Colchiobrachyiulus dioscoriadis (Lignau, 1915) Vagalinski & Golovatch, 2021

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

Colchiobrachyiulus dioscoriadis (Lignau, 1915) comb. nov.

Figs 2 , 3

Brachyiulus dioscoriadis Lignau, 1915: 382-387, text figs 12-20, tab. IV: figs 4, 5.

Chromatoiulus (Colchiobrachyiulus) dioscoriadis : Lohmander 1936: 113-114.

Chromatoiulus dioscoriadis : Kobakhidze 1964: 191; 1965: 393.

Megaphyllum dioscoriade (sic!): Talikadze 1984: 143.

Megaphyllum (Colchiobrachyiulus) dioscoriadis : Vagalinski and Lazányi 2018: 90-91, fig. 182.

Megaphyllum dioscoriadis : Chumachenko 2016: 409; Kokhia and Golovatch 2018: 40; 2020: 206.

Material examined

(ZMUM). Georgia: AR Abkhazia : 2 ♂♂, 1 juv., Gulripsh near Sukhumi , 24.X.1953, E. Borutzky leg. ; 2 ♂♂, 2 ♀♀, Ochamchira District, Jgerda, Kodorskiy Mountain Range , in litter and under bark, 21.IX.1985, I.A. Ushakov leg. ; 2 ♂♂, 3 ♀♀, Pitsunda-Myussera Nature Reserve, Myussera part, 20-130 m, mixed deciduous forest ( Castanea , Alnus , etc.), in litter, under bark and stones, 8-10.IV.1983 , SIG leg.; 1 ♂, 1 ♀, Pskhu-Gumistinskiy Nature Reserve, Gumistinskiy part, cordon Nizhniy Tsumur , 25.IX.1985, I.A. Ushakov leg. ; 3 ♂♂, 1 ♀, 1 juv., Sukhum District, Tsebelda , 300 m a.s.l., Carpinus , Acer and Buxus scrub, in litter, 19.VIII.1986 , SIG leg.; 6 ♂♂, 11 ♀♀, 3 juv., Sukhum District, Lake Amtkelis ( Azanta ) ca. 16 km N of Tsebelda, 550 m, Alnus forest, litter and under bark, 19.VIII.1986 , SIG leg.

Diagnosis.

A species of Colchiobrachiulus differing from its single known congener, C. montanus sp. nov., by the larger size (both sexes> 30 mm in length and 2 mm in height, vs. males <20 mm in length and 1.3 mm in height, and females <25 mm in length and 2 mm in height in C. montanus sp. nov.), the longer epiproct, and by certain details of gonopodal structure, more specifically, by the broader apex of the promere and its distomesal process significantly outreaching the apex, vs. the same being subequal to the apex in C. montanus sp. nov.; by the apical outgrowth of the opisthomere’s basoposterior process being relatively broader, with shorter branches at margin; and by the solenomere being bi- rather than unipartite in its distal section.

Descriptive notes.

Colouration (Fig. 2 ) mostly brown with reddish tinges; prozonae darker above ozopore level, contrasting lighter below it; metazonae more regularly brown-beige.

Epiproct (in Fig. 2B ) rather long, straight or slightly bent dorsad.

Gonopods (Fig. 3 ): Promere (Fig. 3A ) slender, slightly tapering towards a broadly rounded apex; mesal margin distally bearing a long and fine process significantly exceeding the main promeral apex; caudal surface with a weakly pronounced median ridge, a shallow and rather narrow median groove, and a deep and narrow distomesal groove; flagellum slightly longer than height of promere, apically micro-dentate. Opisthomere (Fig. 3C, E-H ) with a basoposterior process in the shape of a broad lobe running parallel to ending in a somewhat fan-like, apical outgrowth bearing numerous minute, papillose branches; anterior process long and slender, twisted at nearly 90° around solenomere, reaching somewhat higher than the latter; mesal side with a small lobe (presumably gonocoxal gland), and a shallow anteromesal sinus frontal to the gland; two sparse rows of not too long spiniform filaments at basomedial section of flagellum channel; solenomere slender, distally divided in two pointed apices of similar size.

Previous records from the Caucasus.

Georgia: AR Abkhazia: New Athos Monastery [S of Armianskoe Ushchelie]; at Besla [Basla] River [by Sukhumi]; Kamani Monastery [ca. 3 km N of Sukhumi]; Tsebelda; Lata; by the influx of Chkhalta River in Kodori River; village “Aschary” [Azhara]; on the right bank of Chkhalta River; near the influx of Gvandra River in Sekeni [must be Kodori] River (original localities); Cave Mikhailovskaya near Sukhumi ( Lohmander 1936); Tsebelda; Klych River valley, near waterfalls ( Kobakhidze 1965). [?!] Russia: Karachay-Cherkess Republic, influx of Marukha and “Adynge” rivers at 1400 m a.s.l. (original locality).

General distribution.

COLC-SWGC.

Remarks.

The original record from the valley of Marukha River in the Karachay-Cherkess Republic, Russia almost surely concerns Colchiobrachyiulus montanus sp. nov. All remaining records of C. dioscoriadis comb. nov. come from the Colchis Lowland and the southwestern foothills of the Greater Caucasus, and it is fairly unlikely that the species appears sympatric with its single known congener on the other side of the main Caucasus Major watershed.

Some of the examined females had large chunks of tar-like brownish substance behind leg pair 2, tightly stuck to the distal parts of the vulvae and covering the opening. These most likely represent 'copulatory plugs’ (see, e.g., Shear 2010; Enghoff 2018) or, more precisely, in this case 'copulatory caps’.

Figures

Figure 2. Colchiobrachyiulus dioscoriadis (Lignau, 1915), comb. nov. A mid-body rings B caudal end, lateral views. Not to scale. After Lignau (1915).

Figure 3. Colchiobrachyiulus dioscoriadis (Lignau, 1915), gonopods of ♂ from near Lake Amtkelis, Georgia (ZMUM) A right promere, caudal view B right opisthomere, mesal view C apical part of same aspect. Scale bars: 0.2 mm (A, B), 0.1 mm (C). Abbreviations: ap anterior process, ao apical outgrowth, bpp basoposterior process, dmg distomesal groove, dmp distomesal process, f flagellum, fc flagellum channel, g (supposed) gonocoxal gland, mg median groove, mr median ridge, s solenomere, sf spiniform filaments, si anteromesal sinus.