) tuzovskiji Pešić & Smit, 2020

( Figs 1–11 )

Material examined. Male, slide 9940, Asia, Kazakhstan, Turkestan Province, Tyulkubaskiy District, Aksu-Zhabagly Nature Reserve , Taldybulak stream, 42°24′04.4″N 70°28′13.7″E, 1450 m, depth about 1 m, substrates large stones, mosses, white sand, 10.08.2019, leg. V. Stolbov .

Description. Male. Integument dorsally and latero-ventrally rugose with flat papillae, interspace between posterior coxal groups and excretory pore striated. Muscle attachment plates unsclerotized, all glandularia on small platelets ( Fig. 1 ). Setae Fch ( Fig. 2 ) thick, shorter than length of sclerites to which attached. Trichobothria Fp and Oi located on very small sclerites, sclerites Oi larger than Fp but both trichobothria smaller than others glandularia and eye capsules. Anterior coxal groups medially close to each other but not fused, apodemes slightly developed ( Fig. 3 ). Sclerites bearing setae Hv situated near posterolateral angles of coxal plates II. Posterior coxal groups medially well separated, medial margin of coxal plates III narrow; glandularia and setae Pe separated, glandularia open at anteromedial angle, and seta near posteromedial angle. Medial margin of coxal plates IV rounded. Genital field situated between posterior coxal groups, pregenital sclerite close to anterior genital sclerite ( Fig. 4 ). Anterior and posterior genital sclerites very small and subequal in shape and size. All genital acetabula elongate narrow but ac-3 shorter than ac-2 and ac-1, ac-1/2 and ac-2/3 located close to each other, respectively. Genital flaps elongate (L/W ratio 2.5), with 19–20 medial and six lateral fine setae each. Excretory pore surrounded by sclerotized ring, located at level of setae Ci ( Fig. 5 ).

Gnathosoma ( Fig. 6 ) with rather long rostrum, posterior margin slightly concave, both pairs of hypostomal setae subequal in length. Basal segment of chelicera large, chela short crescent-shaped, ratio basal segment/claw 5.0 ( Fig. 7 ). Pedipalp ( Fig. 8 ): P-1 short, with single dorsal seta; P-2 expanded dorso-ventrally with long distoventral projection, at its tip bearing two fine setae, near base of projection there is a stout seta which is shorter than the projection; P-3 large, tapering distally, with almost straight ventral margin, and bearing three proximal and one to two dorsodistal setae; P-4 comparatively slender, with two ventral tubercles, bearing peg-like setae, proximal tubercle a little larger than distal one, area between peg-like setae subdivides ventral margin into three unequal parts, medial part shorter than proximal and distal ones. Leg segments slender, III/IV-L without plumose dorsal setae ( Fig. 9 ). Ambulacrum with claw blade well protruding, bearing a long external and a shorter internal clawlet ( Fig. 10 ).

Measurements. (n=1). Idiosoma L 870; distance between anterior end of Cx-I and posterior end of Cx-IV 335; coxal plates III W 175; genital flap L 150, W 62, pregenital sclerite W 20; genital acetabula (ac-1-3) L/W 50/25, 62/25, 40/18; capitulum L 200, rostrum L 70; cheliceral segments: base L 225, chela L 45; pedipalp total L 459, pedipalp segments (P-1-5) L/H, L/H ratio: 37/50, 0.74; 112/125, 0.9; 135/100, 1.35; 150/31, 4.8; 25/31, 0.8; legs segments L: I-Leg-1–6: 50, 62, 80, 125, 125, 135; II-Leg-1–6: 55, 62, 100, 150, 155, 150; III-Leg-1–6: 62, 85, 125, 225, 210, 200; IV-Leg-1–6: 100, 110, 125, 225, 210, 200.

Remarks. The male of Sperchon tuzovskiji Pešić & Smit, 2020 is similar to the female but smaller in size, and differs by a structure of the genital field. The genital flaps in the female ( Fig. 11 ) with 14 medial setae, ac-1–2 well separated, and ac-2–3 located close to each other ( Pešić & Smit 2020); while in the male genital flaps with 19–20 medial acetabula, ac-1–2 and ac-2–3 located close to each other, respectively ( Fig. 4 ).

Distribution. Asia, Kyrgyzstan ( Pešić & Smit 2020), Kazakhstan this study.

Figures

FIGURES 1–7. Sperchon tuzovskiji, male: 1, idiosoma dorsal view; 2, seta Fch; 3, idiosoma ventral view; 4, genital field (fragment), 5, excretory pore and setae Ci, 6, capitulum, ventral view; 7, chelicera, ventral view. Scale bars: 1 = 200 μm, 2, 4-5 =50 μm, 3, 6-7 = 100 μm,

FIGURES. 8–11. Sperchon tuzovskiji, 8-10, male: 8-10: 8, pedipalp; 9, IV-Leg-4-6; 10, leg claw. Female: 11, ventral view (from Pešić & Smit 2020). Scale bars: 8, 10 = 50 μm, 9, 11 = 100 μm.