Omobrachyiulus mesorientalis, Gordana & Ambros, 2019

Vagalinski, B. & Golovatch, S. I., 2019, Omobrachyiulus mesorientalis sp. n., the first record of the millipede genus Omobrachyiulus Lohmander, 1936 in the Near East (Diplopoda: Julida: Julidae: Brachyiulini), Arthropoda Selecta 28 (1), pp. 1-7 : 2-6

Omobrachyiulus mesorientalis sp.n.

Figs 1–22 , Map.

Holotype ♂ (unbroken) ( ZMTA), Israel, Upper Galilee , Nahal Kziv (= Nahal Keziv), deciduous forest near stream, pitfall traps, NFS7-7, 17–31.I.1999, Michael Finkel leg.

Paratypes. All from the same locality and taken with pitfall traps by the same collector as the holotype: 1 ♂ (in 4 parts, gonopods dissected, right half prepared for SEM) ( NMNHS), NFS5- 9 , 17–31 .I.1999; 3 ♂♂ (intact, two unbroken, one with missing posterior half), 2 ♀♀, (one in 2 pieces; the other in 4 pieces, leg-pair 2 with vulvae dissected, right vulva prepared for SEM), 1 juv. ♂ (unbroken) ( ZMTA), B4-3 , 12.XII.1998 – 2.I.1999; 1 ♂ (with missing caudal half, penis dissected), 3 ♀♀ (one unbroken, the others in 2 pieces) ( NMNHS), NFS6-10 , 12.XII.1998 – 2.I.1999; 1 ♂ (unbroken) ( ZMUM), NFS7-2 ; 12.XII.1998 – 2.I.1999; 1 ♂ (unbroken) ( ZMUM), NFS6-5 , 12.XII.1998 – 2.I.1999; 5 ♂♂ (two unbroken, two in 2 parts), 1 premature ♀ (unbroken), 4 juv. (two unbroken, two in 2 parts) ( ZMTA), 1 ♂ ( ZMUC), B4-1 , 17–31 .I.1999; 1 ♂; 3 ♀♀ (one in 2 parts with dissected vulvae), 1 fragm. juv. ( ZMTA), NFS7-3 , 17 – 31.1.1999; 1 ♀ ( ZMUC), B4-5 , 17 .I–31.I.1999.

2 ♂♂ (prep. 4/2004SG and prep. 18/2003SG), 1 juv. ♂ ( ZMUM), Mt Meron , N slope, Quercus forest, 6.III.2003, S. Golovatch leg.

1 ♂ (in 2 parts, gonopods dissected), 1 ♀ ( NMNHS), Lebanon, near Jeita , 10.VII.1972, P. Beron leg.

Non-types. All from the same locality and taken with pitfall traps by the same collector as the holotype: 1 ♀ ( ZMTA), NFS7-8, 12.XII.1998 – 2.I.1999; 1 ♂ (fragmented), 2 ♀♀, 1 fragment ( ZMTA), NFS7-5 , 12.XII.1998 – 2.I.1999; 2 juv. ( ZMTA), NFS6-8 , 17– 31 .I.1999; 2 juv. ( ZMTA), NFS7-8 , 12.XII.1998 – 2.I.1999; 1 juv. ♂ ( ZMTA), NFS7-8 , 17–31 .X.1998; 1 ♀ ( ZMUM), NFS7-4 , 12.XII.1998 – 2.I.1999; 1 ♀ ( ZMTA), NFS5-10 , 17–31 .X.1998; 1 juv. ♀ ( ZMTA), B4-10 , 12.XII.1998 – 2.I.1999; 1 fragmented ♂ ( ZMTA), NFS7–8 , 17–31 .X.1998, 1 fragmented ♀ ( ZMTA), NFS5- 6 ; 12.XII.1998 – 2.I.1999; 1 ♂, 2 ♀♀ ( ZMUM), NFS5-6 , 17– 31 .I.1999; 1 ♀, 1 juv., 1 ♂ (fragmented), 3 ♀♀, 3 juv. ( ZMTA), NFS6-10 , 12.XII.1998 – 2.I.1999.

