Acanthophorella eto, Antić & Margalitadze & Šević, 2025

Acanthophorella eto View in CoL sp. nov.

Figs 4–6 View FIGURE 4 View FIGURE 5 View FIGURE 6 , 16F 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. gaumarjos sp. nov., A. valerii and A. spinicoxa sp. nov. by the presence of transparent ommatidia (vs. black ommatidia in A. gaumarjos sp. nov., A. valerii and A. spinicoxa sp. nov.). A. eto sp. nov. differs from the other troglobiotic species by the presence of subquadrangular processes on coxae 7 without teeth or lobes (vs. presence of small, acuminate, mesal teeth in A. barjadzei , the presence of small, mesal lobes in A. didi sp. nov. or the presence of subtriangular processes in A. devi ).

Name. The new species is named in honour of a friend and colleague Eter (Eto) Maghradze, a Georgian biospeleologist and the first collector of this new species. Noun in apposition.

Material examined

Holotype: GEORGIA ● ♂; Tskaltubo Municipality , Sataplia-Tskaltubo karst massif, Melouri Cave; 42°23’14”N 42°37’41”E; 418 m a.s.l.; 12 November 2022; E. Maghradze leg.; NHMW-MY10636. GoogleMaps

Paratypes: GEORGIA ● 2 ♀♀, 2 juveniles; same data as for holotype; NHMW-MY10637 GoogleMaps ● 1 juvenile; same locality and collector but 13 May 2018; IZISU GoogleMaps ● 2 ♂♂ (one fragmented with only posterior gonopods); same locality and collector but 12 May 2019; IZB GoogleMaps ● 1 ♀, 2 juveniles; same locality and collector but 1 February 2020; IZB GoogleMaps ● 1 juvenile; same locality and collector but 3 March 2020; IZISU GoogleMaps ● 2 ♂♂; same locality but 22 July 2024; N. Modebadze, L. Shavadze and A. Margalitadze leg.; IZISU GoogleMaps .

Additional material: GEORGIA ● 1 ♂, 3 ♀♀; Tskaltubo Municipality, Sataplia-Tskaltubo karst massif, Imereti, Prometheus Cave; 42°22’36”N 42°36’01”E; 178 m a.s.l.; 16 March 2018; E. Maghradze leg.; IZB GoogleMaps ● 1 ♂, 2 ♀♀, 3 juveniles; same collection data as for preceding; IZISU GoogleMaps ● 1 ♂, 1 ♀; same locality and collector but 13 May 2018; IZISU GoogleMaps .

Description

Number of body segments and size. Body with 31 segments (including collum and telson). Holotype male 14.3 mm long, vertical diameter of the largest segment 1.1 mm. Paratype males 14.2–14.9 mm long, vertical diameter of the largest segment 1.1 mm. Paratype females 15.8–16.9 mm long, vertical diameter of the largest segment 1.2–1.3 mm, respectively. Non-type males 15–15.6 mm vertical diameter of the largest segment 1.2 mm. Non-type females 14.5–16.5 mm long, vertical diameter of the largest segment 1.1–1.3 mm, respectively.

Coloration ( Fig. 4 View FIGURE 4 ). Living animals white.

Head ( Fig. 4C, D View FIGURE 4 ). Densely setose, roundly convex in females, in males with labral and frontal surfaces flat with a convexity between and with a pair of lateral lobes, each below antennal sockets. Labrum with three medial teeth and 5+5 labral and 2+2 supralabral setae. Promentum triangular, with one distal setae. Lamellae linguales with 9+8 setae. Stipites with ca 30 setae each. Antennae 2.7 mm long in holotype male. Length of antennomeres (in mm): I (0.14), II (0.26), III (0.75), IV (0.36), V (0.70), VI (0.22), VII (0.20) and VIII (0.07). Length/breadth ratios of antennomeres I–VII: I (1), II (1.7), III (6.3), IV (3.0), V (5.8), VI (1.4) and VII (1.4). 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. Ommatidia apparently absent, but there are 2–4 small, transparent and faintly visible corneas.

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

Body segments ( Fig. 4 View FIGURE 4 ). With well-developed lateral keels, anterior margins rounded in dorsal view.Macrochaetae very 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 4A, C View FIGURE 4 , 5A–G View FIGURE 5 ). Gonopores mesally on coxae 2 ( Fig. 5A View FIGURE 5 ). Leg-pairs 3–7 enlarged, especially leg-pairs 3, 4 and 7 ( Fig. 4A, C View FIGURE 4 ). Leg-pairs 3 and 4 very thick ( Fig. 5B, C View FIGURE 5 ), 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. 5D View FIGURE 5 ). Leg-pair 6 with a small proximal lateral protrusion on prefemora; without other peculiarities ( Fig. 5E View FIGURE 5 ). Leg-pair 7 robust; coxae with wide, well-developed, flattened and rectangular posterior processes, covered with long setae anteriomesally ( Fig. 5F View FIGURE 5 ). Leg-pair 10 with coxal glands and small, subtriangular coxal processes oriented posteriad; prefemora with distoventral thickening ( Fig. 5G View FIGURE 5 ). Leg-pair 11 with coxal glands, no other peculiarities.

