Unionicola markovensis Tuzovskij 1990

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.

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).