Acanthophorella spinicoxa, Antić & Margalitadze & Šević, 2025

Acanthophorella spinicoxa View in CoL sp. nov.

Figs 11–14 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 , 16J View FIGURE 16 , 17 View FIGURE 17

Diagnosis. Troglobiotic species, which differs from the epigean, pigmented A. aurita , A. chegemi and A. irystoni by the depigmented body. The new species differs from the troglobiotic A. didi sp. nov., A. barjadzei , A. eto sp. nov. and A. devi by the presence of black ommatidia (vs. pale brownish or transparent ommatidia in A. didi sp. nov., A. barjadzei , A. eto sp. nov. and A. devi ). A. spinicoxa sp. nov. differs easily from troglobiotic A. gaumarjos sp. nov. and A. valerii by well-developed, lateral, triangular projections and distal pairs of processes strongly curved proximo-posteriad on medial parts of anterior gonopod angiocoxites and by the presence of spinelike processes on coxae 10 (vs. absence of triangular projections and distal pairs of processes on medial parts of anterior gonopods and absence of spinelike processes on coxae 10 in A. gaumarjos sp. nov. and A. valerii ).

Name. The new species is named after the presence of a well-developed, thornlike process on the coxa of leg pair 10. Noun in apposition.

Material examined

Holotype: GEORGIA ● ♂; Kharagauli municipality, Zemo Imereti plateau, Kozmani Cave ; 42°06’03”N 43°17’18”E; 652 m a.s.l.; 18 June 2023; D. Antić, A. Faille and E. Maghradze leg.; NHMW-MY10640. GoogleMaps

Paratypes: GEORGIA ● 1 ♂, 1 ♀, 2 juveniles; same data as for holotype; IZB GoogleMaps ● 1 ♀; same data as for holotype; NHMW-MY10641 GoogleMaps ● 1 ♀; same data as for holotype; SMNS GoogleMaps .

Additional material: GEORGIA ● 1 ♀, 7 juveniles; Chiatura Municipality, Zemo Imereti plateau, Kotia Cave ; 42°12’38”N 43°19’20”E; 749 m a.s.l.; 26 July 2022; D. Antić, L. Shavadze, E. Kiria and S. Barjadze leg.; IZB GoogleMaps ● 4 juveniles; same locality but 24 June 2023; A. Faille and D. Antić leg.; IZB GoogleMaps .

Description

Number of body segments and size. Body with 31 segments (including collum and telson). Holotype male 12.8 mm long, vertical diameter of the largest segment 0.95 mm. Paratype male 11.5 mm long, vertical diameter of the largest segment 0.95 mm. Paratype females 10.5–11.5 mm long, vertical diameter of the largest segment 1.0 mm.

Coloration ( Fig. 11 View FIGURE 11 ). Depigmented, dirty white, with some pigment remnants on head and anterior segments. Ommatidia blackish.

Head ( Fig. 11C View FIGURE 11 ). Setose, roundly convex in females, in males with labral and frontal surfaces flat with a convexity between and with a pair of poorly developed lateral lobes, each below antennal sockets. Labrum with three medial teeth and 4+4 labral and 2+2 supralabral setae. Promentum triangular, without setae. Lamellae linguales with 7+7 setae. Stipites with ca 25 setae each. Antennae 2.05 mm long in holotype male. Length of antennomeres (in mm): I (0.07), II (0.21), III (0.56), IV (0.30), V (0.54), VI (0.18), VII (0.15) and VIII (0.04). Length/breadth ratios of antennomeres I–VII: I (1), II (1.7), III (5.6), IV (3.0), V (4.0), VI (1.1) and VII (1.2). Antennomeres II, IV, V, VI and VII with one, three, one, four and one long sensillum trichoideum, respectively. Antennomere 6 with a distal corolla of longer sensilla basiconica.Antennomere 7 with one rather bacilliform sensillum (sensillum basiconicum?) curved distad, located below sensillum trichodeum. Lateral to antennal sockets, a group of papilliform outgrowths present. Number of ommatidia 13 in 4 rows in both holotype and paratype.

Collum. Narrower than head, with six macrochaetae as all body segments. Anterior edge semi-circular, posterior margin gently concave.

Body segments ( Fig. 11A, B, D–G View FIGURE 11 ). With well-developed lateral keels, almost rectangular in dorsal view. Macrochaetae long and rather trichoid.

Telson. Epiproct with a pair of spinnerets and 3+3 setae (1+1 paramedian, 2+2 marginal). Hypoproct with 1+1 distal setae. Paraprocts with 3+3 marginal setae in distal part.

Leg pairs 1 and 2. In both sexes with tarsal combs; femora, postfemora and tibiae with long and robust setae.

