Lebertia (Mixolebertia) sokolowi, Tuzovskij, Petr V. & Semenchenko, Ksenia A., 2009

Tuzovskij, Petr V. & Semenchenko, Ksenia A., 2009, New water mites species (Acariformes: Hydrachnidia) from the Far East of Russia, Zootaxa 2241, pp. 1-21 : 10-14

Genus Lebertia Neuman, 1880

Lebertia (Mixolebertia) sokolowi sp. n. ( Figs. 24–40 )

Type series. Holotype male (236-kas– IBSS), Russia, Khabarovsk Territory, Ul’chsky District, the Amur River basin, the Sushchevsky Kluch River, 12.10.2006, leg. N.M. Yavorskaya. Paratypes: 5 males and 1 female (9523–male, 9524 – 2 males, 9525 – male, 9526 – male and female, IBIW) same locality and date as holotype; 1 male (237-kas– IBSS), 3 females (238-240-kas– IBSS), 3 deutonymphs (241-243-kas– IBSS), Russia, Khabarovsk Territory, Ul’chsky District, the Amur River basin, the Kadi River, 13.10.2006, leg. N.M. Yavorskaya.

Description. Both sexes. Body oval, its length slightly exceeding width. Integument soft without sclerotized muscle attachment plates dorsally and ventrocaudally, with fine strips or wrinkles. The number and position of idiosomal setae and lyriform organs typical for the genus Lebertia . Setae Fch ( Fig. 24 ) longer and thicker than other idiosomal setae, with short shoot near their bases. Trichobothria Fp and Oi ( Fig. 25 ) without glandularia, other dorsal setae associated with glandularia ( Fig. 26 ). Eye lenses in capsules, occupying anterolateral position on each side, anterior lens larger than posterior one.

Coxae of legs ( Fig. 27 ) occupying more than half of idiosoma length, their total length slightly shorter than its width. Suture between coxae I distinct only in posterior part. Posteromedial part of coxae II narrow with slightly developed apodemes, medial suture line distinct and slightly shorter than the medial suture line of coxae I. Lateral margins of coxae III three to four times as long as their medial part in the place where the suture between coxae III+IV ends. Posterior coxae (IV) broader in the medial and narrower in the lateral parts.

Medial and posterior margins of coxae IV join at acute angle. Anterior ends of coxal plates I ( Fig. 28 ) bearing setae and glandularia Pe. Apexes of posteromedial angles of these coxae right or acute. Coxae of all legs have an alveolate pattern. Genital flaps relatively large, extending by one third or one fourth beyond posteromedial angles of fourth coxae, their width gradually increasing posteriorly. Anterior two pairs of acetabula approximately subequal in size and slightly longer than the posterior pair. Total length of acetabula smaller than the length of flaps. Excretory pore ( Fig. 29 ) elongated, surrounded by narrow sclerotized ring, it opens near posterior body end.

Basal segment of chelicera ( Fig. 32 ) very long, its posterior and medial parts thin and anteriorly broader. Cheliceral stylet small, with knee-like bend, its terminal part pointed with two rows of fine dorsal teeth.

Trochanter of pedipalp ( Fig. 33 ) short, with one dorsodistal seta. Pedipalpal femur large and stocky, with slightly concave ventral and convex dorsal margin; ventrodistal seta long and plumose in distal half, but shorter than ventral margin of femur. The base of ventrodistal seta at a distance of one or two its diameters from ventrodistal end of femur. Femur dorsally with five setae, three short proximal and two relatively long distal. Pedipalpal genu usually with three proximal (occasionally with two proximal setae) and three distal setae; proximal lateral seta longer than both dorsoproximal setae; medial distal seta close to the dorsodistal seta and longer than both distal setae. Ventral margin of pedipalpal tibia slightly concave, the dorsal margin slightly convex. The bases of two ventral setae divided tibia into three unequal parts; first seta located in proximal half of tibia, second seta near middle of segment. Distolateral spine on tibia thick with acute apex, its length one half of tarsus. Some dorsal thin setae (two or three) near the middle of tibia.

Posterior legs slender, without swimming setae. Tarsi of legs II–IV slightly expanded distally ( Fig. 34 ). Terminal segments of anterior pair of legs provided by thin setae, terminal segments of posterior legs armed by spine-like setae. Claws ( Fig. 35 ) with well developed plate and two clawlets: short interior and long exterior, both clawlets with acute apex. Ventral margin of claw blade concave.

Male. Genital flaps ( Fig. 30 ) with numerous median setae and 6–8 lateral ones.

Measurements (n=5). Length of body 815–1125; length of seta Fch 85–90; length of coxal shield 697– 765, width 714–775; length of median suture of coxal plates I 185–200, length of median suture of coxal plates II 175–190; length of capitular bay 178–195, length of genital bay 150–200; length of genital flaps 160–182, width 62–75; length of genital acetabula (Ac. 1–3): 53–63, 48–52, 32–38; length of capitulum 225– 250; length of basal segment of chelicera 250–265, length of cheliceral stylet 50; length of pedipalpal segments (P-1–5): 30–33, 92–112, 94–114, 74–120, 28–35; length of leg segments: I-L- 1–6 – 75 –90, 100– 125, 110–125, 185–200, 195–205, 175–200; II-L- 1–6 – 85 –110, 105–125, 135–150, 225–240, 250–265, 235– 250; III-L- 1–6 – 85 –100, 120–140,135–150, 224–250, 260–290, 250–290; IV-L-1–6 – 160–175, 140–165, 191–220, 264–295, 290–330, 260–290.

