Rilaena kaschkataschica Snegovaya, 2025

Snegovaya, Nataly Y. & Makarova, Olga L., 2025, New data on harvestmen (Arachnida, Opiliones) of Caucasian glaciers, with descriptions of three new species, Zootaxa 5653 (1), pp. 123-132 : 126-128

Rilaena kaschkataschica Snegovaya sp. nov.

( Fig. 2 )

Material. Holotype: 1♂ ( ZMMU), Republic of Kabardino-Balkaria, Adyl-Su River valley, Kashkatash Glacier foreland, 153 years old site [Line IX], 2277 m a.s.l., 43.217998° N, 42.685711° E, mature pine forest with Hedysarum sp. and mosses, in barber pitfall, 19.07.2023, leg. O.L. Makarova ; Paratypes: 2♂♂, 4♀♀, 5 juv. ( RCNS), same place with Holotype; 1♀ ( ZMMU), same place, 91 years old site [Line VI], 2385 m a.s.l., 43.213850° N, 42.686481° E, sloping birch forest with forb grasses, 15− 22.07.2023, leg. O.L. Makarova.

Description. The body is square shaped, with a pointed back. The body color is sandy with dark brown spots and a distinct dark brown saddle-shaped pattern ( Fig. 2A ). Body length 4.0 mm long, 2.4 mm width. The eye mound is slightly trapezoidal with 10 small denticles ( Fig. 2B ). Leg Fe I fusiform, all leg Fe with transverse rows of denticles ( Fig. 2C ). Lengths of leg segments: I: 2.5+1.0+2.6+3.0+5.0 = 14.1; II: 5.5+1.5+4.6+5.4+ 6.7 =23.7; III: 3.7+1.2+3.0+4.0+5.0= 16.9; IV: 5.0+1.4+3.6+6.2+7.2 =23.4. Fe pedipalps dorsally and ventrally with black-tipped denticles, dorsally also with large teeth. Pa and Ti with apophyses completely covered with setae, Ta with setae, laterally with microdenticles ( Figs. 2D–E ). Pedipalp lengths 1.5+1.1+1.0+1.8 =5.4. Male chelicerae dorsally with several denticles, the other parts with setae ( Figs. 2F–G ). Cheliceral basal segment length 1.5, distal segment 1.6. The penis with a wide base, narrows towards the middle and then widens closer to the glans, wings not wide ( Figs. 2I–K ).

The female differs from the male in larger body sizes and a rounded body shape ( Fig. 2L ). The female has wider and rounded apophyses on the pedipalp, while the male has pointed ones ( Figs.2M–N ).The male has larger chelicerae. Female body length 7.0, wide 4.0. Pedipalp lengths 1.5+0.8+0.8+1.8 =4.9. Cheliceral basal segment length 1.3, distal segment 1.8 ( Figs. 2 O-P). Lengths of leg segments: I: 3.0+1.0+2.5+3.0+4.4 =13.9; II: 4.0+1.2+4.0+5.0+8.4 =22.6; III: 2.6+1.0+2.2+4.0+4.2 =14.0; IV: 4.2+1.4+3.5+5.0+5.6 =19.7.

Diagnosis. A new species most closely related to the Rilaena caucasica Snegovaya et Tchemeris, 2016 , but different from it the structure of the penis— R. caucasica has more rounded and wider penis wings ( Figs. 2 I–K ; Snegovaya & Tchemeris, 2016: Figs. 1 M–O ).

Etymology. The species is named after the Kashkatash Glacier in Kabardino-Balkaria ( Russia).

Distribution. Known only from the type locality in Republic of Kabardino-Balkaria ( Russia).

Figures

FIGURE 1. Rilaena kabardinibalkarica sp. nov. A. male body, habitus dorsal; B. male eye tubercle, dorsal; C. male femur I, dorsal; D, E. male left pedipalp (D—lateral, E—mesal); F, G. male left chelicera (F—lateral, G—mesal); H, I. penis (H— dorsal, I—lateral); J, K. close-up of penis glans (J—dorsal, K—lateral); L. female body, habitus dorsal; M, N. female right pedipalp (M—lateral, N—mesal); O, P. female right chelicera (O—lateral, P—mesal). Scale: A, C, L 1.0 mm; D–I, M–P 0.5 mm; J–K 0.1 mm.

FIGURE 2. Rilaena kaschkataschica sp. nov. A. male body, habitus dorsal; B. male eye tubercle, dorsal; C. male femur I, dorsal; D, E. male right pedipalp (D—lateral, E—mesal); F, G. male right chelicera (F—lateral, G—mesal); H, I.—penis (H—dorsal, I—lateral); J, K. close-up of penis glans (J—dorsal, K—lateral), L. female body, habitus dorsal; M, N. female right pedipalp (M—lateral, N—mesal); O, P. female right chelicera (O—lateral, P—mesal). Scale: A, L 1.0 mm; C–I, M–P 0.5 mm; J–K 0.1 mm.