Male sexual characters ( Figs 11F View FIGURE 11 , 12 View FIGURE 12 ). Gonopores mesally on coxae 2 ( Fig. 12A View FIGURE 12 ). Leg-pairs 3–7 enlarged, especially leg-pairs 3, 4 and 7 ( Fig. 11F View FIGURE 11 ). Leg-pairs 3 and 4 very thick ( Fig. 12B, C View FIGURE 12 ), each with a proximal lateral protrusion on prefemora; prefemora and femora strong, rectangular; tarsi shorter and thicker compared to other legs; femora, postfemora and tibiae each with a distoventral pad. Leg-pair 5 with a proximal, anterior, triangular, coxal protrusion ( Fig. 12D View FIGURE 12 ). Leg-pair 6 with a small proximal lateral protrusion on prefemora; without other peculiarities ( Fig. 12E View FIGURE 12 ). Leg-pair 7 robust; coxae with wide, well-developed, flattened bilobed posterior processes, covered with long setae anteriorlly; mesal lobe strongly developed, lateral ones small ( Fig. 12F View FIGURE 12 ). Leg-pair 10 with coxal glands and well-developed, thornlike coxal processes oriented posteriad ( Fig. 12G View FIGURE 12 ). Leg-pair 11 with coxal glands, no other peculiarities.

Anterior gonopods ( Figs 13A, C View FIGURE 13 , 14A–C View FIGURE 14 ). Gonopodal sternum (s) wide, medially with a poorly developed and fimbriate lamella (sl) on anterior side. Angiocoxites (a) consisting of a medial part (mp), lateral lamellae (ll) and a synangiocoxal base (sa) with anterior processes (ap). Medial parts well developed, divided, but appressed to each other, shieldlike, with well-developed, lateral, triangular projections that covers subdistal parts of anterior processes in anterior view, distally with a pair of processes strongly curved proximoposteriad; angiocoxites posteroproximally with a pair of tufts (tf) including lobes with spiculiform outgrowths and short and long hairs. Lateral lamellae well developed and rather lanceolate in lateral view. Anterior processeses strongly developed, daggerlike, with two minute distal teeth, shorther than medial parts, slightly curved posteriad. Syncoxal vesicle (cv) present posteriorly.

Posterior gonopods ( Figs 13B, D View FIGURE 13 , 14D View FIGURE 14 ). Gonopodal sternum (s) wide, well developed. Angiocoxites (a) positioned posteriorly, poorly developed, considerably shorter than colpocoxites (c), mainly fused with c, free parts in form of small knobs. Colpocoxites well developed, in anterior and posterior views oblong, parallel or divergent to each other. Telopodites (t) strongly reduced, placed posteriolaterally.

Leg pair 2 in females. Coxae without setae or tubercules, with somewhat pronounced distal ridge.

Vulvae ( Fig. 14E–G View FIGURE 14 ). As long as wide. Operculum (o) well developed, strongly bilobed, with six (3+3) setae. Bursa (b) with wide, well-developed lips. Valves comparable in size, mesal valve with 14 setae, mesal side with numerous tubercules. Lateral valve with somewhat pronounced bulge; with eight setae.

Remarks. Antić et al. (2023) already wrote about the new Acanthophorella species from Kotia Cave. The observation was made on the basis of the gonopod pictures of a male that is considered lost in the IZISU collection. After comparing the pictures of the anterior and posterior gonopods of a male from Kotia Cave with the holotype from Kozmani Cave (see Fig. 13 View FIGURE 13 ), it seems to us that we are dealing with a conspecific taxon.

Locality and ecology. The Kotia and Kozmani caves are located in the Imereti region, Chiatura Municipality, Zemo Imereti plateau. The Kozmani Cave consists of three halls of different sizes, which are connected by small passages. The total length of the cave is 200 metres. It is a dry cave ( Tatashidze et al. 2009). The new species were found in dark and humid parts of the cave, crawling on the rocks or under stones. So far, only two species, both collembolans, have been described from this cave, Deuteraphorura kozmani Parimuchová, Barjadze & Kováč in Parimuchová et al., 2023 and Plutomurus kharagauliensis Barjadze, Kováč & Parimuchová in Barjadze et al., 2022 (see Barjadze et al. 2022; Parimuchová et al. 2023).

The Kotia Cave was formed in Cretaceous limestones and is mostly dry, except for a small underground stream at the end, and is 280 metres long ( Tatashidze et al. 2009). In addition to the new species, two other troglobiotic millipedes are known from the cave, Leucogeorgia gioi Antić & Reip, 2020 and the hygropetricolous Leucogeorgia longipes ( Antić and Reip 2020) . Only recently an opilion species Nemaspela kotia Martens, Maghradze & Barjadze, 2023 was described (Martens et al. 2023).

Distribution. A Georgian endemic, known so far only from the Kozmani and Kotia caves in the Zemo Imereti plateau ( Fig. 17 View FIGURE 17 ).