Lebertia (Mixolebertia) prokini, Tuzovskij, 2022

Tuzovskij, Petr V., 2022, Two new water mite species of the genus Lebertia Neuman, 1880 (Acari, Hydrachnidae: Lebertiidae) from northern lakes of Russia, Amurian Zoological Journal XIV (1), pp. 61-65 : 63-65

Lebertia (Mixolebertia) prokini sp. n.

( Figs. 10–18 )

http://zoobank.org/References/ 7D957D63-A03B-41E1-A567-5CEB2AACA492

Material examined. Holotype: male, slide 9945, Asia , Russia, Chukotka, Anadyr District, Elgygytgyn Lake , littoral zone, 67.489177 N, 172.087.142 E, bottom: stones, gravel, 6.08.2020, leg. A. Prokin.

Diagnosis. Integument finely striated, coxal shield slightly wider than long, ml of coxal plates I longer than suture line between coxal plates II, coxal shield embracing the genital field to about 3/4; genital field with three pairs of relatively large unequal acetabula; P-2 ventral seta and ventral margin of segment subequal in length, P-3 with two mediodistal setae located close to dorsodistal seta, P-4 ventral sectors 1:1:2, mediodistal peg-like seta comparatively large; IV-Leg-6 with five to six short, thick ventral setae.

Description. Male. Integument finely striated. Setae Fch ( Fig. 10 ) long, trichobothria Fp, Oi and setae Pi not associated with glandularia ( Fig. 11 ) and other idiosomal setae short and thin ( Fig. 12 ). Coxal shield ( Fig. 13 ) wider than long (L/W ratio 0.85), ml of coxal plates I slightly longer than suture line between coxal plates II (ml Cx-I/Cx-2 ratio 1.05). Coxal plates I fused to each other nearly completely, fragment of suture line present only in their posterior portion. Capitular bay deep U-shaped, genital bay comparatively short and a little wider than long. Posterior margin of coxal plates II rather broad. Coxal shield embracing the genital field to about 3/4 with rounded posteromedial corners.

Pedipalp moderately long ( Fig. 14 ): P-1 short, with single dorsodistal setae; P-2 with three dorsoproximal and two long subequal dorsodistal setae, ventral margin slightly concave, ventrodistal seta long, thickened basally, inserted away from ventrodistal segment edge; P-3 with four distal setae, two mediodistal setae located close to dorsodistal seta, P-4 ventral sectors 1:1:2, mediodistal peg-like seta comparatively large, two to three fine dorsal setae located near middle of segment.

Genital field ( Fig. 15 ) with three pairs of rather large unequal acetabula, first two pairs large than posterior one; flaps with 35–40 medial and three lateral fine setae each; pregenital sclerite without posterior projection. Basal segment of chelicera slender, thickened distally, chela small, sickle-shaped ( Fig. 16 ). Excretory pore unsclerotised.

Legs without swimming setae. IV-Leg-6 with six short, thick ventral setae ( Fig. 17 ). Leg claws with short internal and comparatively long external clawlets, lamella moderately developed with straight ventral margin ( Fig. 18 ).

Measurements (n = 1). Idiosoma L 1100 coxal shield L 850, W 875; coxal plate I mL 225, coxal plate II mL 215, posterior margin of coxal plate II W 85; capitular bay L 250; genital bay 160; genital flap L 235, W 125, genital acetabula (ac-1–3) L 65–75, 70–72, 50–55; pedipalp segments (P-1–5) L: 55, 150, 130, 165, 50, P-4 medio-distal peg-like seta L 16– 19; leg segments L: I-Leg-1–6: 100, 135, 160, 210, 250, 185; II-Leg-1–6: 100, 150, 175, 250, 310, 275; III-Leg-1–6: 125, 160, 185, 310, 375, 310; IV-Leg-1–6: 225, 200, 300, 410, 425, 350.

Female. Unknown.

Differential diagnosis. The present species is similar to Lebertia mamolinensis Tuzovskij, 1982 in the structure of the pedipalps. The adults of L. mamolinensis are characterised by the following features: the integument with irregular rugose sculpturing, Fig. 19; coxal shield embracing the genital field to about 2/3; P-2 ventrodistal seta shorter than ventral margin of segment, P-4 ventral sectors 1:1:1, Fig. 20; IV-Leg-6 with two to three short, thick ventral setae ( Tuzovskij 1982). In contrast, in male L. prokini sp. n. the integument smooth; coxal shield embracing the genital field to about ¾, Fig. 13 ; P-2 ventrodistal seta longer than ventral margin of segment, P-4 ventral sectors 1:1:2, Fig. 14 ; IV-Leg-6 with five to six short, thick ventral setae ( Fig. 17 ).

Etymology. The species is named after the collector, Dr. Alexandr Prokin.

Habitat. Lakes.

Distribution. Asia, Russia: Chukotka.

Figures

Figs. 10–14. Lebertia prokini sp. n., male: 10 — setaFch; 11 — seta Oi; 12 — seta Oe; 13 — ventral view; 14 — pedipalp, lateral view. Scale bars: 10– 13 = 100 μm; 14 = 50 μm Рис. 10-14. Lebertia prokini sp. n., самец: 10 — щетинка Fch; 11 — щетинка Oi; 12 — щетинка Oe; 13 — вентраΛьная сторона; 14 — пеΔипаΛьпа, боковая сторона. ШкаΛы: 10–13 = 100 μm; 14 = 50 μm

Figs. 15–18. Lebertia prokini sp. n., male: 15 — genital field, right side; 16 — chelicera; 17 — IV- Leg-6; 18 — leg claw. Lebertia porosa, male: 19 — fragment of integument; 20 — pedipalp. Scale bars: 15–17 = 100 μm, 18 = 50 μm Рис. 15–18. Lebertia prokini sp. n., самец: 15 — генитаΛьноепоΛе, правая сторона;16 — хеΛицера; 17 — Λапка ноги IV; 18 — коготок ног. Lebertia porosa, самец: 19 — фрагмент покрова; 20 — пеΔипаΛьпа. ШкаΛы: 15–17 = 100 μm, 18 = 50 μm