Ljania macilenta Koenike, 1908

Tuzovskij, Petr V., 2012, Water mites of the genus Ljania Thor, 1898 (Acari: Hydrachnidia: Aturidae) in Russia, Zootaxa 3249, pp. 1-17 : 3-8

Ljania macilenta Koenike, 1908

( Figs 1–15 )

Material examined: 7 males, 8 females and 6 deutonymphs, Russia, North Caucasus, Krasnodar Territory, Seversk District, Ubin River near settlement Ubinskaya, May–June 1976, leg. P.V. Tuzovskij.

Diagnosis. Adults: Idiosoma elongate (L/W ratio 1.28–1.30), with straight anterior margin, medial margins of Cx–IV separated, anteromedial margin of Cx–IV nearly twice as long as posteromedial margin (posterior to indentation), dorsoproximal and dorsodistal setae on P–3 nearly subequal in L and shorter than dorsal margin of segment, ventral setae on P–4 placed near middle of segment, leg claws with short external and long internal clawlets, genital field of male with 9–12 pairs of fine setae.

Morphology. Both sexes: Idiosoma with straight anterior margin between setae Vi. Dorsal shield elongate (L/ W ratio 1.30–1.42) Setae Si without glandularia, near distal end of this shield.

Anterior ends of Cx–I/II usually not reaching of idiosoma anterior edge ( Fig. 2 ); suture line between Cx–I/II and Cx–III/IV complete, suture line between Cx–II/III incomplete obliterated medially; medial margins of Cx–IV and posteromedial portions of Cx–III well separated, anteromedial portions of Cx–III fused to each other complete; anteromedial margin of Cx–IV 1.5–2.0 times as long as posteromedial margin. Chelicera ( Fig. 3 ) stocky, with large basal segment and moderately developed stylet, basal segment with rather large, obtuse dorsal hump.

Pedipalp ( Fig. 4 ) moderately slender: P–3 shorter than P–2, with 2 dorsoproximal and 2 dorsodistal setae nearly subequal in size, all these setae shorter than dorsal margin of segment; P–4 ventral setae distal to middle of segment.

Claws of all legs ( Figs 7–8 ) with external clawlet shorter than internal clawlet.

Male. Genital field with 9–12 fine setae on each side; all acetabula small, but anterior acetabulum slightly smaller than both posterior acetabula; distance between anterior acetabulum and both posterior acetabula considerably longer than maximum acetabulum diameter.

Measurements (n=7). L of idiosoma 425–470, W 335–365; L of dorsal shield 390–440, W 290–330; L of anteromedial portion of Cx– IV 48 –60; L of posteromedial portion 35–42; L of genital field 72–85, W 120–165; L of genital acetabula (ac. 1–3): 12–17, 18–21, 18–21; L of capitulum 66–85; L of cheliceral basal segment 66–72, L of cheliceral stylet 27–30; L of pedipalpal segments (P–1–5): 23–25, 36–42, 30–33, 51–55, 24–27; L of leg segments:

I–Leg–1–6: 30–35, 42–48, 54–60, 60–66, 65–72, 78–90; II–Leg–1–6: 27–30, 36–42, 42–48, 48–55, 55–65, 60–65; III–Leg–1–6: 30–35, 36–42, 39–48, 48–60, 55–72, 65–70; IV–Leg–1–6: 60–69, 60–66, 65–70, 85–95, 85– 95, 80–90.

Female. Genital plates free L/W ratio 1.20–1.25, ( Fig. 2 ).

Measurements (n=8). L of idiosoma 510–540, W 390–420; L of dorsal shield 470–500, W 335–360; L of anteromedial portion of Cx– IV 60 –72, L of posteromedial portion 48–50; L of genital plate 60–75, W 48–60; L of genital acetabula (ac. 1–3): 15–18, 20–24, 20–24; L of capitulum 78–86; L of cheliceral basal segment 68–72, L of cheliceral stylet 30–35; L of pedipalpal segments (P–1–5): 24–30, 48–50, 39–42, 60–69, 24–30; L of leg segments I-Leg–1–6: 30–35, 42–55, 60–69, 72–85, 80–90, 90–102; II–Leg–1–6: 30–35, 35–48, 42–45, 54–60, 60–72, 69– 75; III–Leg–1–6: 30–35, 45–50, 50–55, 65–70, 80–90, 70–85; IV–Leg–1–6: 65–73, 60–65, 78–85, 90–102, 100– 110, 85–95.

Deutonymph. Dorsal shield L/W ratio 1.05–1.27 ( Fig. 10 ).

Anterior ends of Cx–I not reaching anterior end of idiosoma; anteromedial margin of Cx–IV 2.0–2.5 times as long as posteromedial margin.

Pedipalp: Fig. 12 . Pedipalp moderately slender: P–1 short without seta; P–2 with straight ventral margin, with single dorsoproximal seta and 2 subequal dorsodistal setae; P–3 with slightly concave ventral margin, with 2 dorsodistal setae; P–4 relatively long, with straight ventral and convex dorsal margins, bearing a single short distolateral spine, 3-5 fine dorsolateral and 2 ventrodistal setae; P–5 with long proximal solenidion, 4 unequal distal spines and 2 fine setae.

Measurements (n=6). L of idiosoma 320–410, W 300–345; L of dorsal shield 255–285, width 210–250; L of anteromedial portion of Cx– IV 22–24, L of posteromedial portion 9–11; L of genital plate 35–42, W 25–26; L of genital acetabula (ac. 1–2): 10–14, 12–16; L of capitulum 55–65; L of cheliceral basal segment 63–65, L of cheliceral stylet 25–26; L of pedipalpal segments (P–1–5): 20–23, 38–42, 28–30, 45–51, 21–23; L of leg segments I– Leg–1–6: 22–29, 32–37, 44–48, 54–58, 57–60, 67–70; II–Leg–1–6: 22–26, 31–33, 32–35, 38–42, 45–48, 54–58; III–Leg–1–6: 22–29, 31–35, 35–38, 49–51, 57–62, 64–67; IV–Leg–1–6: 48–51, 44–48, 54–58, 70–72, 80–84, 75– 80.

Habitat. Rivers, streams, brooks.

Distribution. Europe ( Viets 1936; Viets 1956, 1978), Russia: North Caucasus, Krasnodar Territory (Tuzovskij 1978, 1990); Asia, Russia: Far East, Khabarovsk Territory, Jewish autonomous Province, Amur Province and Sakhalin Province ( Semenchenko 2005, 2010).

Figures

FIGURES 1 – 2. Ljania macilenta Koenike, female: 1 — dorsal view, 2 — ventral view. Scale bar, 1 – 2 = 100 μm.

FIGURES 3 – 8. Ljania macilenta Koenike, female: 3 - chelicera, 4 — pedipalp, lateral view, 5 — Leg I, 6 — leg IV, 7 — claw of leg I, 8 — claw of leg IV. Scale bars: 3 – 4 = 20 μm, 5 – 6 = 50 μm, 7 – 8 = 25 μm.

FIGURE 9. Ljania macilenta Koenike, male: 9 — ventral view. Scale bar: 9 = 100 μm.

FIGURES 10 – 11. Ljania macilenta Koenike, deutonymph: 10 — dorsal view, 11 — ventral view. Scale bar, 10 – 11 = 100 μm.

FIGURES 12 – 15. Ljania macilenta Koenike, deutonymph: 12 — pedipalp, 13 — leg I, 14 — leg IV, 15 — claw. Scale bars: 12 = 20 μm, 13 - 14 = 50 μm, 15 = 25 μm.