Unionicola ypsilophora (Bonz, 1783)

Tuzovskij, Petr V. & Semenchenko, Ksenia A., 2015, Water mites of the genus Unionicola Haldeman, 1842 (Acari, Hydrachnidia, Unionicolidae) in Russia, Zootaxa 3919 (3), pp. 401-456 : 448-450

Unionicola ypsilophora (Bonz, 1783)

( Figs 41A–D , 42A–F )

Material examined. 1 male, 1 female: Russia, Yaroslavl Province, Nekouz District, Rybinsk reservoir near settlement Borok, October 2013, leg. O.D. Zhavoronkova; 1 female: Russia, Amurskaya Area, Archarinsky Region, Antonovskoe reservoir, from Amuranodonta kijaensis Moskvicheva, 0 4.06.2009, leg. E.M. Saenko. Additional material: 1 male, 1 female: Ukraine, Odessa Province, Danube River near settlement Vilkovo, 0 3.07.2011, leg. L.N. Yanovich, T.V. Shevchuk; 2 males and 2 females (slides) in collection of the Senckenberg Museum, Frankfurt on Main ( Germany).

Diagnosis. Adults. Coxal plates III+IV elongated with straight or slightly convex medial margin; P-3 with two long subequal setae, P-4 with very small lateral tubercles, both ventral tubercles very small, P-5 relatively short with three unequal distal spines; legs IV with sexual dimorphism, swimming setae on IV-Leg-5 shorter than IV- Leg-6; claws of all legs with two subequal clawlets; female—dorsum with two pairs of small platelets, all three inner setae on both genital plates long and subequal; male—dorsum with large plate, genital plates wide fused to each other by anterior and posterior ends, genital acetabula occupy about one half of each genital plate.

Description. Both sexes. Anterior and posterior coxal groups ( Fig. 41B, D ) divided by narrow interspace, sclerites, bearing setae and glandularia Le, small, nearly subequal with sclerites bearing idiosomal setae (Pe, Hv), other idiosomal setae not associated with glandularia. Apodemes of first coxal group short reaching or slightly extending beyond to anterior margin of third coxae. Coxal plates III+IV elongated (L/W ratio 1.42–1.50) with straight or slightly convex medial margin. Surface of all coxal plates with reticulations.

Pedipalps ( Fig. 42C ) moderately in size: P-2 large with convex ventral margin and five unequal setae;P-3 with two subequal setae (proximal and distal); P-4 with three minute tubercles; P-5 short (P-4/P-5 L2.1–3.0) with one solenidion, four thin simple setae and three distal spines, solenidion and two simple setae located proximally to middle of segment.

Legs II–IV long, slender. The number of distal swimming setae on legs IV is as follows ( Fig. 42D ): three on IV-Leg-4 and four on IV-Leg-5. Swimming setae on IV-Leg-5 shorter than IV-Leg-6. Claws of all legs bifid with subequal clawlets, but claws of leg I ( Fig. 42E ) smaller than claws on other legs ( Fig. 42F ).

Female. Dorsum usually with two pairs of unequal platelets ( Fig. 41A ), anterior platelets much larger than posterior ones, the last sometimes not developed. Genital field with two large platelets ( Fig. 42B ), with 14–20 acetabula, three long, thick inner and seven to eight short, thin setae on each side. All acetabula moderately in size and occupy less than one half of each genital plate.

Measurements (n=4). Idiosoma L 1500–2650; coxae III+IV L 625–750, W 375–390; anterior dorsal plate L 200–225, W 35–55; genital field L 205–240, W 230–240; pedipalpal segments (P-1–5) L: 25–35, 200–230, 75–105, 150–165, 60–90; leg segments L: I-Leg-1–6—110–130, 125–220, 185–210, 250–290, 235–250, 155–180; II-Leg-1–6—110–130, 150–180, 270–280, 335–405, 325–365, 260–300; III-Leg-1–6—110–120, 125–215, 220–240, 285–325, 300–330, 260–275; IV-Leg-1–6—185–240, 175–240, 285–315, 475–490, 600–625, 490–515.

Male. Dorsum with large plate ( Fig. 41C ). Genital plates ( Fig. 42A ) wide, fused to each other by anterior and posterior ends, with 20–22 acetabula and 6–8 short, thin setae on each side. All acetabula subequal and occupy about one half of area of each plate.

Measurements (n=4). Idiosoma L 1100–2100; dorsal plate L 815–1040, W 325–440; coxae III+IV L 190–220, W 55–70; genital field L 190–220, genital plate W 55–70; pedipalpal segments (P-1–5) L: 20–35, 210–265, 85–130, 150–190, 60–90; leg segments L: I-Leg-1–6—120–140, 125–190, 175–210, 250–285, 165–265, 150–200; II-Leg-1–6—110–125, 125–205, 235–290, 335–390, 300–375, 235–285; III-Leg-1–6—100–135, 125–220, 200–230, 235–300, 300–330, 250–280; IV-Leg-1–6—185–215, 185–220, 260–285, 435–470, 585–525, 420–535.

Deutonymph. See Hevers 1979.

Larva. See Hevers 1980.

Habitat. Lakes, ponds, reservoirs, running waters.

Hosts. Unionidae . Very numerous host species in different countries and continents ( Viets& Plate 1954; Hevers 1980; Wen & Zhu 1999; Wu et al. 2012; Edwards & Vidrine 2013). Hosts in Russia and Ukraine: Anodonta cygnea Linnaeus , A. anatina Linnaeus, Amuranodonta kijaensis Moskvicheva, Pseudoanodonta complanata Rossmaessler ( Saenko et al. 2010; Yanovich & Shevchuk 2012; Zhavoronkova & Pesnya 2013).

Distribution. Europe, Asia, North America ( Mitchell 1954; Viets 1956; Lundblad 1968; Viets 1978).

Figures

FIGURES 41 A – D. Unionicola ypsilophora, adults: A, dorsal plates of female; B, coxal plates of female; C, dorsal view of male; D, coxal plates of male. Scale bars = 200 Μm.

FIGURES 42 A – F. Unionicola ypsilophora, adults: A – B, genital field; C, pedipalp, lateral view; D, IV-Leg- 4 – 6; E, claw of leg I; F, claw of leg IV; A, C – D, male; B, E – F, female. Scale bars: A – C, E – F = 100 Μm, D = 200 Μm.