Lebertia (Pilolebertia) makarovae, 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 : 62-63

Lebertia (Pilolebertia) makarovae sp. n.

( Figs. 1–8 )

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

Material examined. Holotype: female, slide 9088, Europe, Arkhangelsk Region, Vaigach Island, Domashnee Lake , 65.369992 N, 47.569208 E, depth about 90 cm, substrates: stones, sand, 27.07.2004, leg. O. Makarova.

Diagnosis. Integument finely striated, coxal shield wider than long, ml of coxal plates I longer than suture line between coxal plates II, coxal shield embracing the genital field to about 5/6 with rounded posteromedial corners; genital field with three pairs of small subequal acetabula; P-2 ventral seta shorter than ventral margin of segment, P-3 mediodistal seta halfway between dorso- and ventrodistal setae, P-4 ventral sectors 1:1:1, mediodistal peg-like seta short, pointed; IV-Leg-6 with five to six short, thick ventral setae.

Description. Female. Integument soft and finely striated. Setae Fch ( Fig. 1 ) longer and thicker than other idiosomal setae. Trichobothria Fp, Oi and setae Pi not associated with glandularia ( Fig. 2 ), other idiosomal setae associated with glandularia ( Fig. 3 ). Coxal shield ( Fig. 4 ) wider than long (L/W ratio 0.82), medial length of coxal plates I longer than suture line between coxal plates II (ml Cx-I/Cx-2 ratio 1.9). 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 5/6 and forming nearly rounded posteromedial corners.

Genital field ( Figs. 4 , 6 ) with three pairs of small subequal acetabula, lying on elongated basal sclerites, flaps with 25–29 medial and two fine lateral setae each; pregenital sclerite with short posteromedian projection, postgenital sclerite much broader than anterior one. Excretory pore unsclerotised.

Pedipalp moderately long ( Fig. 5 ): P-1 short, with single dorsodistal setae; P-2 with three to four unequal dorsoproximal and two long subequal dorsodistal setae, ventral margin slightly concave, ventrodistal seta thick, shorter than ventral margin of segment inserted away from ventrodistal segment edge; P-3 comparatively short, ventral margin concave, mediodistal seta halfway between dorso- and ventrodistal setae, both dorsoproximal setae well-separated; P-4 thickened proximally and narrowed distally, ventral sectors about 1:1:1, two to three dorsodistal setae shifted to middle of segment, mediodistal peg-like seta thick and pointed.

Legs II–IV with swimming setae, their number as following: five to six on II-Leg-5 and IV-Leg-4, five on III-Leg-4, 7–11 on III-Leg-5, 10–11 on IV-Leg-5; IV-Leg-6 with five to six short spine-like ventral setae ( Fig. 7 ). Leg claws with short internal and comparatively long external clawlets, lamella moderately developed with slightly concave ventral margin ( Fig. 8 ).

Measurements (n = 1). Idiosoma L 1250; coxal shield L 875, W 1060; coxal plate I mL 235, coxal plate II mL 125, posterior margin of coxal plates II W 80; capitular bay L 275, W 135; genital bay 250, W 310; genital flap L 275, W 125, genital acetabula (ac-1–3) L 55, 55–60, 55; pedipalp segments (P-1–5) L: 42, 155, 120, 180, 45, P-4 medio-distal peg-like seta L 14–15; leg segments L: I-Leg-1–6: 100, 125, 160, 225, 225, 185; II-Leg-1–6: 100, 160, 185, 285, 310, 260; III-Leg-1–6: 110, 185, 250, 375, 410, 335; IV-Leg-1–6: 225, 225, 285, 435, 460, 375.

Male. Unknown.

Differential diagnosis. The new species is similar to Lebertia porosa Thor, 1900 and L. chaunensis Tuzovskij, 2011 . The adults of L. porosa are characterised by the following features: anterior two pairs of acetabula subequal in the shape and size and distinctly larger than the posterior pair; all acetabula located close to each other on each side ( Fig. 9 ). In contrast, in the female L. makarovae all acetabula small, subequal in the shape and size and distinctly separated on each side, Fig. 6 . Lebertia chaunensis differs in the integument with ribbed sculpture, setae Fch with a short proximal furca ( Tuzovskij 2011).

Etymology. The species is named after the collector, Dr. Olga Makarova.

Habitat. Lakes.

Distribution. Europe, Russia: Arkhangelsk Region.

Figures

Figs. 1–5. Lebertia makarovae sp. n., female: 1 — seta Fch; 2 — seta Oi; 3 — seta Oe; 4 — ventral view; 5 — pedipalp. Scale bars: 1–3, 5 = 100 μm; 4 = 200 μm Рис. 1–5. Lebertia makarovae sp. n., самка: 1 — щетинка Fch; 2 — щетинка Oi; 3 — щетинка Oe; 4 — вентраΛьная сторона; 5 — пеΔипаΛьпа. ШкаΛы: 1–3, 5 = 100 μm; 4 = 200 μm

Figs. 6–9. Lebertia females: 6–8 — Lebertia makarovae sp. n., 6 — genital field; 7 — IV- Leg-4–6; 8 — l eg claw; 9 — Lebertia porosa, genital field. Scale bars: 6, 9 = 100 μm, 7 = 200 μm, 8 = 50 μm Рис. 6–9. Lebertia самки: 6–8 — Lebertia makarovae sp. n., 6 — генитаΛьное поΛе; 7 — нога IV-4-6; 8 — коготок ног; 9 — Lebertia porosa, генитаΛьное поΛе. ШкаΛы: 6, 9 = 100 μm; 7 = 200 μm; 8 = 50 μm