Sibiriulus aktashensis, Mikhaljova, Elena V., Nefediev, Pavel S., Nefedieva, Julia S., Sakhnevich, Miroslava B. & Dyachkov, Yuri V., 2014

Mikhaljova, Elena V., Nefediev, Pavel S., Nefedieva, Julia S., Sakhnevich, Miroslava B. & Dyachkov, Yuri V., 2014, Review of the millipede genus Sibiriulus Gulička, 1972, with descriptions of three new species from Altai, Siberia, Russia (Diplopoda, Julida, Julidae), Zootaxa 3866 (1) : -

Sibiriulus aktashensis sp. nov. Mikhaljova, Nefediev & Nefedieva

Figs 23–29 , 39 .

Material examined. Holotype: 1 male ( IBSS), Russia, Siberia, Republic of Altai, Ulagan District, near Aktash village, Mt. Sardyma, 50°20´02´´ N, 87°34´46´´ E, Larix sibirica forest with Pinus sibirica , motley grass vegetation, 1790 m a.s.l., 5 August 2006, leg. P.S. Nefediev and J.S. Nefedieva. Paratypes: 1 male ( IBSS), Russia, Siberia, Republic of Altai, Choya District, environs of Mt. Baltyrgan, chern dark coniferous taiga, 1700 m a.s.l., 3 August 2001, leg. N.V. Levina; 4 males, 1 female, 5 juveniles (ASU), 1 female ( ZMUM), Russia, Siberia, Republic of Altai, Ulagan District, ca. 20 air-km NW of Aktash, Lake Taldukol, 50°26´30´´ N, 87°32´09´´ E, Betula rotundifolia , motley grass vegetation, green mosses, 1832 m a.s.l., 19 July 2006; 1 male ( ZMUM), 2 males, 1 female without front part of body, 1 juvenile ( IBSS), 2 males (ASU), together with holotype, 5 August 2006; 1 male, 1 female (ASU), Russia, Siberia, Republic of Altai, Ulagan District, ca. 20 air-km NW of Aktash, N part of Lake Sorulukol, 50°28´34´´ N, 87°31´25´´ E, Pinus sibirica forest with Larix sibirica , short grass vegetation, green mosses, 2000 m a.s.l., 7 August 2007; 1 male (ASU), Russia, Siberia, Republic of Altai, Ulagan District, ca. 20 airkm NW of Aktash, N part of Lake Sorulukol, 50°27´44´´ N, 87°30´24´´ E, Betula rotundifolia , Salix glauca , Pentaphylloides fruticosa , motley grass vegetation, green mosses, 1817 m a.s.l., 9 August 2007; all leg. P.S. Nefediev and J.S. Nefedieva.

Material re-examined (specimen published by Mikhaljova & Nefediev 2003). 1 male ( ZMUM), Russia, Siberia, Central Altai, Aigulakskii Mt. Range, NW slope, middle flow of Belgebash River, pebble, 1700 m a.s.l., 2 July 2000, leg. A.V. Matalin.

Diagnosis. This species differs from congeners mainly by the structure of the gonopod opisthomere of which lateral side with relief projection in the form of hook bent forward, combined with the gonopod mesomere distal part somewhat narrowed.

Description. Male. Length about 13–15 mm, vertical diameter 0.8–0.9 mm, with 40(–2) [2 specimens], 41(–2) [4 specimens], 42(–2) [3 specimens], 43(–2) [1 specimen], 44(–2) [2 specimens], body segments, excluding telson. 2 males have been broken, so it is impossible to count the number of their body segments. Coloration brown with reddish tinge; dark brown round spot on each side of prozonite ring closer to paler venter. Each metazonite with dark brown transverse band along its front edge. Anterior portion of head brown or marbled brown, with two pale brown spots between antenna bases, vertex dark brown, occipital part marbled brown. Collum with frontal transverse dark brown band, marbled brown field occupying its dorsal and lateral portions, and hind, thin, transverse dark brown band thickened to axial line on dorsum. Legs pale brown to yellowish. Antennae dark brown.

