Omobrachyiulus implicitus (Lohmander, 1936)

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

Omobrachyiulus implicitus (Lohmander, 1936)

Fig. 24

Chromatoiulus (Omobrachyiulus) implicitus Lohmander, 1936: 140-143, figs 120-122.

Chromatoiulus (Omobrachyiulus) implicitus : Lang 1959: 1791.

Chromatoiulus implicitus : Kobakhidze 1964: 191; 1965: 394.

Chromatoiulus implicitus ritsensis Golovatch, 1981: 108-110, figs 8-11, syn. nov.

Megaphyllum implicitum implicitum : Talikadze 1984: 143.

Megaphyllum implicitum ritsense : Talikadze 1984: 143.

Megaphyllum implicatum (sic!): Chumachenko 2016: 409.

Omobrachyiulus implicitus : Vagalinski and Lazányi 2018: 98; Kokhia and Golovatch 2018: 41; 2020: 206.

Material examined.

Georgia: AR Abkhazia : 6 ♂♂, 7 ♀♀, 1 juv. (ZMUM), Pitsunda-Myussera Nature Reserve, Myussera part, 120-130 m a.s.l., mixed deciduous forest ( Castanea , Alnus etc.), in litter, under bark and stones, 8-10.IV.1983 , SIG leg.; 1 ♂, 3 ♀♀, 1 juv. (ZMUM), Avadhara , 1600-1700 m a.s.l., Abies , Fagus , fern, Rubus , Galium , 18.IX.1985, I.A. Ushakov leg. ; 2 ♂♂, 3 ♀♀, 1 juv. (ZMUM), N of Lake Ritsa , Abies , Fagus , in litter, 13.IX.1985, I.A. Ushakov leg. Russia: Republic of Adygea : 1 ♂, 2 ♀♀ (AE), near Maykop, Polkovnitskaya Ravine , 44°20.72'N, 40°11.37'E, pitfall traps, 01-17.X.2011, Yu. Chumachenko leg. ; 1 ♂, 1 juv. ♂ (AE), same place, collecting method and collector, 17.X-01.XI.2011; 1 ♂, 1 juv. (ZMUM), confluence of Kisha and Belaya rivers, mixed forest, ca. 200 m a.s.l., 11.VI.2013, R. V. Zuev leg. ; 5 ♂♂, 6 ♀♀, 5 juv. (ZMUM), Krasnodar Province, 5.5 km NE of Krasnaya Polyana, lower course of Achipse River , 43°15'25"N, 40°15'25"E, ca. 600 m a.s.l., 19-23.VIII.2014, K. Makarov and A. Matalin leg.

Diagnosis.

A species of Omobrachyiulus most similar to O. fasciatus sp. nov. 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, the latter having a characteristic, wrinkled, lamellar part partially covering the mesal side of the solenomere. Differs from these two species mainly by the very slender and tripartite solenomere apically forked into two mostly symmetrical, strongly diverging branches, with a minute ear-like lobe mesally at the base of the bifurcation; and by the distally broader promere with a very broad and deep distal groove on the caudal surface, this being a small pit in O. fasciatus sp. nov. and O. lazanyiae sp. nov.; as well as in other gonopod details summarised in a tabular key (Table 1 ) to these three species.

Descriptive notes.

Promere (Fig. 24A ) slightly sigmoid, of more or less same width all along, ending in a thick and broadly rounded apex; median ridge strongly pronounced and arched, median groove deep and narrow, distal groove deep and broad; flagellum slightly longer than height of promere, apically sparsely micro-dentate (Fig. 24B ). Opisthomere (Fig. 24C-F ) rather slender; basoposterior process weakly pronounced, lamellar, ending with a collar-like apical outgrowth having a rather small, wrinkled, lamellar part; mesomeroidal lobe moderately pronounced, with a concave apical margin; mesal side with a stout lobe (presumably gonocoxal gland) and a rather deep anteromesal sinus; flagellum channel with only a few minute spiniform filaments; solenomere long and slender, apically forked into two diverging, somewhat flattened branches of nearly equal size and shape; a minute, ear-shaped lobe mesally at the base of the bifurcation.

Previous records from the Caucasus.

Georgia, AR Abkhazia, Gagry (type locality), near Lake Ritsa (the type locality of O. i. ritsensis )

General distribution.

WECA.

Remarks.

The species is new to the fauna of Russia.

The subspecies O. i. ritsensis was described by Golovatch (1981) from the environs of Lake Ritsa, AR Abkhazia. The author listed the sparser metazonal striations, the slightly upwards bent epiproct and the different shape of the promere as the main diagnostic characters that distinguish ristensis from the typical form. The gonopods of all examined males, including the topotypic material from north of Lake Ritsa, show no significant differences from each other and they all match well the original descriptions and drawings of both the typical O. implicitus and O. i. ritsensis . On the other hand, the two aforementioned external somatic characters cannot alone reliably delimit a subspecies, as in Julidae they normally display some variations even within one population. We thus formally synonymise O. implicitus ritsensis with the typical O. implicitus , syn. nov.

Figures

Figure 24. Omobrachyiulus implicitus (Lohmander, 1936), gonopods of ♂ from Myussera, AR Abkhazia, Georgia (ZMUM) A right promere, caudal view B apical part of flagellum C right opisthomere, mesal view D distal part of the same aspect E right opisthomere, oral-mesal view F same, oral view. Scale bars: 0.1 mm (A, C, E, F), 0.05 mm (D), 0.01 mm (B). Abbreviations: ao apical outgrowth of basoposterior process, 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.

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.

Figure 28. Omobrachyiulus lazanyiae sp. nov., ♂ holotype A head and body rings 1 - 3, lateral, slightly dorsal view B telson, lateral view. Not to scale.

Figure 29. Omobrachyiulus lazanyiae sp. nov., ♂ paratype (SMNG) A hypoproct (basal corners broken off), ventral view B right leg 1, mesal view C right flange of pleurotergum 7, ventro-lateral view D right opisthomere, mesal, somewhat oral view. Scale bars: 0.2 mm (D), 0.1 mm (A-C). Abbreviations: ao apical outgrowth of basoposterior process, aol lamellar part of basoposterior process' apical outgrowth, fc flagellum channel, g (supposed) gonocoxal gland, ml mesomeroidal lobe, s solenomere, sc seminal channel, sf spiniform filaments, sl mesal lobe of solenomere.

Figure 30. Omobrachyiulus lazanyiae sp. nov., gonopods of ♂ paratype (SMNG) A right promere (flagellum broken off), caudal view B right opisthomere, mesal view C left opisthomere, latero-oral view D apical part of right opisthomere, mesal view E distal part of left opisthomere, latero-oral view. Scale bars: 0.1 mm (A-C), 0.05 mm (E), 0.02 mm (D). Abbreviations: ao apical outgrowth of basoposterior process, aol lamellar part of basoposterior process' apical outgrowth, bpp basoposterior process, dg distal groove, fc flagellum channel, g (supposed) gonocoxal gland, mg median groove, ml mesomeroidal lobe, mr median ridge, s solenomere, sc seminal channel, sf spiniform filaments, si anteromesal sinus, sl mesal lobe of solenomere.