Omobrachyiulus kvavadzei 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 kvavadzei Vagalinski sp. nov.

Figs 38 , 39 , 40

Material examined

(all from Georgia). Holotype: ♂ (unbroken) (ZMUM), AR Ajara, Kintrishi Nature Reserve, mouth of Khekpara River , 2.X.1984, E. Kvavadze leg. Paratypes: 8 ♂♂ (ZMUM) (five unbroken, one in head to ring 3, ring 4 to pleurotergum 7, and rest of body, with dissected penis and gonopods, one in head to pleurotergum 7 and rest of body, gonopods dissected, one broken in 2 pieces, one in 3 pieces), 1 ♂ (NHMD) (unbroken), 1 ♂ (NMNHS) (unbroken), 1 ♂ (IBER) (unbroken), 8 ♀♀ (ZMUM) (six unbroken,two in 2 pieces, one in head to ring 3 and rest of body, one in 2 pieces, head missing), 1 ♀ (NHMD) (unbroken), 1 ♀ (NMNHS) (unbroken), 1 ♀ (IBER) (unbroken), 2 juv. (ZMUM), same collecting data as for holotype ; 1 ♂ (in head to ring 6 and rest of body), 4 ♀♀ (one broken in two pieces, the rest unbroken) (ZMUM), AR Ajara, Kintrishi Reserve, Zeraboseli , 450-600 m a. s. l., deciduous forest, litter and under stones, 13.X.1981 , SIG leg.; 4 ♂♂ (one in head to ring 6 + rest of body, gonopods dissected; one broken in two pieces, the rest unbroken), 2 ♀♀ (one broken in two pieces, the other unbroken), 2 juv. (ZMUM), same area, 800 m a. s. l., same date and collector; 1 ♂ (in leg to ring 6 and rest of body, gonopods dissected), 2 ♀♀ (one in 2 pieces, the other unbroken), 1 juv. (ZMUM), AR Ajara, Batumi Botanical Garden , 13.X.1978 , SIG leg.; 1 ♂ (ZMUM) (in head to ring 6, pleurotergum 7 to ring 9, and rest of body, opisthomeres and left promere prepared for SEM), AR Ajara, E of Kobuleti , 3 km SE of Chakhati, deciduous forest, near a spring, litter and under stones, 14.X.1981 , SIG leg.; 1 ♂ (ZMUM) (in head to pleurotergum 7 and rest of body, gonopods dissected), Samtskhe-Javakheti, 15 km W of Adigeni, Abieas , Picea , Fagus , Acer etc. forest, 1500-1700 m, litter, logs, under stones, 14-15.V.1983 , SIG leg.

Non-types

(ZMUM): 1 ♂, 7 ♀♀ (ZMUM) (all fragmented in 2 or more pieces), Georgia, AR Ajara, Kintrishi Nature Reserve, Zeraboseli, 450-600 m a. s. l., 1-3.VI.1981, SIG and J. Martens leg.

Diagnosis.

A species of Omobrachyiulus most similar to O. sevangensis comb. nov., O. ponticus sp. nov., and O. trochiloides sp. nov. in gonopod structure, as well as in the shape of the male telson. Differs from all these species mainly by the opisthomere having a bifid anterior process and a better developed, higher mesomeroidal lobe ending with a distinct apicolateral part.

Name.

In memory of Eristo Kvavadze (1940-2013), a specialist in earthworms and biological control, the collector of the bulk of the material of this new species.

Description.

Measurements: holotype ♂ in S IX, 40+1+T, L = 15.5 mm, H = 1.05 mm; paratypes in S VIII-IX, 39-42+1-2+T, L = 13-16.5 mm and 19-24 mm, H = 1-1.1 mm and 1.4-1.6 mm, in males and females, respectively.