DIAGNOSIS. A species of the genus Omobrachyiulus Lohmander, 1936 , as defined by Vagalinski & Lazányi [2018], with the exception of the opisthomeral basoposterior process, which is completely vestigial in the new species. Differs from all congeners mostly by the rounded, sole-shaped promere, and in the opisthomere having a pointed, microserrate, anterior process, and a strongly compressed, lobe-like remnant of the basoposterior process, this latter being devoid of a freely protruding apical part; as well as by the hypoproct being subtriangular rather than trapezoidal or rounded.

ETYMOLOGY. Derived from its Near East provenance.

DESCRIPTION. Measurements: holotype ♂ in S X, 56+2+T, l = 32 mm, h = 1.9 mm. Paratype ♂♂ in S IX–XI, 53–58+2+T, l = 24–37mm, h = 1.7–2.15 mm. Paratype ♀♀ in S X, 54–58+2+T, l = 29–37 mm, h = 2.3–2.9 mm.

Colouration: Mostly different shades of brown ( Figs 1– 4 ); prozonae darker than metazonae, chocolate brown around ozopores, dark brown-grey on dorsum; head with a blackish band between eye patches; collum chocolate brown, darker along margins; pre-anal ring darker than remaining body rings; legs and antennae brownish beige; a continuous blackish axial line.

External structures: 2 frontal, 4 supralabral (with an additional 5 th median seta in one paratype ♂), 24–35 labral setae. Antennomeres 3, 4 and 5 subequal in length, ca 0.7 times as long as 2, and 1.6–2.2 times as long as 6. Gnathochilarium of normal julid appearance; promentum relatively large: 0.3–0.4 times as long as entire gnathochilarium; 4 setae on each lingual lamella. Collum smooth dorsally, with several, up to 15 short and shallow striae near posterolateral corner; lateral section of anterior margin characteristically concave.

Prozonae with scattered, short, shallow, non-parallel striae. Metazonae deeply striated, with 10–11 striae in a square with sides equal to metazonal length just below ozopore level; hind margins with a dense whorl of setae, ca 1/3–3/5 of metazonal length. Ozopores placed tight behind pro-metazonal suture in anterior to mid-body rings, but slightly further back (ca half of their diameter) in posterior rings; suture not or very slightly incised in front of ozopores. Tarsi of mid-body legs 0.75–0.9 as long as tibiae.

Telson ( Fig. 1 ): Epiproct straight, somewhat compressed dorsoventrally (this being more pronounced in females), ending with a long, slender, pointed, hyaline tip (often broken off) turned somewhat ventrad, slightly surpassing the longest anal setae, densely setose. Hypoproct broad, subtriangular, with a narrow, sharply pointed tip protruding more than 1/3 behind rear margin of paraprocts in males, this being blunt and barely protruding in females; ventral face densely setose. Paraprocts densely setose, without distinct rows of short and stiff setae along caudal margins.

Male sexual characters: Mandibular stipites ( Figs 1, 2 ) moderately enlarged, protruding mostly anteriad, forming a narrowly rounded, anteroventral corner. Leg-pair 1 ( Fig. 5 ) typical parallel hooks with slightly diverging tibial outgrowths, without tarsal remnants. Leg-pair 2 ( Fig. 6 ) and following pairs with two adhesive pads, one each on postfemur and tibia. Leg-pairs 2–7 with pronouncedly crested tibial pads, with a distinct distal lobe partly covering the tarsus. Pleurotergum 7 ( Fig. 7 ) ventrally forming rather small, subtriangular plates originating mostly from metazona and protruding ventrad behind gonopods. Penis ( Figs 8, 9 ) stout, only slightly compressed sagittally, broadest at base, conspicuously constricted near middle; apical lobes welldifferentiated, diverging, ending up in subtriangular terminal lamellae.

