Water mites of the genus Unionicola Haldeman, 1842 (Acari, Hydrachnidia, Unionicolidae) in Russia Author Tuzovskij, Petr V. Author Semenchenko, Ksenia A. text Zootaxa 2015 3919 3 401 456 journal article 10.11646/zootaxa.3919.3.1 dec3bc79-023d-454e-9ed8-4dfb8c3f0b6a 1175-5326 241378 FF49DAFE-EA8E-473B-9F3D-CEB670B4882B Unionicola markovensis Tuzovskij, 1990 ( Figs 12A–D , 13A–D ) Material examined. 2 male , 4 females : Russia , Magadan Province, Tenkinsky District, small lakes near village Agrobasa, June–July 1979 ; 1 female , Chukotka Autonomous Okrug, Anadyr District, small lake near settlement Markovo, 29.07.1981 , leg. P.V. Tuzovskij. All males and females are collected free-swimming. Diagnosis. Adults. Dorsum with two pairs of unequal platelets; medial margin of coxal plates III+IV straight and longer than their width; P-3 with two subequal setae, base of lateral seta located proximally to middle of segment, P-4 with very long lateral tubercle and two relatively short ventrolateral tubercles, P-5 curved; anterior plates of female with long, thick unequal medial setae, posterior plates with long, thick medial setae; genital plates of male relatively narrow, fused to each other by posterior ends only; swimming setae on IV-Leg-5 slightly shorter than IV-Leg-6; claws of legs I thick, hook-like, claws of legs II–IV thin, sickle-shaped. Description. Both sexes . Dorsum with two pairs of unequal platelets ( Fig. 12A ), anterior platelets relatively large, elongate; posterior platelets oval or circular and considerably smaller than anterior ones. Anterior and posterior coxal groups ( Fig. 12B ) divided by wide interspace; sclerites, bearing setae and glandularia Le , much larger than sclerites bearing other idiosomal setae. Apodemes of first coxal group reaching or slightly extending beyond to anterior margin of third coxae. Coxal plates III+IV elongated (L/W ratio 1.3–1.8) with straight medial margin, posterior margin of coxal plate IV oblique directed posterolaterally. Surface of all coxal plates with reticulations. Pedipalps ( Fig. 13A ) rather slender: P-2 with nearly straight ventral margin with three to four proximal setae and single dorsodistal short seta; P-3 with long lateroproximal and relatively short dorsodistal setae; P-4 with long lateral and two relatively small subequal tubercles; bases of lateral and anterior ventral tubercles situated near middle of segment; P-5 curved and shorter than P-4 (P-4/P-5 L 1.10–1.25), all simple thin setae and spines short and located distally. Legs II–IV long, slender. The number of distal swimming setae on legs IV is as follows ( Fig. 13B ): three on genu and on tibia. Swimming setae on leg II shorter than swimming setae on legs III–IV. Claws of legs I ( Fig. 13C ) hook-like with two unequal clawlets, claws of legs II–IV ( Fig. 13D ) sickle-shaped with short dorsal clawlet and long ventral one. FIGURES 12A–D. Unionicola markovensis , adults: A, dorsal plates; B, coxal plates; C–D, genital field; A–C, female; D, male. Scale bars: A–B = 200 Μm, C–D = 100 Μm. Female. Anterior and posterior genital plates nearly subequal in shape and size ( Fig. 12C ), anterior plate without anterior subcutaneous projections, with long, thick unequal medial setae; posterior plate with long anteromedial seta and 4–5 short, thin setae. All acetabula moderately in size and occupy less than one half of area of each genital plate. Measurements (n=5). Idiosoma L 800–1075; coxae III+IV L 335–350, W 250–275; anterior dorsal platelets L 80–90, W 20–25; anterior genital plates L 75–90, W 80–90; posterior genital plates L 85–90, W 85–90; pedipalpal segments (P-1–5) L: 30–40, 170–195, 89–98, 155–165, 120–145; leg segments L: I-Leg- 1–6—95 –120, 300–330, 340–385, 445–500, 340–385, 305–350; II-Leg- 1–6—95 –115, 300–345, 415–465, 500–575, 560–640, 430–485; III-Leg-1–6—100–105, 265–295, 290–345, 350–395, 420–475, 365–385; IV-Leg-1–6—160–180, 285–310, 350–395, 455–500, 585–660, 485–565. Male . Genital plates ( Fig. 12D ) rather wide, fused to each other by posterior ends, with 9–10 thin setae on each side, in additional, one pair of genital setae located on soft integument; anterior ends of plates widely rounded. All acetabula approximately equal in size and occupy less than one half of area of each plate. Measurements (n=2). Idiosoma L 780–1025; coxae III+IV L 285–300, W 225–250; genital field L 185–215, genital plate W 73–76; pedipalpal segments (P-1–5) L: 28–33, 138–147, 80–82, 135–140, 110–115; leg segments L: I-Leg- 1–6—95 –105, 265–280, 300–310, 405–415, 305–320, 285–305; II-Leg- 1–6—80 –95, 265–285, 390–400, 480–500, 495–530, 395–410; III-Leg- 1–6—80 –85, 235–245, 275–285, 330–340, 390–400, 330–345; IV-Leg- 1–6—130–140, 250–260, 320–385, 430–445, 550–565, 450–465. Deutonymph . See Tuzovskij (1990) . Larva . See Tuzovskij (2014) . Habitat. Lakes. Hosts. Unknown. Distribution. Russia : Magadan Province, Chukotka Autonomous Okrug ( Tuzovskij 1990 ).