Glyphiulus xiniudong Zhao & Liu, 2022

Zhao, Yi, Guo, Wan-Ru, Golovatch, Sergei I. & Liu, Wei-Xin, 2022, Revision of the javanicus species group of the millipede genus Glyphiulus Gervais, 1847, with descriptions of five new species from China (Diplopoda, Spirostreptida, Cambalopsidae), ZooKeys 1108, pp. 89-118 : 89

Glyphiulus xiniudong Zhao & Liu sp. nov.

Figs 5D , 10 , 11

Type material.

Holotype ♂ (SCAU G78), China, Guangxi Zhuang Autonomous Region, Laibin City, Wuxuan County, Cave Xiniu Dong, 23°33'N, 109°32'55"E, 100 m alt., 2021-I-15, leg. Tian Mingyi, Liu Weixin & Zhao Yi. Paratypes: 4 ♂, 30 ♀ (SCAU G78), same data as the holotype.

Etymology.

To emphasise the provenance of this species from the “Xiniu” Cave, in Chinese meaning “rhinoceros”; noun in apposition.

Diagnosis.

Differs from congeners of the Glyphiulus formosus -group by the metazonae with an obvious, corrugate, carved texture and by the leg claw with a rather large accessory spine, coupled with a long subtriangular coxosternum of the anterior gonopod, the latter process being narrow and digitiform. Based on molecular evidence, G. xiniudong Zhao & Liu, sp. nov. differs from all other Glyphiulus species analysed in a> 14.7% uncorrected p-distance of the COI barcoding gene.

Description.

Length ca. 28.0-31.0 (♂) or 26.0-41.0 mm (♀), mid-body rings round in cross-section, their width and height similar, 1.1-1.3 (♂) or 1.2-1.8 mm (♀). Body with 42-54 (♂) or 45-64 (♀) podous + 0-3 apodous rings + telson. Colouration purple-brownish, legs almost transparent (Fig. 5D ).

Head surface smooth. Labrum with four teeth anteromedially. Ocellaria blackish, with 9-13 ommatidia arranged in 1-2 irregular linear rows (Figs 10B , 11A ). Antennae short, slightly clavate, reaching back to caudal margin of ring 2; in length, antennomeres 5> 3> 4 ≈ 2> 6> 1> 7. Antennomeres 5-7 each with a distodorsal field or corolla of bacilliform sensilla (sensory bacilli). Antennomere 7 with four sensory cones (Fig. 11B ). Gnathochilarium with a separate promentum, polytrichous on promentum and mentum, lamellae linguales each with 6-7 setae (Fig. 11B ). Mandible not dissected.

Collum: crests complete and evident; carinotaxy formula I-III+P+M (Figs 10A , 11A ). Following metaterga strongly crested; carinotaxy formula 2/2+I/i+3/3 (Fig. 10 ). Ozoporiferous tubercles very large, coniform. Prozonae delicately alveolate-areolate, fine longitudinal striations in front of stricture. Metazonae with an obvious, corrugate, carved texture (Fig. 10 ). Rings 2 and 3 with long pleural flaps.

Epiproct simple, caudal edge uneven, with an obvious central tubercle dorsally (Fig. 10E ). Paraprocts regularly convex, each with several irregular rows of setae. Hypoproct transversely bean-shaped, with 4+4 small setae (Fig. 10F ).

Legs short, about as long as mid-body height; claw with a relatively large accessory spine at base, about half as long as claw (Fig. 11C ). ♂ legs 1 very strongly reduced, represented by a sternum showing a pair of small, more slender, fused, paramedian, subunciform prongs directed forward, with about 7-9+7-9 long setae at base; flanked by strongly separated, rudimentary, 1-segmented leg vestiges, with some setae (Fig. 11D ). ♂ legs 2 slightly hypertrophied, coxae large; penes rather small, much shorter than coxae, oblong-subtrapeziform, each with three strong setae distolaterally (Fig. 11E ). ♂ legs 3 modified through coxae being especially slender and elongate. ♂ femora 6 and 7 normal, neither modifications.

Anterior gonopods (Fig. 11G ) with a long subtriangular coxosternum with about 9-11 microsetae near distal margin; apicomesal process of coxite very high, rather narrow and digitiform, modestly curved inwards. Telopodite very large, stout and coiled, 1-segmented, lateral in position, much higher than lateral corner of coxite, with a field of six microspinules at base and 6-7 strong setae apically.

Posterior gonopods (Figs 11H, I ) compact. Coxite subquadrate, with a circular field of about 10-15 basolateral microspinules in frontal view; with a field of 19 median microspinules and an apicolateral very strong and long seta in caudal view; apical and mesal parts of coxite with dense, strong and curved setae. Lamelliform lobe membranous, with a rather small, spine-like flagellum.

Vulvae very simple, bare, modestly emarginate medially (Fig. 11F ).

Remark.

In the absence of direct troglomorphic traits, this species can only be considered as troglophilic at most.

Figures

Figure 5. Pictures of live animals A G. sinuatoprocessus Zhao & Liu, sp. nov. from Cave Niubi Yan B G. scutatus Zhao & Liu, sp. nov. from Cave Bianfu Dong C G. portaliformis Zhao & Liu, sp. nov. from Cave Baiyan Dong D G. xiniudong Zhao & Liu, sp. nov. from Cave Xiniu Dong E G. conuliformis Zhao & Liu, sp. nov. from Cave Yanzi Dong.

Figure 10. Glyphiulus xiniudong Zhao & Liu, sp. nov., ♂ paratype A, B anterior body rings, dorsal and lateral views C, D mid-body rings, dorsal and lateral views, respectively E, F posterior body rings, dorsal and ventral views, respectively. Scale bars: 1 mm.

Figure 11. Glyphiulus xiniudong Zhao & Liu, sp. nov., ♂ paratype A head and collum B gnathochilarium and left antenna C mid-body leg and claw D leg 1, frontal view E penes F ♀ paratype, vulvae G anterior gonopods, caudal view H, J posterior gonopod, frontal view I, K posterior gonopod, caudal view. Scale bars: 0.5 mm (A, B), 0.2 mm (C-I), 0.1 mm (J, K).