Gonopods ( Figs 10–19 ): In situ ca 1/3 jutting out of gonopodal sinus, protruding completely ventrad, solenomere slightly longer than promere. Promere ( Figs 10 , 14 & 15 ) roughly sole-shaped, slightly bent mesad, narrowing basad; with a pronounced, but very short, median ridge (mr), and a very deep and narrow median groove (mg); and with a broad and long distal groove (dg); the two promeres basally very tightly fused to each other. Flagellum (fl) slightly longer than promere’s height, thin, almost thread-like distally. Opisthomere ( Figs 11, 13 , 16–19 , and in Fig. 12 ) completely devoid of a basoposterior process, the latter represented only by a weakly pronounced lobe, lacking a freely protruding apical part; mesomeroidal lobe (ml) massive, with a broad and flattened anterior face, protruding apically into a pointed, horn-like process (mlp); with a slender, sharply pointed, microserrated, anterior process (ap) originating immediately distal to mesomeroidal lobe, directed anterodistad. Solenomere (s) long and slender, ending up in a lamellar, somewhat folded structure; anteromedially bearing a fine and pointed anterior process (asp), more or less turned anteriad apically; a compact group of short spiniform filaments (sf) behind flagellum channel (fc) at solenomeral mid-height, and a sparse row of similar spines frontal to channel.

Female sexual characters: Leg pairs 1 and, to a lesser extent, 2 in mature females thicker than following legs. Vulva ( Figs 20, 21 ) rather stout and compact, slightly compressed on sides; bursa slightly asymmetrical: lateral valve somewhat higher than mesal one; side sclerites apically ending up in large hyaline protrusions; operculum narrow, placed entirely on top of bursa; operculum as high as, or slightly exceeding, bursa; both bursa and operculum densely covered with long setae. Receptaculum seminis ( Fig. 22 ) consisting of a nearly straight, finger-shaped, central tube (ct), and a thin, strongly twisted, posterior tube (pt) ending up in a rather spacious, bottle-like, posterior ampulla (pa).

NOTE. The gonopods of the male from Lebanon slightly differ from those in the Israeli specimens, in particular by the promere being more slender and apically tapering rather than broadly rounded, and by the anterior solenomeral process being very slightly, rather than abruptly, turned anteriad. However, these details can hardly be regarded as anything more than intraspecific variations.

Figures

Figs 1–4. Habitus of Omobrachyiulus mesorientalis sp.n., male paratypes from Nahal Kziv: 1 — whole body, lateral view; 2 — anterior part of body, lateral view; 3–4 — mid-body, dorsal and lateral views, respectively. Pictures by J. Wytwer, taken not to scale. Рис. 1–4. ОбЩий вид Omobrachyiulus mesorientalis sp.n., самцы-паратипы иЗ Nahal Kziv: 1 — тело целиком, сбоку; 2 — переднЯЯ часть тела, сбоку; 3–4 — середина тела, соответственно сверху и сбоку. Сфотографировано J. Wytwer, беЗ масШтаба.

Figs 5–9. Non-gonopodal characters of Omobrachyiulus mesorientalis sp.n., male paratypes from Nahal Kziv: 5 — right leg 1, mesal view; 6 — left leg 2, oral view; 7 — left edge of pleurotergum 7, ventrolateral view; 8–9 — penis, caudal and lateral views, respectively. Scale bars: 0.2 mm. Рис. 5–9. Не свЯЗанные с гоноподами приЗнаки у Omobrachyiulus mesorientalis sp.n., самцы-паратипы иЗ Nahal Keziv: 5 — праваЯ нога 1, иЗнутри; 6 — леваЯ нога 2, спереди; 7 — левый край плейротергита 7, одновременно сниЗу и сбоку; 8–9 — пенис, соответственно сЗади и сбоку. МасШтаб: 0,2 мм.

