Skleroprotopus incisodentatus, 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. 10. Skleroprotopus incisodentatus sp. nov.

Figures 2 G , 13

Material examined.

Holotype male ( SCAU), Jiangxi Province, Shangrao City, Guangfeng County, Cave Lingjiu Dong , 28°27′54.12′′N 118 ° 20 ′ 39.79 ′′, 200 m, 29. IX. 2014, Huang Sunbin and Wang Xinhui leg. Paratypes: 2 males, 2 females ( SCAU), same data as for holotype ; 3 males, 7 females ( SCAU), same county, Cave Tiangui Yan , 28°27′31.44′′N 118°16′57.70′′E, 200 m, 28. IX. 2014 ; 1 male, 7 females ( SCAU), Zhejiang Province, Jiangshan City, Dachen County, Cave Wulong Dong , 28°48′35.83′′N 118°34′59.37′′E, 300 m, 28. IX. 2014, all Huang Sunbin and Wang Xinhui leg.

Diagnosis.

Differs from congeners mostly based on the following combination of characters: (1) telopoditomere 4 of male leg 1 with a small mesal hump (Fig. 13 D ); (2) penis slightly higher than coxae 2 (Fig. 13 C ); (3) male leg 7 with a very small coxal process, much lower than telopodite, which is made up of 4 segments and a claw (Fig. 13 F ); (4) anterior gonopod (Fig. 13 E, I ) with a very long coxal process carrying a narrow, lower, membranous lobe, distally with a vague indentation. — In addition, this new species differs from all other species analyzed in a> 8.0 % uncorrected p - distance of the COI barcoding gene.

Etymology.

The specific epithet refers to the distally vague indentation of a membranous lobe of anterior gonopod; adjective.

Description.

Length of both sexes ca 26.0–44.0 mm, 1.7–2.0 mm in diameter, body with 48–68 podous + 1–2 apodous rings + telson. Natural coloration (Fig. 2 G ) red brownish to purple brownish; generally yellow brownish in alcohol, prozona dark brownish. Antennae and legs yellow. Eye patches blackish, subtriangular, arranged in 6–8 irregular rows, altogether about 24–48 ommatidia per eye patch.

Head capsule smooth and hairless, eyes slightly bulged, epicranial suture well-defined. Labral margin with 2 + 2 supra-labral and 8 + 8 labral setae (Fig. 13 B ). Antennae long and slender, reaching behind to middle of ring 4 when stretched dorsally. In length, antennomeres 3> 2> 4 ≈ 5> 4> 6> 7> 1. Antennomeres 5 and 6 each with a distal corolla of sensilla basiconica. (Fig. 13 B ). Mandibular stipes well-rounded, with two small lobes in males, regularly rounded in females. Gnathochilarium with at least 5 setae on each lamella lingualis (ll); promentum (pr) short and lanceolate, anteriorly swollen in males (Fig. 13 B ), vs a narrow rhombic pr in females (Fig. 13 A ).

Collum with 11–14 lower striae laterally, but lowest 2 striae not reaching the anterior margin. Prozona with 2–3 irregular subtransverse striae and metazona with 16–25 longitudinal striae laterally. Suture dividing pro- and metazona very narrow, a regular comb. Ozopores starting with ring 6, lying mid-laterally on sides of metatergites.

Epiproct slightly protruding caudad, with 3 + 3 setae laterally. Paraprocts convex, 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. 13 D ) hypertrophied, 5 - segmented, strongly curved anteriad; coxa (cx) and telopoditomeres 1 and 2 (t 1, t 2) with some scattered long setae. Telopoditomere 3 (t 3) longest, about 1.5 × as long as telopoditomere 4 (t 4), t 4 irregularly shaped, subapically with a small mesal hump (h). Male leg-pair 2 (Fig. 13 C ) reduced in size; penis (pn) relatively thick, only slightly higher than coxae (cx), distal part with 3 long setae. Male leg-pair 7 (Fig. 13 F ) reduced, each leg with a 4 - segmented telopodite (te) and a claw, telopoditomere 2 (t 2) with a long seta subapically; coxal process (cp) small, median margin setose.

Anterior gonopods (Fig. 13 E, I ) with a very long coxal process (cp), bearing several short villi laterally, posteriorly carrying with a narrow, lower, membranous lobe (ml), outer margin of ml smooth, with a vague indentation distally. Flagellum (f) very long and slender, distally branched and villose. 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. 13 H ) branched distally, anterior branch smooth, with a pointed tip, posterior one densely setose.

Vulvae (Fig. 13 G ) as usual, with two parallel rows of short setae on anterior and posterior surfaces, operculum (op) with several long setae distally.

Remarks.

This species was collected from two caves in the same county in Jiangxi Province, about 6 km apart. However, both are only about 40–50 km away from the collection site / cave in Zhejiang Province. Based on the pigmented body, black eyes, as well as moderately long legs, S. incisodentatus sp. nov. is considered a troglophile.

Figures

Figure 2. Pictures of live animals, photos by Prof. Mingyi Tian from SCAU. A Skleroprotopus change sp. nov.; B Skleroprotopus megistus sp. nov.; C Skleroprotopus longissimus sp. nov.; D Skleroprotopus genjudi sp. nov.; E Skleroprotopus tiankeng sp. nov.; F Skleroprotopus laiyuanensis sp. nov.; G Skleroprotopus incisodentatus sp. nov.

Figure 13. Skleroprotopus incisodentatus sp. nov. . paratypes from Cave Lingjiu Dong. A, G female paratype; B – I male paratype. A, B gnathochilarium; C legs 2 with penis, posterior view; D legs 1, anterior view; E anterior gonopods, anterior view; F legs 7, anterior view; G vulvae, lateral view; H posterior gonopods, anterior view; I anterior gonopods, posterior view. Abbreviations: a 5, a 6, antennomeres 5, 6; cp, coxal process; cx, coxa; f, flagellum; h, hump; 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.