Acanthophorella valerii Antić, 2023

Antić, Dragan, Šević, Mirko, Barjadze, Shalva & Makarov, Slobodan, 2023, Review of the genus Acanthophorella Antić & Makarov, 2016 (Diplopoda, Chordeumatida, Anthroleucosomatidae), with descriptions of three new species from the Caucasus, European Journal of Taxonomy 908, pp. 39-76 : 56-64

Acanthophorella valerii Antić sp. nov.

urn:lsid:zoobank.org:act:B24D09EE-1BDA-4F40-A853-F3280C49DD7B

Figs 1G–H , 11–16 , 21F , 22

Diagnosis

Distinguished from congeners and members of the genus Pseudoflagellophorella , except for A. barjadzei and A. devi sp. nov., by a whitish and unpigmented body (vs pigmented body in others). From both latter it differs by the presence of 10–13 black ommatidia (vs a mainly smaller number of transparent to pale brownish ommatidia in A. barjadzei and A. devi ). Additionally, from A. barjadzei and A. devi . Acanthophorella valerii sp. nov. differs in the general shape of the anterior gonopods, the angiocoxites of the posterior gonopods being short, poorly developed (vs angiocoxites well-developed and strong in A. barjadzei and A. devi ), the coxal processes of leg-pair 7 without lateral lobe (vs lateral lobe present in A. barjadzei and A. devi ) and leg-pair 10 with well-developed coxal processes (vs leg-pair 10 without or with strongly reduced coxal protrusions only in A. devi , or with strong protrusions in A. barjadzei ).

Etymology

The new species is named after Valeri Barbakadze, a Georgian speleologist, cave diver and rescuer. He was an excellent and safe driver, guide and photographer of the cave interior, landscapes and our work during the 2022 expedition to Georgian caves. An interesting thing that gives this name a special charm happened right in front of the type locality of this species, the Usholta Cave. At one point, all members of the expedition came out of the cave, except Valeri, who was still photographing the interior. After a while, the youngest member of the expedition, Luka Barjadze, became worried about Valeri (or most likely about who would drive us back) and started calling him and shouting ‘Valeriiiii’. As there is a river running through the cave, Valeri could not hear the call, so the youngster persistently repeated ‘Valeriiiii... Valeriiiii’. ‘Valeriiiii’ could (still) be heard hundreds of metres from the cave entrance. The epithet, a name in the genitive case, is a patronym.

Material examined (2 ♂♂, 1 ♀, 8 juvs)

Holotype GEORGIA • ♂; Racha, Oni Municipality, Racha karst massif , Usholta village , Usholta Cave ; 1772 m a.s.l.; 25 Jul. 2022; D. Antić, E. Kiria, L. Shavadze and S. Barjadze leg.; NHMW MY10366 .

Paratypes GEORGIA • 1 ♂, 1 ♀ (used for SEM); same collection data as for holotype; IZB • 8 juvs; same collection data as for holotype; IZISU .

Description

SIZE AND NUMBER OF BODY RINGS. Body with 31 rings (including telson). Holotype male 15 mm long, vertical diameter of the largest ring 1.10 mm. Paratype male 14 mm long, vertical diameter of the largest ring 1.0 mm. Paratype female 15 mm long, vertical diameter of the largest ring 1.25 mm.

COLORATION ( Figs 1G–H , 11 ). Living animals dirty white, with white legs and antennae and black ommatidia.

HEAD ( Figs 11B–D , 12A–D ). Setose, roundly convex in females, in males with labral and frontal surfaces flat with convexity between and 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 8+8 setae. Stipites with ca 30 setae each. Antennae 2.6 mm long in paratype male. Length of antennomeres (in mm): I (0.1), II (0.25), III (0.74), IV (0.34), V (0.7), VI (0.21), VII (0.21) and VIII (0.05). Length/breadth ratios of antennomeres I–VII: I (1), II (1.7), III (6.7), IV (3.1), V (4.6), VI (1.4) and VII (1.8). Antennomeres II, IV, V, VI and VII with one, three, one, four and one long sensillum trichoideum, respectively. Antennomere 7 with one rather bacilliform sensillum (sensillum basiconicum?) curved distad, located below sensillum trichodeum ( Fig. 12C ). Lateral to antennal sockets, a group of papilliform outgrowths present. Number of ommatidia: 10–13 in 3–4 rows, arranged in elongated triangles ( Figs 11B–C , 12B, D ).

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

BODY RINGS ( Figs 11A, E–F , 12E–H ). With well-developed lateral keels, anterior margins rounded in dorsal view. Macrochaetae long and rather trichoid ( Fig. 12F ). CIX (ring 15) = 0.6; MIX (ring 15) ~ 1.6; PIX (ring 15) = 0.5; MA (ring 15) ~ 100°.