Colouration (after> 30 years in alcohol) (Fig. 38 ): Head light brown with the usual dark band between eye patches; collum light brown, margins darker; Prozonae dark brown, becoming greyish on more posterior rings, with numerous lighter spots, dorsally with a blackish transverse stripe; metazonae anteriorly dark brown, lighter at hind margins; dorsum without axial line; whole body lighter on ventral side; pre-anal ring dark brown, paraprocts lighter.

External structures: Eye patches in adults consisting of 30-35 ommatidia arranged in easily countable vertical rows. Vertigial, supralabral, and labral setae: two, four, and 15, respectively. Antennae (in Fig. 38A ) ca. 1.5 × as long as head in males and 1.3 × in females; antennomere 5> 2> 4> 3> 6. Gnathochilarium with promentum almost separating lamellae linguales halfway, each latter with three or four setae in a longitudinal row. Collum smooth, with only several small, shallow, oval grooves near posterolateral corners.

Body rings very gently vaulted. Prozonae with scattered, short and shallow, mostly parallel longitudinal striae. Metazonae relatively deeply striated, n Schub = 6 or 7 (males) and 7 or 8 (females); metazonal setae ca. 3/4 metazonal length in most rings, this ratio becoming 1:1 in caudalmost rings. Ozopores placed right in pro-metazonal suture in first several rings, gradually taking a more posterior position to ~ 1/2 of their diameter behind suture in caudalmost rings; sutures gently sinuous in front of ozopores in only some rings. Tarsus of mid-body legs 1.3-1.5 × as long as tibia and 3.5-5 × as long as apical claw.

Telson (Fig. 38C ): Epiproct very long, ending in a pointed hyaline tip turned slightly to considerably ventrad, surpassing the longest paraproctal setae in males, just reaching their level in females. Hypoproct (Fig. 39A ) relatively small, tridentate in males, with the teeth protruding behind rear contour of paraprocts; rounded, completely concealed under paraprocts in females; ventral surface with six submarginal setae. Paraprocts sparsely to moderately densely setose, without distinct rows of shorter setae along caudal margins.

Male sexual characters: Mandibular stipites (in Fig. 38B ) considerably expanded, protruding mostly anteriad, forming a broadly rounded anterior corner. Leg pair 1 compact rounded hooks, somewhat turned against one another. Leg pair 2 and several following pairs (Fig. 39B ) with crested adhesive pads, and with a small weakly pronounced bump proximally on femur (black arrow); tibial pads reduced posteriad, but still present until last leg pair, postfemoral ones completely disappearing in last several pairs. Pleurotergum 7 ventrally forming shovel-like lobes (Fig. 39C ) originating from the zone around pro-metazonal suture, protruding mostly ventrad, completely concealing opisthomeres from lateral view. Penis (Fig. 39D ) antero-caudally strongly compressed, with diverging apical lobes; terminal lamellae not differentiated.

Gonopods (Figs 39G-F , 40A-E ): In situ mostly concealed in gonopodal sinus, only apical part of promeres visible, approximately reaching the level of pleurotergal protrusions of pleurotergum 7, opisthomeres fully concealed between promeres and pleurotergal protrusions. Promere (Fig. 40A, p in Fig. 39E ) slightly higher than opisthomere, mesal margin mostly straight, lateral margin parallel to the former in proximal section, distally slanting towards a narrowly rounded apex; caudal surface with a short, strongly pronounced, median ridge, a very short and narrow median groove, and a rounded, micro-squamous, distomesal lobe directed caudad; flagellum slightly longer than height of promere. Opisthomere (Figs 39G-F , 40B-E ) relatively slender; basoposterior process weakly pronounced, ending in a tapering apical outgrowth with its tip turned anteriad; anterior process shaped as an elongated lobe running parallel to CBO, distally forked into two fine, pointed tips: a shorter, proximal one, and a longer, distal one, the former with a minute lamella at base; mesomeroidal lobe rather weakly pronounced, ending in an apicolateral part with slightly jagged edge bent anteriad; mesal side with a broad and deep anteromesal sinus, and (apparently) without a lobe at base; solenomere unipartite, straight, apically hollow; a row of rather small spiniform filaments along proximal section of flagellum channel.