Female. Similar to the male but larger. Genital flaps with 16–17 median and 1–2 lateral setae ( Fig. 31 ).

Measurements (n=4). Length of body 918–1125; length of seta Fch 90–100; length of coxal shield 735– 833, width 697–816; length of median suture of coxal plates I 185–244, length of median suture of coxal plates II 170–191; length of capitular bay 210–218, length of genital bay 165–175; length of genital flaps 198–211, width 79–100; length of genital acetabula (Ac. 1–3): 62–70, 53–60, 40–51; length of capitulum 211–260; length of basal segment of chelicera 270–284, length of cheliceral stylet 50–60; length of pedipalpal segments (P-1–5): 40–42, 118–132, 120–134, 132–145, 35–42; length of leg segments: I-L- 1–6 – 60 –90, 118– 125, 130–145, 185–230, 210–257, 185–237; II-L- 1–6 – 80 –100, 125–132, 132–152, 231–251, 257–284, 235– 264; III-L- 1–6 – 90 –100, 130–165, 158–172, 257–277, 300–323, 260–290; IV-L-1–6 – 184–198, 158–165, 224–234, 300–317, 325–343, 284–310.

Deutonymph. Dorsal side and structure of integument similar to that of adults. Setae Fch ( Fig. 36 ) as in adults, longer and thicker than other idiosomal setae, with short shoot near their bases. Coxae of legs occupying more than half of ventral side, their total length almost subequal to its width ( Fig. 37 ). Posteromedial part of coxae II narrow with slightly developed apodemes, medial suture line distinctly shorter than the medial suture line of coxae I. Medial and posterior margins of coxae IV join at almost straight angle. Genital flaps narrow free, bearing 3–4 setae. Genital acetabula almost subequal in size. Pregenital sclerite free. Excretory pore surrounded by narrow sclerotized ring.

Trochanter of pedipalp without setae ( Fig. 38 ). Pedipalpal femur with slightly concave ventral and convex dorsal margin; without ventral setae, bearing three setae on dorsal surface, two distal setae longer than proximal one. Pedipalpal genu with two long dorsodistal setae, exceeding end of next segment. Ventral margin of pedipalpal tibia straight, the dorsal margin slightly convex. The bases of two ventral setae divided tibia into three unequal parts (approximately as 1:2:2). Distolateral spine on tibia with acute apex, its length one half of tarsus.

Posterior legs slender, without swimming setae. Tarsi of legs II–IV slightly expanded distally ( Fig. 39 ). Claws ( Fig. 40 ) with well developed plate and two clawlets: short interior and long exterior. Ventral margin of claw blade concave.

Measurements (n=3). Length of body 500–554; length of seta Fch 50–60; length of coxal shield 356–370, width 363–382; length of median suture of coxal plates I 112–119, length of median suture of coxal plates II 81 –86; length of capitular bay 105–114, length of genital bay 44–51; length of genital flaps 54–71, width 64– 74; length of genital acetabula (Ac. 1–3): 20–21, 22–24; length of capitulum 145–160; length of basal segment of chelicera 135–143, length of cheliceral stylet 32–34; length of pedipalpal segments (P-1–5): 15– 18, 66–68, 58–61, 76–78, 23–24; length of leg segments: I-L- 1–6 – 32 –34, 51–60, 65–98, 92–129, 105–110, 115–119; II-L- 1–6 – 50 –55, 61–68, 71–75, 110–122, 132–143, 136–139; III-L- 1–6 – 51 –60, 68–92, 75–85, 124–129, 150–156, 156–160; IV-L- 1–6 – 92 –95, 73–75,104–108, 150–160, 166–177, 163–173.

Differential diagnosis. The new species belongs to the subgenus Mixolebertia Thor (Gerecke 2009) . The combination of the following characters separate Lebertia sokolowi sp. n. from all other species of the subgenus Mixolebertia : integument with wrinkles or strips, seta Fch with short ramus near its base, pedipalpal genu and tibia almost subequal in length, some dorsal thin setae (two or three) are near the middle of pedipalpal tibia, ventral setae on this segment subequal, legs without swimming setae.

Etymology. The species is named after Professor Ivan Ivanovich Sokolow in appreciation of his studies on water mites of the Russian Far East.

Habitat. Running waters.

Distribution. Khabarovsk Territory, Far East of Russia.

Figures

FIGURES 24 – 31. Lebertia sokolowi sp. n., male (24 – 30) and female (31): 24, seta Fch; 25, seta Oi; 26, seta Oe; 27, coxal shield and genital field; 28, anterior end of coxa I; 29, excretory pore; 30, genital field of male; 31, genital field of female. Scale bars = 100 μm for Fig. 27, 30 – 31; 50 μm for Figs. 24 – 26, 28 – 29.

FIGURES 32 – 35. Lebertia sokolowi sp. n., male: 32, chelicera; 33, pedipalp, medial view; 34, genu, tibia and tarsus of leg IV; 35, claw. Scale bars = 100 μm for Fig. 34; 50 μm for Figs. 32 – 33, 35.

FIGURES 36 – 40. Lebertia sokolowi sp. n., deutonymph: 36, seta Fch; 37, coxal shield and genital organ; 38, pedipalp, medial view; 39, genu, tibia and tarsus of leg IV; 40, claw. Scale bars = 100 μm for Figs. 37, 39; 25 μm for Figs. 36, 38, 40.