Omobrachyiulus faxifer 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 faxifer Vagalinski sp. nov.

Figs 32 , 33 , 34

Material examined

(all from Russia): Holotype: ♂ (unbroken) (ZMUM), Republic of Adygea, Caucasian Biosphere Nature Reserve, Lagonaki Plateau , Azishskiy Pass , subalpine meadow, pitfall traps, 26.VIII-23.IX.2013, Yu. Chumachenko leg. Paratypes: 1 ♂ (SMNG) (in 2 pieces, with dissected gonopods), Stavropol, Tamanskaya Dacha Forest, near Komsomolskiy Reservoir , 45.0481°N, 41.9567°E, 530 m a.s.l., Quercus , Carpinus , Acer , etc., 22.VIII.2012, F. Walther leg. ; 1 ♂ (SMNG 34143) (in 3 pieces, with dissected gonopods), Republic of Adygea, Shestakova Meadow , 44°01'56"N, 40°23'25"E, grassy area with sparse Fagus and Betula next to a brook, pitfall traps, 24-25.VIII.2005, K. Voigtländer leg. ; 2 ♂♂ (ZMUM) (one in 2, the other in 3 pieces, with dissected gonopods), 1 ♂ (unbroken) (NHMD), same collecting data as for holotype ; 1 ♂ (ZMUM) (in head to collum and 4 pieces, gonopods and penis dissected), 1 juv. (ZMUM), Republic of Adygea, Caucasian Biosphere Nature Reserve, Lagonaki Plateau , Instruktorskaya Cleft , forest, pitfall traps, 23.VIII-11.IX.2013, Yu. Chumachenko leg. ; 2 ♂♂ (ZMUM) (one in two pieces with dissected gonopods, the other in head, collum to ring 2, ring 3 to ring 6, and rest of body, gonopods prepared for SEM), Stavropol, Mamayskiy Forest , 31.III.2013, R. Zuev leg. ; 1 ♂ (NMNHS) (in two pieces with dissected gonopods), Stavropol, Tamanskaya Dacha Forest , 10.IX.2013, R.V. Zuev leg. ; 1 ♂ (ZMUM) (in 2 pieces with dissected gonopods), 3 adult ♀♀ (ZMUM) (two unbroken, one in 2 pieces with dissected vulvae), 2 subadult ♀♀ (ZMUM), Stavropol, Tamanskaya Dacha Forest , Quercus , Acer , Carpinus , 01.VI.2014, R.V. Zuev leg.

Diagnosis.

A species of Omobrachyiulus differing from congeners mainly by the apically strongly enlarged and hollow solenomere, postero-apically bearing a fine, pointed, sigmoid process, and by the well-developed lateral lobe of the opisthomere ending with a pointed process which is turned anteriad.

Name.

Meaning torch-bearer in Latin, after the resemblance of the solenomere to a burning torch, the flame being represented by a fine apical sigmoid process. Noun in apposition.

Description.

Measurements: holotype ♂ in S IX, 42+1+T, H = 1.1 mm, L = 18.5 mm; paratype ♂♂ in S VIII-IX, 40-43+1+T, L = 15-19 mm, H = 1.05-1.3 mm; paratype ♀♀ in S VIII-IX, 42-45+0-1+T, L = 15-21 mm; H = 1.5-1.8 mm.

Colouration (Fig. 32 ): Head and collum with the usual pattern; prozonae brown-beige, dorsally with a narrow, dark grey, transverse band near pro-metazonal suture, and with a blackish spot in front of ozopores; metazonae brownish, darker in anterior section, light ochre-brown at hind margin; dorsum with a continuous, blackish, axial line; pre-anal ring dark brown, paraprocts lighter brown-beige.

External structures: Eye patches in adults consisting of 22-35 well-pronounced ommatidia mostly arranged in easily countable vertical rows. Vertigial, supralabral, and labral setae: two, four, and 22-28, respectively. Antennae (in Fig. 32B ) 1.6-1.7 × as long as head in males and 1.3-1.4 × in females; antennomere 2> 5 ≥ 3 ≥ 4> 6. Gnathochilarium with a relatively large promentum separating both lamellae linguales nearly halfway, each latter with two or three setae in a longitudinal row. Collum mostly smooth, with only tree or four striae near posterolateral corners.

Body rings gently vaulted. Prozonae with very short, fine, mostly purely longitudinal striae in posterior sections. Metazonae rather deeply striated, n Schub = 6 or 7 in males and 7 or 8 in females; metazonal setae 1/2-2/3 of metazonal length. Ozopores touching or set barely behind pro-metazonal sutures along entire body; sutures not sinuous in front of ozopores. Tarsus of mid-body legs equal to, to slightly longer than, tibia, and ca. 3 × as long as apical claw.