Anterior gonopods ( Figs 5H View FIGURE 5 , 6A–C View FIGURE 6 , 16F View FIGURE 16 ). Gonopodal sternum (s) wide, medially with a moderately developed and fimbriate lamella (sl) with medial lobe, 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 in proximal half, shieldlike, distally subquadrangular, lateral margins folded posteriad; angiocoxites posteroproximally with a pair of tufts (tf) including lobes with spiculiform outgrowths and long hairs. Lateral lamellae well developed, high, curved laterad, and oblong in lateral view. Synangiocoxal base with a pair of anterior, mesal lobes (lo); anterior processes somewhat sigmoid, tapering distad, acuminate, as high as medial parts and completely visible in anterior view. Syncoxal vesicle (cv) present posteriorly.

Posterior gonopods ( Figs 5I View FIGURE 5 , 6D View FIGURE 6 ). Gonopodal sternum (s) wide, well developed. Angiocoxites (a) positioned posteriorly, slender, tapering, curved slightly anterolaterad, slightly longer than colpocoxites (c). Colpocoxites in anterior and posterior views oblong, almost the same width throughout their height; fused with basal half of angiocoxites. Telopodites (t) small, rounded, placed posteriolaterally.

Leg pair 2 in females. Coxae with poorly developed protrusions covered with few nipple like tubercles and setae that also spread onto the first podomere.

Vulvae ( Fig. 6E–G View FIGURE 6 ). As wide as long. Operculum (o) well developed, bilobed with 5+4 and 1+1 setae in two rows, anterior (1+1) setae longer. Bursa (b) with wide lip, anteriorly covering most of the bursa. Valves asymmetric but comparable in size, with groups of 14 setae on mesal and seven setae on lateral valve. Posteriorly with a somewhat wrinkeled lateral lobe.

Locality and ecology. The Melouri Cave is located in the Tskaltubo Municipality, north of the village of Kumistavi, in the Melouri area. The entrance opens at the bottom of a karst funnel located in a mixed coniferous forest. The investigated length of the cave is about 5 km, the air temperature varies between 12 and 13°C and there is a watercourse ( Tatashidze et al. 2009). The specimens were found about 400 metres from the entrance, under rocks and on walls near the water. A dozen troglophilic and troglobiotic arthropods are described or known in the cave. Only in the last five years have several interesting species been described or recorded from this cave, including four troglobionts: Leucogeorgia prometheus Antić & Reip, 2020 ( Diplopoda), Plusiocampa imereti Sendra & Barjadze, 2021 ( Diplura), Nemaspela melouri Martens, Maghradze & Barjadze, 2021 ( Opiliones ) and Centromerus georgicus Deltshev in Deltshev et al., 2023 ( Araneae ) (see Martens et al. 2021; Sendra et al. 2021; Deltshev et al. 2023). For a complete list of species from Melouri Cave, see Barjadze et al. (2019) (https://cbg.iliauni.edu.ge/en/caves/ show/148/melouri-cave).

Prometheus Cave is one of the most famous Georgian caves and one of the largest show caves in the region. The cave is 2900 metres in length ( Tatashidze et al. 2009), with a tourist section of about 1.2 km ( Tsikarishvili and Bolashvili 2013). It is also one of the richest caves in the Caucasus in terms of fauna. More than 40 invertebrate species are known from the cave ( Grosser et al. 2023). The specimens were collected in the Climbers’ hall, on the walls, dead trees and in the traps. In addition to the new species, the cave is inhabited by two other troglobiotic millipedes, Leucogeorgia prometheus and Trachysphaera fragilis Golovatch, 1976 . Besides L. prometheus , five new true cave-dwelling species have been described or reported from the cave in the last five years: Caucasogeyeria ignidona Grego & Palatov in Grego et al., 2020 and Imeretiopsis prometheus Grego & Palatov in Grego et al., 2020 (both Mollusca), Niphargus amirani Marin, 2020 ( Amphipoda ), Nemaspela prometheus Martens, Maghradze & Barjadze, 2021 ( Opiliones ) and Dina imeretiensis Grosser, Barjadze & Maghradze in Grosser et al., 2023 (Hirudinea) (see Antić and Reip 2020; Grego et al. 2020; Marin 2020; Martens et al. 2021; Grosser et al. 2023). For a complete list of species from Prometheus Cave , see Barjadze et al. (2019) (https://cbg.iliauni.edu.ge/en/caves/ show/74/prometheus-cave)

Distribution. A Georgian endemic, known so far only from the Melouri and Prometheus caves in the Sataplia-Tskaltubo karst massif ( Fig. 17 View FIGURE 17 ), and most probably from the nearby Satsurblia cave, where a juvenile was observed by DA in 2022.