Omobrachyiulus fasciatus Vagalinski, 2021

Vagalinski, Boyan & Golovatch, Sergei I., 2021, The millipede tribe Brachyiulini in the Caucasus (Diplopoda, Julida, Julidae), ZooKeys 1058, pp. 1-127 : 1

Omobrachyiulus fasciatus Vagalinski sp. nov.

Figs 25 , 26 , 27

Material examined

(all from Russia). Holotype: ♂ (in two pieces, gonopods dissected, right antenna missing) (ZMUM), Republic of Adygea, Caucasian Nature Reserve, Lagonaki Plateau , Azishskiy Pass , forest, pitfall traps, 14-26.VIII.2013, Yu. Chumachenko leg. Paratypes: 1 ♂, 1 ♀, 1 subad. ♂, 2 juv. ♀♀ (SMNG 34136) (the male in 2 pieces, with dissected gonopods; the female unbroken, the subadult in two pieces, the juveniles unbroken), Republic of Adygea, Mt. Koryto , by a hut, 44°03'53"N, 40°21'02"E, 1600 m a.s.l., open Abies forests with dense undergrowth of herbs and shrubs, sifting leaf litter, 22.VIII.2005, K. Voigtländer leg. ; 1 ♂, 1 ♀ (SMNG 34142) (the male in 2 pieces, with dissected gonopods; the female in two pieces, right vulva dissected), Republic of Adygea, Shestakova Meadow , 44°01'56"N, 40°23'25"E, Abies , Acer , ferns, etc., pitfall traps, 24-25.VIII.2005, K. Voigtländer leg. ; 1 ♂, 1 juv. ♀ (SMNG 34154) (the male in head to ring 6 and rest of body, gonopods and hypoproct dissected; the juvenile unbroken), Republic of Adygea, a hut on the west bank of Afonka River , 44.0019°N, 40.4066°E, at a tree base, hand collecting, 27.VIII.2005, K. Voigtländer leg. ; 1 ♂ (NMNHS) (in head to ring 6, ring 7, and rest of body in three pieces; gonopods and hypoproct dissected), at Sakhray River , some 2 km E of Novoprokhladnoye, 44°08'11.4"N, 40°19'04.4"E, 635 m a.s.l., Fagus forest, in dead wood, hand collecting, 30.VIII.2005, K. Voigtländer leg. ; 2 ♂♂ (NHMD) (one in 2 pieces, gonopods, dissected, the other in 2 pieces, gonopods missing), 5 ♀♀ (NHMD) (some partly damaged), 3 juv. (NHMD), Krasnodar Province, ca. 9 km SW of Mount Fisht, Babuk-Aul , 43°53'26"N, 39°49'11"E, 560 m a.s.l., Castanea and Fagus forest, sifting leaf litter, 11.VII.2011, A. Solodovnikov leg. ; 2 ♂♂ (NHMD) (one unbroken, the other in five pieces, antenna, penis, leg 3, left flange of pleurotergum 7, and hypoproct dissected, opisthomeres and left promere prepared for SEM), 17 ♀♀ (NHMD) (some partly broken, one with dissected vulvae), 28 juv. and subad. (NHMD), Russia , Krasnodar Prov., ca. 7 km SW of Mount Fisht, 43°54.214'N, 39°50.507'E, 1200 m, Fagus and Rhododendron forest, sifting leaf litter, 14.VII.2011, A. Solodovnikov leg.

Diagnosis.

A species of Omobrachyiulus most similar to O. implicitus and O. lazanyiae sp. nov. by the overall shape of the promere, the weakly developed basoposterior process and mesomeroidal lobe of the opisthomere, and the broad, collar- or scarf-shaped, apical outgrowth of the basoposterior process which has a characteristic, wrinkled, lamellar part and partially covering the mesal side of the solenomere. Differs from these two species mainly by the apically clavate solenomere, and by the apical outgrowth of the opisthomeral basoposterior process consisting of a relatively narrow cockscomb-like distal part and a strongly developed scarf-shaped mesal part; as well as by other morphological details summarised in Table 1 .

Name.

From the Latin fascia, meaning scarf or band, after the strongly developed lamellar part of the apical outgrowth of the basoposterior process of the opisthomere, which is wrapped around the basomesal part of the solenomere. Adjective.

Description.

Measurements: holotype ♂ in S IX, 45+3+T, L = 15.5 mm, H = 1.05 mm; paratype ♂♂ in S VIII-IX, 44-46+1-3+T, L = 14-16 mm, H = 1-1.1 mm; paratype ♀♀ in S VIII-X, 41-46+2-3+T, L = 11.9-19.9 mm, H = 0.85-1.3 mm.

Colouration (Fig. 25A ): mostly brown, dorsum dark brown, prozonae dorsally with two short, transverse, blackish stripes, one each at frontal margin and near suture; metazonae with one longer, brown, transverse stripe, gradually narrowing and disappearing somewhat below ozopore level; dorsum with a blurred, blackish, axial line, this being more prominent on prozonae; with a dark brown spot above and in front of ozopore.

External structures: Eye patches in adults consisting of 30-40 ommatidia, mostly arranged in easily countable vertical rows. Vertigial, supralabral, and labral setae: two, four (one ♂ with five), and 16-18, respectively. Antennae 1.3-1.4 × as long as head in males and 1.2-1.3 × in females; antennomere 2> 4 = 5 ≥ 3. Gnathochilarium with a promentum separating both lamellae linguales over ca. 2/5 of their length, each latter with three or four setae in a longitudinal row; male stipites parabasally each with a longitudinal row of several short and stiff setae. Collum mostly smooth, with two or three broad shallow grooves near posterolateral corners, and with several densely set, oblique, shallow striae laterally at anterior margin.