Telson (Fig. 32C ): Epiproct mostly straight, distally slightly turned ventrad, wedge- rather than roof-like, ending with an indistinct, blunt, hyaline tip reaching the level of longest anal setae. Hypoproct (Fig. 33A ) in males broad trapezoidal with broadly rounded corners, margin coarse, sometimes forming three small blunt denticles, considerably protruding past rear margin of paraprocts; same being broader, with an always smooth margin, barely protruding behind rear margin of paraprocts. Paraprocts covered with relatively sparse long setae; without distinct rows of shorter setae along caudal margins.

Male sexual characters: Mandibular stipites (in Fig. 32B ) considerably expanded, forming a distinct, blunt or narrowly rounded, anteroventral corner. Leg pair 1 compact, parallel hooks, slightly turned mesad. Legs 2 (Fig. 33B ) and following pairs ventrally with well-developed crested adhesive pads, postfemoral ones vanishing in caudal third of body; femora 2 basoventrally with small bumps (black arrow), femora of other legs without modifications. Pleurotergum 7 ventrally forming broad shovel-like lobes (Fig. 33C ) originating mostly from metazona, directed ventromesad, touching one another behind gonopods. Penis (Fig. 33D ) nearly as long as broad, compressed antero-caudally, with short diverging apical lobes ending in rather large terminal lamellae directed distad.

Gonopods (Figs 33E , 34 ): Promere (Fig. 34A ) as high as opisthomere, broadest at base, abruptly narrowing after an incision at lateral margin’s mid-proximal section; lateral margin distally slightly convex, mesal one very gently sigmoid; apex broad, with a nearly rectangular meso-apical corner; caudal surface with a strongly pronounced median ridge, a deep and very narrow median groove, and a deep, rounded, distal groove; flagellum somewhat longer than height of promere, apically bearing blunt denticles directed basad, arranged in two or three transverse rows. Opisthomere (Figs 33E , 34B-F ) moderately elongated; basoposterior process moderately developed, its apical outgrowth large, forming two parts: a smaller median one, and a larger mesal one bent strongly basofrontad, covering the basomesal side of solenomere like a hood; both parts distally with several small conical denticles; an anterior process absent; mesomeroidal lobe well-developed, narrow, ridge-like in its proximal part, distally widening in a pyramidal structure with a distinct apex; lateral side with a well-developed ridge-like lobe apically forming a pointed horn-like process bent frontad; mesal side with a relatively large, subtriangular lobe (presumably gonocoxal gland), and a shallow, indistinct, anteromesal sinus; moderately long, erect, spiniform filaments present over most of flagellum channel; solenomere unipartite, apically clavate and deeply hollow, with a fine sigmoid apical process.

Female sexual characters: Vulva (Fig. 33F ) rather short and compact, symmetrical; operculum slightly higher than bursa, both bursa and operculum ending up with broad and rather short hyaline protrusions; setation dense throughout. Receptaculum seminis consisting of a very large, sack-shaped, central tube, and a very long, narrow, somewhat folded, posterior tube leading to a nearly spherical posterior ampulla.

General distribution.

NWGC-WCIS.

Figures

Figure 32. Omobrachyiulus faxifer sp. nov., ♂ holotype (A) and ♂ paratype from Lagonaki Plateau, Adygea, Russia (ZMUC) (B) A habitus, mostly lateral view B head and collum, lateral, slightly frontal view C telson, lateral view. Not to scale.

Figure 33. Omobrachyiulus faxifer sp. nov., ♂ paratypes from Lagonaki Plateau, Adygea, Russia (ZMUM) (A-D) and Mamayskiy Forest, Stavropol, Russia (ZMUM) (E), and ♀ paratype (F) from Tamanskaya Dacha Forest, Stavropol, Russia (ZMUM) A hypoproct, ventral view B leg 2 C left flange of pleurotergum 7, ventro-lateral view D penis, caudal view E left opisthomere, oral-mesal view F right vulva, caudal view. Scale bars: 0.2 mm (A, C, D), 0.1 mm (B, E, F). Abbreviations: ao apical outgrowth of basoposterior process, bpp basoposterior process, ct central tube fc flagellum channel, g (supposed) gonocoxal gland, lh horn-like process of lateral lobe, ml mesomeroidal lobe, pa posterior ampulla pt posterior tube s solenomere, sc seminal channel, sf spiniform filaments, si anteromesal sinus, sp sigmoid process of solenomere.

Figure 34. Omobrachyiulus faxifer sp. nov., gonopods of ♂ paratype from Mamayskiy Forest, Stavropol, Russia (ZMUM) A left promere (somewhat damaged in proximal part), caudal view B apical part of flagellum C left opisthomere, mesal view D right opisthomere, lateral view E distal part of left opisthomere, mesal view F distal part of right opisthomere, lateral view. Scale bars: 0.1 mm (A, C, D), 0.05 mm (E, F), 0.01 mm (B). Abbreviations: ao apical outgrowth of basoposterior process, bpp basoposterior process, dg distal groove, f flagellum, fc flagellum channel, g (supposed) gonocoxal gland, lh horn-like process of lateral lobe, lp lateral lobe, mg median groove, ml mesomeroidal lobe, mr median ridge, s solenomere, si anteromesal sinus, sp sigmoid process of solenomere.