Skleroprotopus laiyuanensis Chen, Zhao, Golovatch & Liu, 2024, sp. nov.

3.3. 13.Skleroprotopus laiyuanensissp. nov. Figures 2 F, 16 Material examined. Holotype male (SCAU), China, Fujian Province, Longyan City, Liancheng County, Laiyuan Town, Cave Chuqi Dong, 25°33′20′′N 116°59′51′′E, 950 m, 30. IV. 2018, Tian Mingyi and Cheng Jingli leg. Paratypes: 7 males, 11 females (SCAU), same data as for holotype; 2 males, 11 females (SCAU), same location, Cave Shiyan Dong, 29. IV. 2018; 3 males, 4 females (SCAU), same location, Cave Yanshang Dong, 30. IV. 2018, all Tian Mingyi and Cheng Jingli leg. Diagnosis. Differs from congeners mostly based on the following combination of characters: (1) telopoditomere 3 of male leg-pair 1 extremely long, longer than all other telopoditomeres combined (Fig. 16 D); (2) penis a little longer than coxae 2 (Fig. 16 E); (3) male leg-pair 7 with very large coxal processes, about 4 × as long as the telopodite (Fig. 16 F); (4) anterior gonopod (Fig. 16 H, I) with a very long coxal process carrying a narrow, lower, membranous lobe, outer margin distinctly microdentate; and an extremely slender flagellum. — In addition, this new species differs from all other species analyzed in a> 10.8 % uncorrected p - distance of the COI barcoding gene. Etymology. The species is named after its tye locality within the Laiyuan Karst Cave, which is the largest cave group known in Fujian Province, southeastern China; adjective. Description. Length of males ca 18.5–35.0 mm, 1.3–1.8 mm in diameter, body with 49–58 podous + 1 apodous rings + telson. Length of females ca 27.0–38.0 mm, 1.8 mm in diameter, body with 53–58 podous + 1 apodous rings + telson. Natural coloration (Fig. 2 F) yellowish, in alcohol marbled brownish or red brownish. Antennae and legs yellowish. Eye patches blackish, subtriangular, arranged in 4–6 irregular rows, altogether about 22–43 ommatidia per eye patch. Head capsule smooth and hairless, eyes slightly bulged, epicranial suture well-defined. Labral margin with 2 (3) + 2 (3) supra-labral and 12 + 12 labral setae. Antennae very long and slender, reaching behind to middle of ring 5 when stretched dorsally. Antennomeres: 3> 4> 2 ≈ 5> 6> 1> 7. Antennomeres 5 and 6 each with a distal corolla of sensilla basiconica (Fig. 16 C). Mandibular stipes well-rounded, with two small lobes in males, regularly rounded in females. Gnathochilarium with at least 6 setae on each lamella lingualis (ll); promentum (pr) heart-shaped at base, the remainder swollen and fusiform in males (Fig. 16 B), vs a narrow, oblong and rhomboid pr in females (Fig. 16 A). Collum with marbled brownish spots and 11 lower striae laterally, but lowest 2 striae not reaching the anterior margin. Prozona marbled, with 3–4 subtransverse striae and metazona with 20–23 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 7 + 7 setae at posterior margin. Paraprocts convex, medially with 3 + 3 setae. Hypoproct eye-shaped, with 1 + 1 setae. Legs medium-sized, about as long as midbody height. Male leg-pair 1 (Fig. 16 D) hypertrophied, 5 - segmented strongly curved anteriad; coxa (cx) and telopoditomeres 1 and 2 (t 1, t 2) with several long setae. Telopoditomere 3 (t 3) longest, longer than all other telopoditomeres combined. Telopoditomere 4 (t 4) irregularly shaped, medially with a few long setae. Male leg-pair 2 (Fig. 16 E) reduced in size and rather slender; penis (pn) slightly longer than coxae (cx), distal part with three long setae. Male leg-pair 7 (Fig. 16 F) strongly modified, with a very small 2 - segmented telopodite (te), telopoditomere 2 (t 2) larger, with a few long setae subapically; coxal process (cp) about 4.0 × as long as te, densely setose. Anterior gonopods (Fig. 16 H, I) with a very long coxal process (cp) bearing a short row of short villi in anterior view, posteriorly with a narrow and low membranous lobe (ml), outer margin of ml distinctly microdentate. Flagellum (f) very long and extremely slender, distally villose. Telopodite (te) about 2 / 3 as long as cp, densely setose apically and mesally. Posterior gonopods (Fig. 16 J) erect and slenderer, distally densely setose; anteriorly with a rather small pointed tip. Vulva (Fig. 16 G) as usual, with two parallel rows of short setae on both anterior and posterior surfaces. Operculum (op) subapically with three pairs of long setae, and two long distal setae on bursa. Remarks. This new species was found in several caves in Laiyuan Karst, which is the largest karst cave group found in eastern China (Fig. 17). Based on the unpigmented body and long antennae, S. laiyuanensis sp. nov. is rather to be considered as a troglobite.