Sibiriulus baigazanensis Mikhaljova, Nefediev, Nefedieva, Sakhnevich & Dyachkov, 2014, sp. nov.

Sibiriulus baigazanensis sp. nov. Mikhaljova, Nefediev & Nefedieva

Figs 15–22, 38.

Material examined. Holotype: 1 male (IBSS), Russia, Siberia, Republic of Altai, Turochak District, Altai State Nature Biosphere Reserve, near cordon Baigazan, 51°45´31,6´´ N, 87°25´39,1´´ E, 448 m a.s.l., Padus avium, Salix caprea and Betula, 3 October 2013, leg. M.B. Sakhnevich. Paratype: 3 females (ASU), Russia, Siberia, Republic of Altai, Turochak District, Altai State Nature Biosphere Reserve, near cordon Baigazan, 51°45´34,9´´ N, 87°25´55,9´´ E, 460 m a.s.l., Padus avium and Sorbus sibirica, 30 September 2013; 1 male (ASU), Russia, Siberia, Republic of Altai, Turochak District, Altai State Nature Biosphere Reserve, near cordon Baigazan, 51°45´35´´ N, 87°26´02,3´´ E, 482 m a.s.l., Salix caprea, 30 September 2013; 2 females (ASU), Russia, Siberia, Republic of Altai, Turochak District, Altai State Nature Biosphere Reserve, near cordon Baigazan, 51°45´32,1´´ N, 87°25´54,8´´ E, 454 m a.s.l., Padus avium, 1 October 2013; 1 male, 4 females (ASU), Russia, Siberia, Republic of Altai, Turochak District, Altai State Nature Biosphere Reserve, near cordon Baigazan, 51°45´34,1´´ N, 87°26´03,6´´ E, 490 m a.s.l., Padus avium, 1 October 2013; 1 male, 1 female (ZMUM), 2 females, 1 juvenile (subadult female) (ASU), Russia, Siberia, Republic of Altai, Turochak District, Altai State Nature Biosphere Reserve, near cordon Baigazan, 51°45´32,7´´ N, 87°26´05,8´´ E, 481 m a.s.l., Padus avium and Betula, 1 October 2013; 1 male, 2 females, 1 juvenile (subadult female) (IBSS), 1 female (ASU), together with holotype, 3 October 2013; all leg. M.B. Sakhnevich.

Material re -examined ( specimens published by Mikhaljova et al. 2007). 1 male, 1 juvenile (subadult female), 1 fragment (IBSS), Russia, Siberia, Republic of Altai, Turochak District, Altai State Nature Biosphere Reserve, near cordon Baigazan, Padus avium, 3 September 2005, leg. M.B. Sakhnevich.

Diagnosis. Differs from congeners mainly by the gonopod opisthomere shape, with widely rounded caudal surface distally and short blunt apical process mesally combined with the gonopod mesomere distal part near hookshaped in lateral or mesal views.

Description. Male. Length 14–15 mm, vertical diameter 0.8–0.9 mm, with 40(–2) [2 specimens], 41(–2) [2 specimens], 42(–3) [1 specimen] body segments, excluding telson. One of the males is broken, because it is impossible to count the numbers of its body segments. Coloration brown with dark brown spots near ozopores. Front part of body with marbled transverse spots on metazonites. Clypeolabral region of head light. Basal part of head lightly marbled. Collum with two transversely, large, marbled spots. Segments in front of telson lighter. Antennae dark brown, legs light brown.

Eye patches composed of at least 24 ocelli. Labral setae 8+8. Antennae medium-sized, in situ extending behind to segments 4–5. Length ratios of antennomeres 2–7 as 3.8:2.8:2.3:2.8:1.8:1, width ratios as 0.7:0.9:0.9:1.2:1.2:1, respectively. Distodorsal corolla of antennomeres 5 and 6 each with not less than 4 and not less than 5 sensory bacilli, respectively. Gnathochilarium as typical of the genus. Four setae on each lamella lingualis arranged longitudinally: two distal setae somewhat moved away from the two basal ones.

8–9 striae on metazonital surface between dorsal midline and ozopore. Short caudal projection of telson epiproct somewhat flattened dorsoventrally, covered with relatively long setae, its tiny claw-shaped process directed caudad. Preanal ring of telson moderately setose. Anal valves relatively densely setose.

Legs with very delicately serrate sole pads on tibiae and postfemora; these pads gradually growing reduced towards posterior body end to totally disappear on last legs. Claw as typical of the genus.

Leg pair 1 (Fig. 15) and leg pair 2 (Fig. 16) as typical of the genus. Penes subtriangularly notched at tip.

Gonopods as in Figs 17–18, 21–22. Gonopod mesomere somewhat higher as compared with promere and opisthomere. Flattened promere (Fig. 18) with oval apex, its caudal surface covered by papillae nearly throughout. Flagellum medium length, filiform distally. Mesomere (Figs 21–22) slightly bent caudad; its front surface as plate, densely papillate, with longitudinal lowering along middle; its distal part near hook-shaped in lateral and/or mesal views; its apex with a fovea. Opisthomere distally with widely rounded caudal surface and with short blunt subapical process (a) mesally. Interior parabasal spine (s) relatively well-developed. Membranous velum (v) broad notched apically.

Female. Length 15–17 mm, vertical diameter 1.0– 1.2 mm, with 40(–2) [8 specimens], 41(–2) [5 specimens], 42(–3) [2 specimens] body segments, excluding telson. It is possible that females of different ages (including subadult females) are among the material. At least, specimens with bodies about 12 mm long, with 36(–2), 38(–2), 38(–3) segments excluding telson have smaller vulvae; they are listed as juveniles. Other nonsexual characters as in male.

Vulva (Figs 19–20). Operculum with subtriangular apical incision. Longitudinal row of setae on operculum each with 5–7 setae; 1–3 apical setae longest. 15–19 setae on posterior median bursal sclerite; 7–10 setae on lateral and mesal sclerites of the bursa together. Bursal setae gradually elongated to apex of vulva.

Name. The specific epithet refers to the locus typicus (cordon Baigazan in Altai State Nature Biosphere Reserve).

Remarks. Restudy of the male and subadult female from the Republic of Altai, Altai State Nature Biosphere Reserve, near cordon Baigazan, 3 September 2005, which were determined as Sibiriulus multinicus (see Mikhaljova et al. 2007), shows that the specimens belong to Sibiriulus baigazanensis sp. nov.