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 1G–H , 13B–D ). Gonopores mesally on coxae 2 ( Fig. 13B ). Leg-pairs 3–7 enlarged, especially leg-pairs 3, 4 and 7 ( Fig. 1G, H ). Leg-pairs 3 and 4 very thick, 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. Leg-pair 6 without peculiarities. Leg-pair 7 robust; coxae with wide, well-developed, flattened posterior processes, covered with long setae anteriorly and each with a mesal tooth ( Fig. 13C ). Leg-pair 10 with coxal glands and well-developed coxal processes oriented posteriad ( Fig. 13D ). Leg-pair 11 with coxal glands, no other peculiarities.

ANTERIOR GONOPODS ( Figs 13E , 14A–F , 15A–C , 21F ). Gonopodal sternum (s) wide, medially with a moderately developed and poorly fimbriate lamella (sl) on anterior side and a bilobed membranous part above. Angiocoxites (a) consisting of a medial part (mp), lateral lamellae (ll) and a synangiocoxal base with anterior processes (ap). Medial parts well-developed, ear-shaped, divided, but appressed to each other, shieldlike, distomesal margins strongly denticulate posteriorly; angiocoxites posteroproximally with a pair of tufts (tf) with longer and shorter hairlike outgrowths, with a spinelike process and a rounded lobe, covered by spiculiform outgrowths. Lateral lamellae low, wide and spoon-shaped in lateral view, with denticulate margins. Anterior processes (ap) tapering distad, acuminate, twice as high as lateral lamellae. A syncoxal vesicle (cv) present posteriorly.

POSTERIOR GONOPODS ( Figs 13F , 15D–E ). Gonopodal sternum (s) wide, well-developed. Angiocoxites (a) positioned posteriorly, poorly developed, short, much smaller than colpocoxties (c). Colpocoxites strongly developed, tapering in anterior and posterior views, but wide and spoon-shaped in lateral view; margins denticulate. Telopodites (t) small, rounded, placed posterolaterally.

LEG PAIR 2 IN FEMALES ( Fig. 13A ). Coxae with poorly developed distomesal protrusions covered with a few small tubercles and setae.

VULVAE ( Figs 14G–I , 15F–G ). Rounded, as long as wide. Operculum (o) well-developed, bilobed, lateral lobe with three, mesal with two setae. Bursa (b) with strongly thickened anteroproximal lips on which the operculum rests. Lateral valve with a rounded lobe carrying six setae, mesal valve with a rounded lobe carrying five setae with an additional seta below the lobe.

Locality and ecology

The Usholta Cave, formed in the Lower Cretaceous limestones, is characterised by 2200 m of explored channels, with a permanent water flow in the main channel ( Tatashidze et al. 2009). This part is poor in speleothems and is mainly characterised by a sandy and gravelly bottom. The deeper, side channels without permanent water flow are rich in speleothems and a clay substrate.

Although many juveniles (only eight were collected) were observed in the dark and damp parts of the cave in all parts explored, exclusively on or in dead wood, only three living adults were found and all three under the stones in the main channel on the banks of the stream. Interestingly, about a dozen dead adults were also found under the stones in the same main channel ( Fig. 16 ). This could mean that at the time of our visit (end of July) the life cycle of the adults was coming to an end and that it is possible that for some reason the adults go under the stones before they die, considering that all of them (both live and dead) were found exclusively under the stones near the stream.

Until now, this cave was very poorly studied in terms of its fauna, as only two common Palaearctic insect species from the families Formicidae Latreille, 1809 and Geometridae Leach, 1815 were recorded ( Barjadze et al. 2015). Besides A. valerii sp. nov., two other troglobionts from the genera Neobisium Chamberlin, 1930 ( Pseudoscorpiones ) and Inotrechus Dolzhanski & Ljovuschkin, 1989 ( Coleoptera ) were found in the cave, as well as the troglophiles Micropterna clavata Martynov, 1916 and Stenophylax permistus McLachlan, 1895 (both Trichoptera ) and a species from the genus Plutomurus Yosii, 1956 ( Collembola; one juvenile can be spotted in Fig. 1G ) (unpubl. data).

Based on the ecology, as well as the unpigmented body, this species can be considered as a neotroglobiont.

Distribution

A Georgian endemic known only from its type locality, Usholta Cave, near Usholta village (Oni Municipality) ( Fig. 22 , orange circle).