Female sexual characters: Leg pairs 1 and 2 somewhat thicker than, and ca. as long as, following legs. Vulva (Fig. 39H ) relatively elongated; bursa symmetrical, with a strongly obtuse postero-apical margin; side sclerites apically ending up in small hyaline protrusions; operculum significantly higher than bursa, distally thickened and bent somewhat anteriad, with a rounded apical margin, caudal surface laterally ending up with two pointed hyaline protrusions; whole bursa sparsely setose, operculum with only several setae in distal part. Receptaculum seminis consisting of a short finger-shaped central tube, and a mostly straight posterior tube of same gauge, ending in a medium-size ovoid posterior ampulla.

Remarks.

As already mentioned under the Remarks section referring to Omobrachyiulus sevangensis comb. nov., Lohmander (1936) emphasised the peculiar gonopod morphology of that species to justify the erection of the monotypic subgenus Omobrachyiulus Armeniobrachyiulus of the genus Megaphyllum ( Chromatoiulus auctt.) in that same paper. O. kvavadzei sp. nov., despite sharing obvious gonopod similarities with O. sevangensis comb. nov., differs in having a more vertically developed mesomeroidal lobe and only partly lamellar anterior process of the opisthomere, which sets it closer to the “typical” members of Omobrachyiulus . For that reason, we prefer to refrain from the usage of the subgenus Omobrachyiulus Armeniobrachyiulus , and treat O. sevangensis and its three most similar congeners under the Omobrachyiulus sevangensis species group.

General distribution.

LECA.

Figures

Figure 38. Omobrachyiulus kvavadzei sp. nov., ♂ holotype (A) and ♂ paratype from near mouth of Khekpara River, AR Ajara, Georgia (ZMUM) (B, C) A habitus B head and body rings 1 - 4 C telson, lateral views. Not to scale.

Figure 39. Omobrachyiulus kvavadzei sp. nov., ♂ (A-F) and ♀ (H) paratypes from near mouth of Khekpara River, AR Ajara, Georgia, and ♂ paratype from Zeraboseli, AR Ajara, Georgia (ZMUM) (G) A hypoproct, ventral view B leg 7 C right flange of pleurotergum 7, ventro-lateral view D penis, caudal view E right gonopods, mesal view F right opisthomere, caudo-lateral view G distal part of right opisthomere, mesal view H right vulva, caudo-lateral view. Scale bars: 0.1 mm (A), 0.2 mm (B-H). Abbreviations: al apicolateral part of mesomeroidal lobe, ao apical outgrowth of basoposterior process, ct central tube, dt distal tip of anterior process f flagellum, op operculum, pa posterior ampulla, pt posterior tube s solenomere, sf spiniform filaments, si anteromesal sinus, tp proximal tip of anterior process.

Figure 40. Omobrachyiulus kvavadzei sp. nov., gonopods of ♂ paratype from near Chakhati, AR Ajara, Georgia (ZMUM) A left promere, caudal view (flagellum broken off near base) B right opisthomere (with flagellum in its channel), mesal view C left opisthomere, latero-caudal view D distal part of the same aspect E distal part of right opisthomere (with flagellum tip protruding out of its channel), mesal view. Scale bars: 0.1 mm (A-C), 0.05 mm (D, E). Abbreviations: al apicolateral part of mesomeroidal lobe, ao apical outgrowth of basoposterior process, ap anterior process, bpp basoposterior process, dml distomesal lobe, dt distal tip of anterior process, f flagellum, fc flagellum channel, g (supposed) gonocoxal gland, mg median groove, ml mesomeroidal lobe, mr median ridge, s solenomere, sf spiniform filaments, si anteromesal sinus, tp proximal tip of anterior process.