Leucogeorgia profunda, 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 : 67-71

publication ID	https://doi.org/ 10.5852/ejt.2020.713
publication LSID	lsid:zoobank.org:pub:A6CB58F5-1ECC-47F0-AA07-798844AF80A7
DOI	https://doi.org/10.5281/zenodo.4335812
persistent identifier	https://treatment.plazi.org/id/2FE7074E-8768-4D83-8C88-20A3F312A49F
taxon LSID	lsid:zoobank.org:act:2FE7074E-8768-4D83-8C88-20A3F312A49F
treatment provided by	Valdenar
scientific name	Leucogeorgia profunda
status	sp. nov.

Treatment

Leucogeorgia profunda View in CoL sp. nov.

urn:lsid:zoobank.org:act:2FE7074E-8768-4D83-8C88-20A3F312A49F

Figs 1F View Fig , 42–43 View Fig View Fig , 56–57 View Fig View Fig

Diagnosis

This species belongs to the group of Leucogeorgia spp. with modified mouthparts and teeth on the mesomeral claw (vs teeth absent from L. longipes ). Leucogeorgia profunda sp. nov. differs from L. rediviva , L. redivivoides sp. nov. and L. caudata sp. nov. by having a mesomeral claw that continues directly with the margin of the lamella, both parts being fully coalesced (vs mesomeral claw and lamella clearly connected mesally in L. rediviva , L. redivivoides sp. nov. and L. caudata sp. nov.). Leucogeorgia profunda sp. nov. differs from both L. mystax sp. nov. and L. turbanovi sp. nov. by having a more slender and elongate mesomeral claw (vs a more robust and shorter mesomeral claw in L. mystax sp. nov. and L. turbanovi sp. nov.). In addition to some other external characters, L. profunda sp. nov. differs from other congeners with modified mouthparts and teeth on the mesomeral claw by having a characteristic rounded extension of the hypoproct’s posterior margin in both sexes and shorter antennae, with the length 160% of the vertical diameter of the largest body ring (vs absence of such a rounded extension in congeners with modified mouthparts and teeth on the mesomeral claw and the presence of longer antennae, with the length Ẑ 170% of the vertical diameter of the largest body ring).

Etymology

From the Latin ʻ profunda ʼ (= ʻdeepʼ), referring to this being the world’s deepest-occurring julid species so far, found as deep as - 1650 m below the surface. Adjective in feminine gender.

Material examined

Holotype

ABKHAZIA – Gagry District • ♂; Gagra Mt Ridge, Arabika karst Massif , Ortobalagan Valley , Krubera (= Krubera-Voronya) Cave , - 1650 m deep; 43.41° N, 40.31° E; 20 Aug. 2015; I. Sofiniya and G.V. Samokhin leg.; ZMUM.

GoogleMaps

Paratype

ABKHAZIA – Gagry District • 1 ♂ same collection data as for holotype; ZMUM GoogleMaps .

Other material

ABKHAZIA – Gagry District • 1 ♀; Gagra Mt Ridge, Arabika karst Massif , Veryovkina Cave , - 1360 m deep; 43.41° N, 40.35° E; 1 Mar. 2018; P.E. Demidov leg.; IZB GoogleMaps • 1 ♀; Gagra Mt Ridge , Arabika karst Massif , Sarma Cave , - 1260 m deep, Transsib meander, cascade of cliffs under KSS; 43.38° N, 40.38° E; 15 Sep. 2011; P.V. Rudko leg.; ZMUM 1 ♀; GoogleMaps Gagra Mt Ridge , Arabika karst Massif , Sarma Cave , - 1370 m deep, well K25; 43.38° N, 40.38° E; 17 Sep. 2011; P.V. Rudko leg.; ZMUM GoogleMaps .

