Skleroprotopus conicus, Chen & Zhao & Golovatch & Liu, 2024

Chen, Rong, Zhao, Yi, Golovatch, Sergei & Liu, Wei-Xin, 2024, Molecular phylogenetic and morphological studies reveal increased species diversity in the millipede genus Skleroprotopus Attems, 1901 in China (Julida: Mongoliulidae), Arthropod Systematics & Phylogeny 82, pp. 659-691 : 659-691

3.3. 12. Skleroprotopus conicus sp. nov.

Figures 3 E , 15

Material examined.

Holotype male ( SCAU), China, Zhejiang Province, Jinhua City, Wucheng District, Cave Xianpu Dong , 29°12′23.04′′N 119°38′5.47′′E, 650 m, 28. XII. 2018, Tian Mingyi, Cheng Jingli, Qin Zhuanghui and Chen Mengzhen leg. Paratypes: 8 males, 5 females ( SCAU), same data as for holotype ; 24 males, 34 females ( SCAU), China, Zhejiang Province, Jinhua City, Lanxi City, Cave Baiyun Dong , 29°12′50.19′′N 119°32′28.62′′E, 300 m, 28. XII. 2018, Tian Mingyi, Cheng Jingli, Qin Zhuanghui and Chen Mengzhen leg.

Diagnosis.

Differs from congeners mostly based on the following combination of characters: (1) telopoditomere 3 of male leg 1 longest, with a faint bulge in the middle (Fig. 15 D ); (2) penis very flat, much shorter than coxae 2 (Fig. 15 E ); (3) male leg 7 with a very small, cone-shaped coxal process and a basically normal telopodite (Fig. 15 F ); (4) anterior gonopod (Fig. 15 G, H ) with a very long coxal process carrying a narrow membranous lobe, outer margin distinctly serrate distally. — In addition, this new species differs from all other species analyzed in a> 10.0 % uncorrected p - distance of the COI barcoding gene.

Etymology.

The specific epithet refers to the male leg 7 with a rather small and cone-shaped coxal process; adjective.

Description.

Length of both sexes ca 27.0– 47.5 mm, width 1.8–2.0 mm in diameter, body with 55–68 podous + 1 apodous ring + telson. Coloration in alcohol uniformly brownish (Fig. 3 E ), prozona slightly red or dark brownish. Antennae and legs yellowish to light brown. Eye patches blackish, subtriangular, arranged in 6–14 irregular rows, altogether about 32–78 ommatidia per eye patch.

Head capsule smooth and hairless, vertex bulged, epicranial suture clearly concave. Labral margin with 2 + 2 supra-labral and 7 + 7 labral setae. Antennae long and slender, reaching behind to middle of ring 4 when stretched dorsally. In length, antennomeres 3> 4> 5> 2 ≈ 6> 7> 1. Antennomeres 5 and 6 each with a distal corolla of sensilla basiconica. Mandibular stipes well-rounded, with two small lobes in males, rounded in females. Gnathochilarium with at least 3 setae on each lamella lingualis (ll); promentum (pr) short and lanceolate, swollen anteriorly, tube-shaped in males (Fig. 15 A ), vs an oblong rhomboid pr in females (Fig. 15 B ).

Collum (Fig. 3 E ) with 5–7 lower striae laterally, but lowest 2 striae not reaching the anterior margin. Prozona with at least 10 irregularly scattered striae and metazona with 13–18 longitudinal striae laterally (Fig. 3 E ). Suture dividing pro- and metazona very narrow, a regular comb. Ozopores starting with ring 6, lying anteriorly on lateral sides of metatergites.

Epiproct slightly protruding caudad, posterior margin with 2 + 2 setae. Paraprocts convex, medially with 1 + 1 setae. Hypoproct eye-shaped, with 1 + 1 setae.

Legs medium-sized, about as long as midbody height. Male leg-pair 1 (Fig. 15 D ) hypertrophied, 5 - segmented, strongly curved anteriad; coxa (cx) and telopoditomeres 1 and 2 (t 1, t 2) with some long setae. Telopoditomere 3 (t 3) longest, with a faint bulge (b) in the middle. Telopoditomere 4 (t 4) irregularly shaped, with few setae medially. Male leg-pair 2 (Fig. 15 E ) reduced in size and stout; penis (pn) very flat, much shorter than coxae (cx), distal part with 6 long setae. Male leg-pair 7 (Fig. 15 F ) with a 4 - or 5 - segmented telopodite (te) sometimes asymmetrical (not including claw); coxal process (cp) rather small, cone-shaped, with few long setae apically.

Anterior gonopods (Fig. 15 G, H ) with a very long coxal process (cp) bearing a row of short villi in anterior view, posteriorly carrying with a narrow membranous lobe (ml), distal outer margin of ml distinctly serrate. Flagellum (f) very long and slender, with spikes at margin. Telopodite (te) about 3 / 4 as long as cp, with long setae both apically and mesally, laterobasally with a minute remnant (r) of a second podomere.

Posterior gonopods (Fig. 15 I ) erect, branched distally, anterior branch smooth, with a pointed tip, posterior one densely setose.

Vulva (Fig. 15 C ) as usual, with two parallel rows of short setae on anterior and posterior surfaces; operculum (op) with 2 long distal setae.

Remarks.

This species was collected from two caves in the same city, about 9 km apart. Based on the pigmented body, black eyes, as well as moderately long legs, S. conicus sp. nov. is rather to be considered as a troglophile.

Figures

Figure 3. Habitus of some Skleroprotopus species in lateral view. A Skleroprotopus penglai sp. nov.; B Skleroprotopus longiflagellatus sp. nov.; C Skleroprotopus tiankeng sp. nov.; D Skleroprotopus ampullaceus sp. nov.; E Skleroprotopus conicus sp. nov.; F Skleroprotopus yutiantianae sp. nov.; G Skleroprotopus multistriatus sp. nov.; H Skleroprotopus change sp. nov. Scale bars: 5.0 mm.

Figure 15. Skleroprotopus conicus sp. nov. . paratypes from Cave Xianpu Dong. A, D-I male paratype; B, C female paratype. A, B gnathochilarium; C right vulva, mesal view; D legs 1, anterior view; E legs 2 with penis, posterior view; F legs 7, anterior view; G anterior gonopods, anterior view; H anterior gonopods, posterior view; I posterior gonopods, anterior view. Abbreviations: b, bulge; cp, coxal process; cx, coxa; f, flagellum; ll, lamella lingualis; ml, membranous lobe; op, operculum; pn, penis; pr, promentum; r, remnant; t 1 – t 4, telopoditomeres 1–4; te, telopodite. Scale bars: 0.2 mm.