Figs 10–13. Gonopods of Omobrachyiulus mesorientalis sp.n., male paratype from Nahal Kziv: 10 — left promere, caudal view; 11 — right opisthomere, lateral view; 12 — left pair of gonopods, mesal view; 13 — distal part of right opisthomere, oral view. Abbreviations: ap — anterior process, asp — anterior process of solenomere, dg — distal groove, fl — flagellum, mg — median groove, ml — mesomeroidal lobe, mlp — apical process of mesomeroidal lobe, mr — median ridge, s — solenomere. Scale bar: 0.2 mm. Рис. 10–13. Гоноподы Omobrachyiulus mesorientalis sp.n., самец-паратип иЗ Nahal Kziv: 10 — левый промер, сЗади; 11 — правый опистомер, сбоку; 12 — леваЯ пара гоноподов, иЗнутри; 13 — дистальнаЯ часть правого опистомера, спереди. ОбоЗначе- ниЯ: ap — передний отросток, asp — передний отросток соленомера, dg — дистальный желобок, fl — жгутик, mg — медиальный желобок, ml — меЗомероиднаЯ долЯ, mlp — верШинный отросток меЗомероидной доли, mr — медиальный гребень, s — солено- мер. МасШтаб: 0,2 мм.

Figs 14–19. Gonopods of Omobrachyiulus mesorientalis sp.n., male paratypes from Jeita (14, 19) and Nahal Kziv (15–18): 14 — left promere, caudal view; 15 — right promere, caudal view; 16–18 — right opisthomere, oral, mesal and mesocaudal views, respectively; 19 — distal part of left opisthomere, lateral view. Abbreviations: ap — anterior process, asp — anterior process of solenomere, dg — distal groove, fl — flagellum, fc — flagellum channel, mg — median groove, ml — mesomeroidal lobe, mlp — apical process of mesomeroidal lobe, mr — median ridge, s — solenomere, sf — spiniform filaments. Scale bars 0.1 mm (15, 16, 18) and 0.2 mm (14, 17, 19). Рис. 14–19. Гоноподы Omobrachyiulus mesorientalis sp.n., самцы-паратипы иЗ Jeita (14, 19) и Nahal Kziv (15–18): 14 — левый промер, сЗади; 15 — правый промер, сЗади; 16–18 — правый опистомер, соответственно спереди, иЗнутри и одновременно иЗнутри и сЗади; 19 — дистальнаЯ часть левого опистомера, сбоку. ОбоЗначениЯ: ap — передний отросток, asp — передний отросток соленомера, dg — дистальный желобок, fl — жгутик, fc — канал жгутика; mg — медиальный желобок, ml — меЗомеро- иднаЯ долЯ, mlp — верШинный отросток меЗомероидной доли, mr — медиальный гребень, s — соленомер; sf — Шиповидные выросты. МасШтаб: 0,1 мм (15, 16, 18) и 0,2 мм (14, 17, 19).

Figs 20–22. Vulvae of Omobrachyiulus mesorientalis sp.n., paratype female from Nahal Kziv: 20–21 — right vulva, mesocaudal and caudolateral views, respectively; 22 — receptaculum seminis. Abbreviations: ct — central tube, o — opening, pa — posterior ampulla, pt — posterior tube. Scale bars: 0.2 mm (22); 0.1 mm (20, 21). Рис. 20–22. Вульвы у Omobrachyiulus mesorientalis sp.n., самка-паратип иЗ Nahal Kziv: 20–21 — праваЯ вульва, соответствен- но одновременно иЗнутри и сЗади и сЗади и сбоку; 22 — семЯприемник. ОбоЗначениЯ: ct — центральнаЯ трубка, o — отверстие, pa — ЗаднЯЯ ампула, pt — ЗаднЯЯ трубка. МасШтаб: 0,2 мм (22); 0,1 мм (20, 21).