Leucogeorgia caudata, Antić & Reip, 2020

Antić, Dragan Ž. & Reip, Hans S., 2020, The millipede genus Leucogeorgia Verhoeff, 1930 in the Caucasus, with descriptions of eleven new species, erection of a new monotypic genus and notes on the tribe Leucogeorgiini (Diplopoda: Julida: Julidae), European Journal of Taxonomy 713, pp. 1-106 : 58-63

Leucogeorgia caudata sp. nov.

urn:lsid:zoobank.org:act:301B3880-9D65-42A7-B2ED-FAC7304C326D

Figs 1B , 36–38 , 56–57

Diagnosis

This species belongs to the group of Leucogeorgia spp. with modified mouthparts and teeth on the mesomeral claw (vs teeth absent in L. longipes ). Leucogeorgia caudata sp. nov. clearly differs from all other congeners by having an epiproct with a very long and sharp caudal process, apically with a hyaline tip slightly curved upwards (vs absence of such a long and sharp process with a hyaline tip in all other congeners) and elongate antennae with the length 200% of the vertical diameter of the largest body ring (vs shorter antennae, ± 190% of the vertical diameter of the largest body ring in other species of Leucogeorgia with modified mouthparts).

Etymology

From the Latin ʻ caudata ʼ (= ʻtailedʼ), reflecting the presence of a long and sharp caudal process on the epiproct. Adjective in feminine gender.

Material examined

Holotype

ABKHAZIA – Gudauty District • ♂; Gumishkhinsky karst Massif , Novyi Afon , Novoafonskaya (= New Athos) Cave, Corallite Gallery ; 43.09° N, 40.81° E; 18–20 May 2016; S.A. Kapralov leg.; ZMUM.

Paratypes

ABKHAZIA – Gudauty District • 1 ♂, 1 ♀; same collection data as for holotype; ZMUM • 1 ♂, 1 ♀; same collection data as for holotype; IZB • 5 ♀♀; same collection data as for holotype but White Mountain ; 2 Jan. 2017; ZMUM .

Other material

ABKHAZIA – Sukhum District • 1 ♂, 2 ♀♀, 1 juv.; Gumishkhinskiy karst Massif , near Verkhnaia Eshera village , Adzaba Cave , 50–100 m from entrance; 43.07° N, 40.99° E; 14 Sep. 2014; I.S. Turbanov leg.; ZMUM .

Description

SIZE AND NUMBER OF BODY RINGS. Holotype male 20 mm long, vertical diameter of largest body ring 1.55 mm, body with 34 podous rings + 1 apodous ring + telson. Longer paratype male 31 mm long, vertical diameter of largest body ring 1.7 mm, body with 40 podous rings + 0 apodous ring + telson. Smaller paratype male body with 38 podous rings + 1 apodous ring + telson. Paratype females 19–25 mm long, vertical diameter of largest body ring 1.6–2 mm, body with 32–38 podous rings + 0–2 apodous rings + telson.

COLOUR ( Figs 1B , 36 ). Living animals with whitish head, legs and telson; due to thin and transparent cuticle, body looks blackish, with some greyish or blackish patterns lateroventrally. Yellowish white to yellowish brown or greyish white in alcohol.

HEAD ( Figs 36 B–D, 37C–E). Without ommatidia. Frontal setae absent. Labrum without labral teeth, with 4 supralabral setae and 26–30 labral setae. Gnathochilarium with a triangular promentum; lamellae linguales with 1+1 long distal setae and 3+3 or 4+4 long proximal setae; stipites with 3+3 long distolateral setae; no other setae. Antennae 3.1 mm long in holotype male, their length 200% of vertical diameter of largest body ring. Lengths of antennomeres I–VIII (in mm): 0.11 (I), 0.57 (II), 0.71 (III), 0.58 (IV), 0.65 (V), 0.33 (VI), 0.1 (VII) and 0.05 (VIII). Length/width ratio of antennomeres I–VII: 0.8 (I), 2.8 (II), 3.5 (III), 3 (IV), 3.3 (V), 1.7 (VI) and 0.7 (VII). Antennomeres V and VI each with a terminal corolla of large sensilla basiconica bacilliformia; antennomere VII with a terminal corolla of small sensilla basiconica bacilliformia.

BODY RINGS ( Fig. 36E ). Entire metazonal area with longitudinal striations. Length of midbody setae ca 8% of vertical diameter of rings.