Body rings barely vaulted. Prozonae with very short, fine, mostly parallel, longitudinal striae near pro-metazonal suture. Metazonae moderately deeply striated, n Schub = 8 or 9; metazonal setae 1/3 to nearly half of metazonal length. Ozopores set tightly behind pro-metazonal suture in more anterior rings, gradually moved further backwards, to nearly equal to their diameter behind the suture in caudalmost rings, sutures not being sinuous in front of ozopores. Tarsus of mid-body legs equal to, to slightly longer than, tibia, and nearly 3 × as long as apical claw.

Telson (Fig. 25B ): Epiproct long, wedge-like, with a well-developed, slightly clavate, hyaline tip turned dorsad, considerably surpassing longest paraproctal setae. Hypoproct (Fig. 26A ) rounded subtrapezoidal to semi-circular, ventrally with two distal paramedian setae; somewhat protruding past caudal margin of paraprocts in males, tightly fitting to their ventral side in females. Paraprocts sparsely to moderately setose.

Male sexual characters: Mandibular stipites weakly to moderately expanded, forming a blunt rectangular or slightly obtuse anterior corner. Leg pair 1 rather slender, parallel to slightly converging hooks. Adhesive leg pads large and crested, gradually reduced in caudal direction, postfemoral ones disappearing in caudal third of body, tibial ones discernible until caudalmost leg pairs; femora without modifications. Pleurotergum 7 ventrally forming rather elongated, distally somewhat clavate and broadly rounded lobes (Fig. 26B ) originating from the zone around pro-metazonal suture. Penis (Fig. 26C ) very short, with short diverging apical lobes and broad terminal lamellae directed caudad.

Gonopods (Figs 26D , 27 ): Promere (Fig. 27A, B ) rather slender, subequal in height to opisthomere, broadest at base, gradually tapering towards a narrow apex bent mesad; caudal surface with a strongly developed median ridge, and a very deep and relatively narrow median groove; with a small and not too deep distal groove, and a thick, strongly pronounced, distolateral lobe; flagellum (Fig. 27C and f in Fig. 27A ) slightly longer than height of promere, apically with several whorls of basad pointing denticles. Opisthomere (Figs 26D , 27D-G ) rather elongated; a basoposterior process present as a long and narrow, weakly developed lobe, distally forming a dentate cockscomb-like apical outgrowth, mesally extending into a strongly developed, soft, wrinkled, lamellar part, tightly enveloping the base of solenomere mesally and partly frontally; an anterior process absent; a mesomeroidal lobe barely discernible as a weakly developed rounded swelling slightly above opisthomeral mid-height, with a slender apicolateral part bent strongly mesad, considerably outreached by solenomere; mesal side with a large conoid lobe (presumably gonocoxal gland), and a not too deep anteromesal sinus frontal to the gland; several very long, erect and spiniform filaments parabasally along flagellum channel; solenomere relatively slender, bent caudomesad; apex somewhat clavate, consisting of two tightly contiguous, irregularly shaped, apical lobes; a minute tapering lobe bent basad and positioned subapically on mesal side.

Female sexual characters: Leg pairs 1 and 2 thicker and considerably shorter than following legs. Vulva (Fig. 26E ) symmetrical, strongly compressed on sides; bursa with an obtuse postero-apical margin; operculum as high as bursa; setation sparse, present only in distal parts of bursa and operculum. Receptaculum seminis consisting of a rather narrow and short central tube, and a very narrow and short, mostly straight, posterior tube leading to a minute, ovoid, posterior ampulla.

General distribution.

NWGC.

Remark.

The legs on body rings 2-6 of the paratype male from NMNHS were densely overgrown with fungi.

Figures

Figure 25. Omobrachyiulus fasciatus sp. nov., ♂ holotype A head and body rings 1 - 4 B telson, lateral views. Not to scale.

Figure 26. Omobrachyiulus fasciatus sp. nov., ♂ (A-D) and ♀ (E) paratypes from near Mount Fisht, Krasnodar Prov., Russia (ZMUC) A hypoproct, ventral view B left flange of pleurotergum 7, ventro-lateral view C penis, caudal view D distal part of right opisthomere, lateral, somewhat oral view E right vulva, mesal view. Scale bars: 0.2 mm (B, E), 0.1 mm (D), 0.06 mm (A, C). Abbreviations: ao apical outgrowth of basoposterior process, bpp basoposterior process, ct central tube, pa posterior ampulla, pt posterior tube, s solenomere.

Figure 27. Omobrachyiulus fasciatus sp. nov., gonopods of ♂ paratype from near Mount Fisht, Krasnodar Prov., Russia (NHMD) A left promere, caudal, somewhat lateral view B same, caudal view C apical part of flagellum D left opisthomere, mesal view E distal part of right opisthomere, caudo-mesal, somewhat apical view F distal part of left opisthomere, oral-mesal view G left opisthomere, caudo-mesal view. Scale bars: 0.1 mm (A, B, D), 0.05 mm (G), 0.02 mm (E, F) 0.01 mm (C). Abbreviations: ao apical outgrowth of basoposterior process, aol lamellar part of basoposterior process' apical outgrowth, bpp basoposterior process, dg distal groove, dl distolateral lobe, f flagellum, fc flagellum channel, g (supposed) gonocoxal gland, mg median groove, ml mesomeroidal lobe, mr median ridge, s solenomere, si anteromesal sinus.