Epanerchodus xiaoxiensis Li, Deng & Liu 2025, sp. nov.

Epanerchodus xiaoxiensis Li, Deng & Liu sp. nov. Figs 2, 3, 4, 5 Material examined. Holotype. China: • ♂ (JSUXiaoxi 03); Hunan Province, Xiangxi Tujia and Miao Autonomous Prefecture, Yongshun County, Xiaoxi National Nature Reserve, Jinji Cave; 28°46'48"N, 110°13'48"E, ca. 890 m a. s. l.; 12 August 2024, S. Li, H. J. Deng, Z. X. Liu, and Y. Tang leg. Paratypes. China: • 3 ♂♂, 3 ♀♀ (JSUXiaoxi 04 - JSUXiaoxi 09); same data as holotype. China: • 2 ♂♂, 4 ♀♀ (JSUXiaoxi 10 - JSUXiaoxi 15); same data as holotype; Hunan Province, Xiangxi Tujia and Miao Autonomous Prefecture, Yongshun County, Xiaoxi National Nature Reserve, Huangni Cave; 28°48'57"N, 110°14'19"E, ca. 31043 m a. s. l.; 4 May 2023, H. J. Deng, Q. J. Wu, D. Q. Xiang, and Z. X. Liu leg. China: • 5 ♂♂, 3 ♀♀ (JSUXiaoxi 16 - JSUXiaoxi 23); same data as holotype; Hunan Province, Zhangjiajie City, Cili County, Longwang Cave; 29°26'27"N, 110°43'41"E, ca. 380 m a. s. l.; 21 September 2024, S. Li, Y. Z. Zou, Z. X. Liu, and Y. Tang leg. Etymology. The specific name derives from the type locality, Xiaoxi National Nature Reserve. Adjective. Diagnosis. Adult males of E. xiaoxiensis sp. nov. are distinct from other Epanerchodus species based on the following combination of characters: (1) body smaller in size, length of body ca 11–13 mm (males), width of body ca 1.5–1.6 mm (males); (2) gonopodal prefemorite stout and short, about 1 / 3 as long as telopodite (Fig. 5 B); (3) gonopod endomere with a bifurcated shape at the end (Fig. 5 B); (4) gonopod exomere long and pointed, sword-shaped, as long as gonopod endomere (Fig. 5 B). Diagnostic remarks. Based both on the geographic distribution and morphological characters, the new species seems to be especially close to E. tujiaphilus (Liu and Golovatch 2018), from Longshan County, Hunan Province, in which the endomere tip is bifid and the exomere spiniform. However, the two species compared are clearly different: (1) body smaller and transparent white (Fig. 2), vs. body larger and yellowish in E. tujiaphilus; (2) the gonopod endomere is as long as the gonopod exomere (Fig. 5 A), vs. the gonopod endomere is considerably longer than the gonopod exomere. Description. Based on type specimens. Length of body ca 11–13 mm (males) or 12–15 mm (females). Width of body ca 1.5–1.6 mm (males) or 1.7–1.8 mm (females). Coloration: Live specimens semi-transparent to whitish (Fig. 2); in alcohol, light yellowish (Fig. 3). Body: Adults with 20 segments. In width, head <collum <segment 2 <3 <4 <5 <6 <7–16, thereafter body gradually tapering posteriorly towards telson. Head: vertex pubescent, epicranial suture conspicuous (Fig. 4 A), frons with dense short pubescence (Fig. 4 A). Labrum relatively flat and long, with a row of three sharp teeth (Fig. 4 A). Antennae long and slender, slightly clavate, densely setose, in situ extending past ring 4 when extended posteriorly (Fig. 3 B); in length, antennomere 7 <1 <4 = 5 <2 = 6 <3 (Fig. 4 B); antennomeres 5 and 6 each with a distodorsal group of sensilla basiconica (Fig. 4 B); antennomere 6 thick and swollen; antennomere 7 with four sensory cones apically (Fig. 4 C). Exoskeleton: Collum semi-oval, sparsely setose, with a lateral incision on each side (Figs 3 A, 4 B). Paraterga well-developed and mostly slightly upturned dorsally (Fig. 4 D), midbody metaterga ca 1.6 times as wide as prozona (Fig. 3 A). Anterior margins of metaterga forming shoulders (Fig. 3 A). Caudolateral corners of paraterga starting with ring 2 clearly projecting posteriorly past tergal margin and strongly acuminate (Fig. 3 A). Integument shining, translucent, prozona very delicately alveolate (Fig. 3 A). Constriction between pro- and metazona narrow and smooth (Fig. 3 B). Metatergal sculpture faint, with three irregular transverse rows of setigerous polygonal bosses (Fig. 4 D). Sulcus between front and middle rows of setae distinct; that between middle and caudal rows obscure (Fig. 4 D). Tergal setae visible, short. Poreless and pore-bearing paraterga with 3 or 4 faint incisions at lateral margin, respectively. Ozopores located between last and penultimate marginal incisions (Fig. 4 D). Pore formula normal: 5, 7, 9, 10, 12, 13, 15–19. Epiproct process short, conical, slightly surpassing paraprocts caudally, pre-apical lateral papillae small, with two long setae (Fig. 4 F). Hypoproct trapezoid, with two setigerous, conical papillae at caudal margin (Fig. 4 F). Sterna sparely setose, cross-impressions shallow (Fig. 3 B). Rings 5–19 each with two pairs of long legs, tarsi longest, claws curved ventrad and pointed, legs ca 1.5 times as long as body height in both sexes. Neither sphaerotrichomes nor sternal cones, prefemora not bulged laterally (Fig. 4 E). Gonopods: coxite short and stout; prefemorite densely setose, as usual, about 1 / 3 as long as telopodite; femorite with a finger-shaped process (p); clivus (cl) short; endomere (en) with a bifurcated shape at the end; exomere (ex) long and pointed, sword-shaped, as long as endomere; seminal groove (sg) running mostly mesally, then ultimately entering an accessory seminal chamber (Fig. 5).