TELSON ( Fig. 36 G–H). Epiproct with a very long and sharp caudal process, apically with a hyaline tip slightly curved upwards; covered with dorsal and lateral setae. Paraprocts rounded, densely setose. Hypoproct subtrapezoid, in paratype female with 11 long setae.

LEGS IN MALES. First pair of legs modified, hook-shaped ( Figs 37 A–B, 38C), with three podomeres; coxa with one seta; prefemur with 5–6 setae; femora, postfemora and tibiotarsi coalesced; femur with 3–4 setae; postfemur with one seta. Tibiotarsal part with a small distal lobe and either with or without one seta. Tip slightly tuberculate. Postfemoral and tibial ventral pads developed on pregonopodal legs, then gradually disappearing on postgonopodal legs.

VENTRAL MARGIN OF MALE BODY RING 7 ( Fig. 36F ). Well-developed, low, rounded in lateral view.

PENES ( Fig. 38D ). Elongate, apically with two small subtriangular lobes.

GONOPODS ( Figs 37F , 38 A–B). Promere (p) long and slender, slightly curved anteriad, with a flagellum (f); apical part spatulate, with denticulate margins; basal half with two developed ridges. Mesomere (m) with a robust and denticulate mesomeral claw (mc); mesomeral lamella (ml) slightly convex, starting from mesal side of mc, distal margin serrate, posterior part finely fimbriate. Opisthomere (o) bipartite. Anterior branch of o with a solenomere (s) with a medium-sized tip, and a well-developed and fimbriate velum (v). Posterior branch of o in form of a shield-like protective lamella (pl). Mesomere and opisthomere connected basally with an accessory membrane (am).

Distribution

Known only from two neighbouring caves in the Gudauty and Sukhum districts of Abkhazia ( Fig. 57 , blue square).

Remarks

In the Novoafonskaya Cave, this species lives in sympatry with L. rediviva , which also has modified mouthparts.

Figures

Fig. 1. Leucogeorgia Verhoeff, 1930 species in situ. A. L. abchasica (Lohmander, 1936) comb. nov., ♂ from Abraskila Cave (photo: Ilya Turbanov). B. L. caudata sp. nov., type ♂ from Novoafonskaya Cave (photo: Olga Chervyatsova). C. L. gioi sp. nov., paratype ♀ (SMNG) (photo: Hans Reip). D. L. lobata sp. nov., specimens from Motena Cave (photo: Hans Reip). E. L. prometheus sp. nov., specimen from Prometheus Cave (photo: Hans Reip). F. L. profunda sp. nov., non-type ♀ from Veryovkina Cave (photo: Sergei Ivanov). G. L. turbanovi sp. nov., non-type ♂ from Krubera Cave (photo: Ilya Turbanov).

Fig. 36. Leucogeorgia caudata sp. nov., type ♂♂ from Novoafonskaya Cave. A. Holotype, habitus, lateral view (ZMUM). B. Holotype, head, lateral view. C. Paratype, head and anterior part of body, anterior view (IZB). D. Paratype, labrum, dorsal view (IZB). E. Holotype, midbody rings, lateral view. F. Paratype, body ring 7, lateral view (IZB). G. Paratype, telson, ventral view (IZB). H. Holotype, teslon, lateral view. Arrow indicates metazonal seta. Scale bars: A–C, E–F, H = 1 mm; D, G = 0.5 mm.

Fig. 37. Leucogeorgia caudata sp. nov., non-type ♂♂ from Adzaba Cave (ZMUM). A. Left leg 1, lateral view. B. Leg-pair 1, anterior view. C. Head, ventral view. D. Head, anterior view. E. Head, ventrolateral view. F. Right gonopods, mesal view. Abbreviations: am = accessory membrane; m = mesomere; mc = mesomeral claw; ml = mesomeral lamella; o = opisthomere; p = promere; pl = protective lamella; s = solenomere; v = velum. Scale bars: A = 0.05 mm; B, E–F = 0.1 mm; C–D = 0.2 mm.

Fig. 38. Leucogeorgia caudata sp. nov., paratype ♂ from Novoafonskaya Cave (IZB). A. Left gonopods, mesal view. B. Right gonopods, lateral view. C. Leg-pair 1, anterior view. D. Penes, posterior view. Scale bar: 0.3 mm.

Fig. 56. General distribution of the Caucasian leucogeorgiinines. The white dashed line hypothetically indicates the boundary between the northwestern and southeastern groups of species of the genus Leucogeorgia Verhoeff, 1930.

Fig. 57. Distribution of the northwestern group of the genus Leucogeorgia Verhoeff, 1930.