Each eye patches composed of 24–26 ocelli on right side, 22–27 ocelli on left side of head. Supralabral setae 2+2, 3+2, labral ones 7+7, 7+8, 8+8, 8+9, 10+8. Antennae medium-sized, in situ reaching to segment 4. Length ratios of antennomeres 2–7 as 4.5:3.4:2.9:3.9:2.2:1, width ratios as 1.2:1.2:1.2:1.7:1.6:1, respectively. Distodorsal corolla of antennomeres 5 and 6 each with not less than 5 and not less than 6 sensory bacilli, respectively. Gnathochilarium as typical of the genus. Four setae on each lamella lingualis arranged longitudinally: first seta closer to tip, second seta - in medial portion and the latter two closer to promentum or all setae arranged at regular intervals.

Collum with very small striations laterally; prozonital surface of segment 7 ventrally delicately striate. 7–9 striae on metazonital surface between dorsal midline and ozopore. Short caudal projection of telson epiproct subcylindrical, its tiny claw-shaped process directed caudad and somewhat ventrad. Preanal ring covered with sparse relatively long setae. Anal valves densely setose.

Starting from leg pair 2, both tibiae and postfemora of walking legs with longitudinal sole pads, only several posteriormost legs without sole pads. Claw as typical of the genus. Leg pair 1 ( Fig. 23 ) and leg pair 2 ( Fig. 24 ) as typical of the genus. Penes subtriangularly notched at tip.

Gonopods as in Figs 25–29 . Opistho- and promere subequal in height but somewhat lower as compared with mesomere. Flattened promere ( Fig. 26 ) with oval apex, its caudal surface covered by papillae nearly throughout. Flagellum medium length, filiform distally. Mesomere ( Fig. 27–29 ) slightly bent caudad; its front surface as plate, densely papillate with a longitudinal lowering along near middle. Distal part of mesomere somewhat narrowed, with an apical fovea of which front edge roundly outcurved. Opisthomere distally with convex at obtuse angle caudal surface and with short pointed subapical process (a) (? phylacum) mesally. Interior parabasal spine (s) welldeveloped. Solenomere laterally with relief projection (h) in the form of hook, bent forward ( Fig. 27 ). Membranous velum (v) narrow with a blunt tip.

Female. Length 16–17 mm, vertical diameter 1.1 mm, with 43(–2), 43(–3), 44(–2) body segments, excluding telson. 1 female devoid of the front part of body, so it is impossible to count the number its body segments. Ocelli 23–27 on right side, 26–27 on left side of head. Labral setae 4+7, 7+7, 8+8. Collum without striae. Other nonsexual characters as in male.

Vulva. Operculum with subtriangular or rounded apical incision. Lateral longitudinal row of setae on operculum with 4–6 setae and mesal one with 2–5 setae; 2 apical setae are the longest. 14–16 setae on posterior bursal median sclerite; 7–11 setae on lateral and mesal sclerites of the bursa together. Bursal setae gradually elongated to vulva apex.

Etymology. The specific epithet refers to the locus typicus (environs of Aktash village).

Remarks. Restudy of a male from the Central Altai, Ulagan District, Aigulakskii Mt. Range (it is still on loan at IBSS), which was determined as Sibiriulus multinicus (see Mikhaljova & Nefediev 2003), shows that the male belongs to Sibiriulus aktashensis sp. nov.

Three females from the Central Altai, Ongudai District, Kyzylart Mt. Range which were also determined as Sibiriulus multinicus (see Mikhaljova & Nefediev 2003) require reexamination, taking into consideration the male specimens from an alpine meadow at 2,100-2,300 m a.s.l. within this territory. However, we assume that they belong to Sibiriulus aktashensis sp. nov., taking into account the geographical evidence.

Figures

FIGURES 23 – 26. Sibiriulus aktashensis sp. nov., male. 23, leg pair 1 (front view); 24, leg pair 2 and penes (caudal view); 25, gonopods (mesal view); 26, gonopod promere (caudal view); a, apical process of gonopod opisthomere; s, interior parabasal spine of gonopod opisthomere; v, velum.

FIGURES 27 – 29. Sibiriulus aktashensis sp. nov., male. 27, gonopods (lateral view); 28, gonopods (mesal view); 29, gonopod mesomere (front view); h, hook-shaped relief projection of gonopod solenomere. Scales in mm.

FIGURES 38 – 40. Sibiriulus baigazanensis sp. nov., male holotype (38); Sibiriulus aktashensis sp. nov., male paratype (39); Sibiriulus latisupremus sp. nov., male paratype (40). Habitus in lateral view. Photographed not to scale.