Lebertia (Septlebertia) boldyrbekensis, Tuzovskij, 2021

Tuzovskij, Petr V., 2021, Description of a new water mite species of the genus Lebertia Neuman, 1880 (Acari, Hydrachnidia: Lebertiidae) from Kazakhstan, Zootaxa 5082 (2), pp. 185-190 : 186-189

Lebertia (Septlebertia) boldyrbekensis sp. n.

( Figs 1–12 )

Material examined. Holotype: male, slide 9934, Asia , Kazakhstan, Turkestan Province , Tolibiysky District , Aksu-Zhabagly Nature Reserve, Boldyrbek stream, 42°15’19.4”N 70°25’48.9”E, 1745 м, depth 40 cm, substrates: large stones, mosses, white sand, 16.08.2019, leg. V. Stolbov . Paratype: 1 female with the same locality and data as holotype .

Diagnosis. Integument lineated; coxal shield nearly as long as wide, medial length of coxal plates I longer than suture line between coxal plates II, coxal shield embracing the genital field to about 3/4 with acute posteromedial corners; P-2 ventral margin straight, P-3 with seven to nine setae, three to four proximal and four to five distal (two dorsal and two to three ventral); legs without swimming setae, IV-Leg-6 ventral margin concave with four short ventral setae.

Description. Both sexes. Integument with short dorsal and postventral strips ( Fig. 1 ) Setae Fch ( Fig. 2 ) longer and thicker than other idiosomal setae. Coxal plates I fused to each other nearly completely, fragment of suture line present only in posterior part ( Fig. 3 ). Medial suture of coxal plates I a little longer than suture line between coxal plates II. Posterior margin of coxal plates II narrow. Coxal shield embracing the genital field to about ¾, with acute posteromedial corners. Genital field with three pairs of acetabula, posterior pair smaller than both anterior pairs of acetabula ( Figs 4–5 ). Excretory pore oval ( Fig. 6 ). Capitulum ( Fig.7 ) with short rostrum and equally convex ventral margin. Basal segment of chelicera large, with obtuse dorsal protrusion and nearly straight ventral margin; chela small sickle-shaped ( Fig. 8 ).

Pedipalp moderately long ( Fig. 9 ): P-1 short, with single dorsodistal setae; P-2 with three unequal dorsoproximal and two rather long subequal dorsodistal setae, ventral margin straight or slightly concave proximally, ventrodistal seta thick, long, inserted away from ventrodistal segment edge; P-3 slender, nearly as long as P-4, ventral margin straight, with three to four proximal setae and four to five distal setae (two dorsal and two to three medioventral),all ventrodistal setae close to each other; P-4 slender, with straight ventral margin, divided by seta insertions into three sectors 3:2:3, mediodistal peg-like seta pointed, its length about 2/5 of P-5. Legs without swimming setae, I-Leg-6 with straight subparallel dorsal and ventral margins ( Fig. 10 ), tarsi of legs II-IV slightly expanded distally, IV-Leg-6 ventral margin concave, with four short, thin setae ( Fig. 11 ). Leg claws with short interior and long exterior clawlets, lamella with slightly concave ventral margin ( Fig. 12 ).

Male. Coxal shield almost as long as wide (L/W ratio 1.01). Medial sutureof coxal plates I longer than suture line between coxal plates II (coxal plates I/coxal plates II mL ratio 1.36). Genital flaps elongate (L/W ratio 2.8), with about 40 medial and five to six lateral setae each ( Fig. 4 ). Anterior genital sclerite with nearly straight posterior margin.

Measurements (n=1). Idiosoma L 875; coxal shield L 660, W 650; coxal plate I mL 150, coxal plate II mL 135; capitular bay 200, genital bay 160; genital flap L 190, W 75, genital acetabula (ac-1-3) L 62, 62, 40; capitulum L 225; pedipalp segments (P–1–5) L: 42, 96, 102, 115, 33, P-4 medio-distal peg-like seta L 18; leg segments L: Leg-1–6: 60, 100, 125, 175, 180, 160; II–Leg-1–6: 85, 110, 125, 185, 225, 200; III–Leg-1–6: 85, 125, 140, 235, 260, 235; IV–Leg-1–6: 150, 150, 200, 285, 310, 260.

Female. Coxal shield slightly wider than long (L/W ratio 0.94). Medial sutureof coxal plates I longer than suture line between coxal plates II (coxal plates I/coxal plates II mL ratio 1.25). Genital flaps comparatively broad (L/W ratio 2.1), with 26-27 medial thin setae ( Fig. 5 ). Anterior genital sclerite relatively large with short posteromedian projection.

Measurements (n=1). Idiosoma L 1350; coxal shield 825, W 875; coxal plate I mL 185, coxal plate II mL 135; capitular bay 250, genital bay 225; genital flap L 260, W 125; genital acetabula (ac-1-3) L 87, 75, 50; cheliceral segments L: base 350, chela 75; pedipalp segments (P–1–5) L: 48, 132, 145, 150, 40, P-4 medio-distal peg-like seta L 24; leg segments L: Leg-1–6: 85, 125, 150, 225, 235, 200; II–Leg-1–6: 85, 150, 175, 275, 300, 250; III–Leg-1–6: 85, 125, 140, 235, 260, 235; IV–Leg-1–6: 235, 200, 260, 375, 400, 325.

Differential diagnosis. The new species is similar to Lebertia dmitrii Semenchenko & Tuzovskij , from which it is distinguishable by the structure of appendages. The adults of L.dmitrii are characterized by the following features: P-2 ventral margin concave, P-3 with three distal setae; I-IV-Leg-6 with straight ventral margin ( Semenchenko & Tuzovskij 2010). In contrast, in adults L. boldyrbekensis sp. n. P-2 ventral margin straight, P-3 with four to five distal setae, IV-Leg-6 with concave ventral margin.

L. imamurai is similar to L. convergella in the integument structure, as well as shape of coxal shield and legs IV, but differs in the shape and setation of the pedipalps: in L. convergella , P-3 has 8-9 setae, and the P-4 ventral margin is divided by seta insertions into sectors 2:2:3 ( Tuzovskij 2004); while in L. imamurai the P-3 bears7 setae and the P-4 ventral margin is divided by seta insertions into sectors 4:2:1 ( Imamura 1954).

Etymology. The species epithet “ boldyrbekensis ” is derived from the name of the stream (Boldyrbek) where it was collected.

Habitat. Running waters.

Distribution. Asia, Kazakhstan: Turkestan Province.

Figures

FIGURES 1–8. Lebertia boldyrbekensis sp. n., adults: 1, fragment of integument; 2, seta Fch; 3, coxal shield and genital field;4, genital field; 5, right half of genital field; 6, excretory pore; 7, capitulum, lateral view; 8, chelicera; 1-4, 6-8, male, 5, female. Scale bars: 1-2, 4-5, 7-8 = 100 μm, 3 =200 μm, 6 = 50μm.

FIGURES 9–12. Lebertia boldyrbekensis sp.n., male: 9, pedipalp, 10, I-Leg-4-6; 11, IV-Leg-4-6; 12, leg claw. Scale bars: 9, 12 = 50 μm, 10-11 = 50 μm.