Description

SIZE AND NUMBER OF BODY RINGS. Holotype male 31 mm long, vertical diameter of largest body ring 1.9 mm, body with 43 podous rings + 0 apodous ring + telson. Paratype male 30 mm long, vertical diameter of largest body ring 1.9 mm, body with 42 podous rings + 0 apodous ring + telson. Non type females 32–44 mm long, vertical diameter of largest body ring 2.3–2.6 mm, body with 40–52 podous rings + 0–2 apodous rings + telson.

COLOUR ( Figs 1F View Fig , 42 View Fig ). Living animal with whitish head, anterior rings, legs and several posterior rings; due to thin and transparent cuticle, body looks blackish, with some greyish or blackish patterns. Yellowish white to yellowish brown or brown in alcohol.

HEAD ( Fig. 42B View Fig ). Without ommatidia. Frontal setae absent. Labrum without labral teeth (paratype male with three small labral teeth), with four supralabral setae and 30 labral setae in paratype male. Gnathochilarium with a triangular promentum; lamellae linguales with 1+1 long distal and 5+5 long proximal setae; stipites with 3+3 long distal setae; no other setae. Antennae 3 mm long in holotype male, their length ca 160% of vertical diameter of largest body ring. Lengths of antennomeres I–VIII (in mm): 0.17 (I), 0.6 (II), 0.67 (III), 0.58 (IV), 0.53 (V), 0.25 (VI), 0.15 (VII) and 0.05 (VIII). Length/width ratio of antennomeres I–VII: 0.7 (I), 2.7 (II), 3 (III), 2.6 (IV), 1.9 (V), 1 (VI) and 1 (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. 42D View Fig ). Entire metazonal area with longitudinal striations. Length of midbody setae ca 8% of vertical diameter of rings.

TELSON ( Fig. 42C, E View Fig ). Epiproct with a more or less long, robust and triangular caudal process, covered with dorsal and lateral setae. Paraprocts rounded, setose, mesal edges slightly bulging. Posterior margin of hypoproct with a characteristic rounded extension with two long apical setae.

LEGS IN MALES. First pair of legs modified, hook-shaped ( Fig. 43C View Fig ), with three podomeres; coxa with three setae; prefemur with 8–9 setae; femora, postfemora and tibiotarsi coalesced; femur with 4–5 setae; postfemur with one seta. Tip slightly tuberculated. Postfemoral and tibial ventral pads poorly developed on pregonopodal legs, then gradually disappearing on postgonopodal legs.

VENTRAL MARGIN OF MALE BODY RING 7 ( Fig. 42 View Fig F–G). Well-developed, low, more or less subquadrangular in lateral view.

PENES ( Fig. 43D View Fig ). Short, apically with two small subtriangular lobes.

GONOPODS ( Fig. 43 View Fig 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) proceeding directly to a mesomeral lamella (ml); ml poorly serrate, posterior part slightly 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 three deep caves in the Arabika karst Massif ( Fig. 57 View Fig , green square). The occurrence of this species in these three neighbouring caves has previously been recorded by Sidorov et al. (2014), Turbanov (2015) and Turbanov et al. (2018).

Remarks

This new species represents the deepest julid species ever to be encountered, as well as the second deepest-occurring millipede globally. Leucogeorgia profunda sp. nov. was found in the deep parts of three caves, viz., Sarma (- 1270 m and - 1370 m), Veryovkina (- 1360 m) and Krubera (- 1650 m). Only the chordeumatidan millipede, Heterocaucaseuma deprofundum Antić & Reboleira, 2018 , has been found deeper, i.e., in the Krubera Cave at depths of down to - 1980 m ( Antić et al. 2018a). Interestingly, Leucogeorgia profunda sp. nov. lives in the Krubera Cave sympatrically with L. turbanovi sp. nov., also with modified mouthparts, but apparently the two species occupy separate niches, since L. profunda sp. nov. has been found in the deep part of the cave (- 1650 m), while L. turbanovi sp. nov. occurs closer to the surface (- 100 m). It seems noteworthy that these three caves and their biotic communities are the deepest not only in the Caucasus, but also in the world ( Shelepin 2019).