Figures

Fig. 1. Troglobiotic members of the genus Acanthophorella Antić & Makarov, 2016 in situ. A–B. Acanthophorella barjadzei Antić & Makarov, 2016, ♂ from Nikortsminda Sakinule Cave. C–D. Acanthophorella barjadzei Antić & Makarov, 2016, ♂ from Muradi Cave. E–F. Acanthophorella devi Antić sp. nov., types, ♂♂. G–H. Acanthophorella valerii Antić sp. nov., holotype, ♂ (NHMW MY10366). Photos by Dragan Antić.

Fig. 11. Acanthophorella valeriiAntić sp. nov. A, C, E, F. Holotype, ♂ (NHMW MY10366). B. Paratype, ♀ (IZB). D. Paratype, ♂ (IZB). A. Habitus, lateral view. B. Head, lateral view. C. Head, lateral view. D. Anterior part of the body, anterior and ventral view. E. Midbody rings, lateral view. F. Rings 15 and 16, dorsal view. Scale bars: A, D–F = 1 mm; B–C = 0.5 mm.

Fig. 12. Acanthophorella valerii Antić sp. nov., paratype, ♂ (IZB). A. Labrum, anterior view. B. Left field with ommatidia and organ of Tömösvary, lateral view. C. Left antennomere 7, showing bacilliform sensillum. D. Left field with ommatidia, anterior view. E. Ring 15, dorsal view. F. Right interior macrochaeta of ring 15, dorsal view. G. Rings 14–16, dorsolateral view. H. Rings 14 and 15, anterior view. Scale bars: A–B, F = 0.1 mm; C–D = 0.01 mm; E = 0.2 mm; G, H = 0.5 mm.

Fig. 13. Acanthophorella valerii Antić sp. nov. A. Paratype, ♀ (IZB). B–F. Paratype, ♂ (IZB). A. Legpair 2, anterior view.B. Leg-pair 2, posterior view.C. Leg-pair 7, posterior view.D. Leg-pair 10, anterior view. E. Anterior gonopods, anterior view. F. Posterior gonopods, posterior view. Scale bars = 0.2 mm.

Fig. 14. Acanthophorella valerii Antić sp. nov. A–F. Paratype, ♂ (IZB). G–I. Paratype, ♀ (IZB). A. Anterior gonopods, anterior view. B. Anterior gonopods, posterodistal view. C. Anterior gonopods, left tuft, posterodistal view. D. Anterior gonopods, lateral view. E. Anterior gonopods, distal view. F. Anterior gonopods, laterodistal view. G. Vulvae, distal view. H. Left vulvae, lateral view. I. Left vulvae, anterior view. Abbreviations: a = angiocoxite; ap = anterior process; b = bursa; cv = syncoxal vesicle; ll = lateral lamella; mp = medial part; o = operculum; s = sternum; sa = synangiocoxal base; sl = sternal lamella; tf = angiocoxal tuft. Scale bars: A–B, D–I = 0.1 mm; C = 0.02 mm.

Fig. 15. Acanthophorella valerii Antić sp. nov. A–E. Paratype, ♂ (IZB). F–G. Paratype ♀ (IZB). A. Anterior gonopods, anterior view. B. Anterior gonopods, posterior view. C. Anterior gonopods, lateral view. D. Posterior gonopods, posterior view. E. Left posterior gonopod, lateral view. F. Left vulva, distal view. G. Left vulva, lateral view. Abbreviations: a = angiocoxite; ap = anterior process; b = bursa; c = colpocoxite; cv = syncoxal vesicle; ll = lateral lamella; mp = medial part; o = operculum; s = sternum; sa = synangiocoxal base; sl = sternal lamella; t = telopodite; tf = angiocoxal tuft. Drawings by DA (A–E) and MŠ (F–G). Scale bars = 0.2 mm.

Fig. 16. Dead adult specimen of Acanthophorella valerii Antić sp. nov. under the stone on the bank of the cave stream. Photo by Dragan Antić.

Fig. 21. Anterior gonopods in the genera Acanthophorella Antić & Makarov, 2016 and PseudoflagellophorellaAntić & Makarov, 2016, anterior views. A. A. auritaAntić sp. nov. B. A. barjadzei Antić & Makarov, 2016. C. A. chegemi Antić & Makarov, 2016. D. A. devi Antić sp. nov. E. A. irystoni Antić & Makarov, 2016. F. A. valerii Antić sp. nov. G. P. eskovi Antić & Makarov, 2016. H. P. mirabilis Antić & Makarov, 2016. I. P. papilioformis Antić & Makarov, 2016. B–C, E, G–I after Antić & Makarov (2016). Scale bar = 0.2 mm.

Fig. 22. Distribution of the genus Acanthophorella Antić & Makarov, 2016.