Epanerchodus parvus Liu & Golovatch 2018, new species
Creators: name: Liu, Weixin
name: Golovatch, Sergei
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Polydesmida
Polydesmidae
Epanerchodus
Epanerchodus parvus

description: Epanerchodus parvus, new species
Figs 10–11.
Material examined: Holotype male (SCAU eGZ7-1) from China, Guizhou Province, Qiandongnan Autonomous Prefecture, Cenggong County, Pingzhuang Town, Wanfuchangcheng Dong Cave, 29.VI.2014, colls: Mingyi Tian, Weixin Liu, Haomin Yin, Sunbin Huang and Xinhui Wang. Paratypes: 8 males, 20 females (SCAU eGZ7-2), same data as the holotype.
Diagnosis: Adult males of E. parvus n. sp. are distinct from other Epanerchodus species based on the following combination of characters: (1) body small (ca 13–16 mm); (2) collum broader than head (Fig. 10A); (3) gonopodal clivus broadly triangular; (4) endomere at base with a small, digitiform, lateral process (p), while its tip beak-shaped and denticulate near apex (Fig. 11).
The former character is similar to that observed in E. gladiatus n. sp., E. chutou n. sp. (both from caves in Guizhou, China) and E. fuscus (from Yunnan, China). However, E. parvus n. sp. is distinguished not only in gonopodal structural details, but also by the narrower body: widths of pro- and metazonae 0.8–1.0 and 1.3–1.5 mm vs. clearly broader in E. gladiatus n. sp., E. chutou n. sp. and E. fuscus: widths of pro- and metazonae 1.2–1.3 and 2.5–3.0, 1–1.2 and 2.0, and 2.3 and 4.0 mm, respectively.
Description: Based on type specimens. Lengths of body ca 13.5–15.5 mm (males) or 15–17 mm (females), widths of pro- and metazonae 0.8–1.0 and 1.3–1.5 mm (males) or 1.01–1.2 and 1.7–1.8 mm (females). Coloration: in alcohol generally pallid. Mouthparts and gonopodal telopodites light yellowish. Body: Adults with 20 rings. Width: collum <head = rings 2–3 <4 <5–15, thereafter body gradually tapering towards telson. Head: clypeus densely pilose, vertex sparsely setose, epicranial suture conspicuous (Fig. 10B). Antennae long, reaching behind posterior margin of ring 3 when extended posteriorly, slightly clavate (Figs. 10A, B, G). Exoskeleton: Collum fanshaped, with a lateral incision on each side (Fig. 10A). Paraterga narrow (Fig. 10), midbody paraterga extend metatergite to ca 1.5x width of prozonite. Paraterga on collum and rings 2–4 clearly upturned dorsally above a faintly convex dorsum, other paraterga flat. From ring 10 on, caudolateral corners of paraterga increasingly acuteangled, sharper and pointed on rings 15–19 (Fig. 10D). Integument shining, translucent, prozonae very delicately alveolate. Limbus regularly denticulate. Constriction between pro- and metazonae narrow, shallow and smooth. Metatergal sculpture faint, with three irregular transverse rows of setigerous, polygonal bosses. Sulcus between front and middle rows of setae a little deeper than that between middle and caudal rows. Tergal setae invisible. Three or four faint setigerous incisions at lateral margins of poreless and pore-bearing rings, respectively. Pore formula normal: 5, 7, 9, 10, 12, 13, 15–19, ozopores evident, dorsal, clearly set off from lateral margin and located between last and penultimate marginal incisions. Epiproct short, conical, pre-apical lateral papillae small. Hypoproct subtrapeziform, with two setigerous papillae. Pleurosternal carinae small, present only on ring 2. Sterna sparsely setose, cross-shaped impressions shallow. Legs long and slender (Fig. 10), about 2.0–2.2 times as long as body ring height in both sexes, without sphaerotrichomes or sternal cones, prefemora not bulging laterally. Gonopods: slender (Fig. 11). Telopodite mostly suberect. Prefemur densely setose and nearly half the length of telopodite. Clivus (cl) broadly triangular. Endomere (en) tip beak-shaped, denticulate near apex. Endomere at base with a small, digitiform, lateral process (p). Seminal groove starting mesally, then recurving laterad to run into an accessory seminal chamber, the latter opening on a hairy pulvillus. An exomere absent.
Note: Because of the long slender antennae and legs, and a depigmented cuticle, this species is most likely a troglobite.
Etymology: To emphasize the small size of this species; masculine adjective.
description: Published as part of Liu, Weixin & Golovatch, Sergei, 2018, The millipede genus Epanerchodus Attems, 1901 in continental China, with descriptions of seven new cavernicolous species (Diplopoda, Polydesmida, Polydesmidae), pp. 53-84 in Zootaxa 4459 (1) on pages 65-67, DOI: 10.11646/zootaxa.4459.1.2, http://zenodo.org/record/1458336