Yasudatyla kurilensis Mikhaljova, 2015, sp. nov.

Yasudatyla kurilensis sp. nov.

Figs 1–11

Material examined. Holotype: 1 male (ZMUM: ρ2651), Russia, Kuriles, Kunashir Island, environs of cordon Alekhino, coniferous forest, litter, 6.VI 2011, leg. A. Matalin, I. Melnik. Paratypes: 1 male, 1 female (IBSS), 1 female (ZMUM: 1 f ρ2652), Russia, Kuriles, Kunashir Island, environs of cordon Andreevskii, Ulmus forest, litter, 23.V 2011, leg. A. Matalin, I. Melnik; 1 female (ZMUM: 1 f ρ2653), Russia, Kuriles, Kunashir Island, mouth of Ozernaya River, litter, 43°53´06´´ N, 145°27´44´´ E, 25.VII 2011, leg. K. Makarov; 1 male (IBSS), Russia, Kuriles, Shikotan Island, southern part, Tserkovnaya Bay, 25–30.V 2012, leg. Yu.N. Sundukov.

Diagnosis. Differs from congeners mainly in the structure of the anterior gonopod, with a caudal, thin, hookshaped process in the distal portion of the anterior coxite and by the form of the posterior coxite posterior flagellar branch and fimbriate branch at its base as well as by the structure of the posterior gonopod ventral, long, curved coxal process and a short process placed at its base on the front surface of the coxa, directed forward.

Description. Male. Length 10–11 mm, width 0.9–1.0 mm. Coloration in alcohol white, with a pattern of lightbrown marbled spots and bands on dorsum and upper portions of lateral sides. Posterior edge of metazonites dorsally with a transverse light-brown thin undulating band. Coloration more intense in anterior and posterior body parts. Head brown, its anterior portion lighter. Legs white, with brownish distal parts. Antennae brown. Eyes black.

Body with 30 segments. Head covered with sparse setae. Epicranial suture inconspicuous. 18–20 ocelli in a trapeziform eye patch. Antennae long and slender. Collum elliptical. Diplosegments subcylindrical, with metazonites swollen and laterally projecting. Metazonital setae slender, acute, short. Macrochaetae in a transverse row on segments 28–29, as an extended triangle on preceding segments. Macrochaetae on segments 1–3(4) longer than those on subsequent segments.

Legs 1 and 2 reduced in size, each with tarsal brushes and strong long setae on ventral surface of tibia and postfemur. Legs 3 (Fig. 1) and 4 (Fig. 2) slightly enlarged, each femur with distal, cylindrical knob mesally. Legs 5–7 approaching normal size. Starting from legs 3, walking legs with funnel-shaped tarsal papillae gradually missing toward end of body (tarsal papillae of midbody legs occupying 2/3 length of tarsus i.e. space near claw free from papillae; ultimate legs without tarsal papillae); claw at base (including leg pairs 1 and 2, 10 and 11) (Fig. 3) with small additional claw dorsally and a thin setiform claw ventrally. Additional dorsal and ventral claws gradually growing reduced towards posterior body end; at least claws of ultimate legs devoid of these claws. Legs 10 (Fig. 4) with coxal glands, in addition, each coxa with low finger-shaped process. Legs 11 without coxal glands and other modifications, of normal size.

Anterior gonopods as in figs 5–6. Anterior coxite (ac) subtriangular with slender elongate distal part, deep fossa laterally at base and thin hook-liked process (h) arising from caudal surface. Front flagellar branch (fb) smooth and long, about length of anterior coxite. Posterior coxite (pc) with blunt apex and dense cuticular spinules on posterior surface, about half length of anterior coxite. Posterior flagellar branch (pb) with thickened base and flagelliform distal part covered with cuticular fringe in the middle portion frontally. Subtriangular deeply fimbriate branch (b) with elongate distal part located at the base of pb.

Posterior gonopods (Figs 7–8, 11) each with two (long and short) processes of coxa; ventral long coxal process (lp) curved anterior, its apex with fovea; short process (sp) placed at base of long process on front surface of coxa, directed forward with sheaf of setae (Fig. 7). Posterior surface of posterior gonopod coxa without additional processes (Figs 8, 11). Prefemur without lobes; apical article ovoid, swollen.

Female. Length 10–11 mm, width 1.0 mm. Body with 30 segments. 18–20 ocelli. Nonsexual characters as in male. Vulvae as in Figs 9–10. These photos show vulvae of two different females.

Name. The specific epithet refers to the terra typica (Kurile Islands).