Epanerchodus bishou, Liu & Huo, 2020

Liu, Weixin & Huo, Qingbo, 2020, Two new species and a new record of polydesmoid millipedes from Jiangsu and Zhejiang provinces, eastern China (Diplopoda, Polydesmida), Zootaxa 4722 (1), pp. 41-49 : 46-48

Epanerchodus bishou , new species

Figs 7–8

Type material: Holotype male ( SCAU), China, Zhejiang Province, Tianmu Mountain Nature Reserve , 30°19.931’N, 119°26.27’E, 502 m a.s.l., 2018-X-12, Qing-Bo Huo leg. Paratypes: 1 male ( SCAU), same locality and data as holotype . 1 male, 1 female ( SCAU), same province, Kaihua County, Gutian , 29°14.787′N, 118°7.496′E, 435 m a.s.l., 2018-X-9, Qing-Bo Huo, Peng Gao leg.

Etymology: This species epithet, bishou in Chinese meaning “dagger”, is used as a noun in apposition and emphasizes the gonopodal femorite with a prominent, long, dagger-shaped process.

Diagnosis: Adult males of E. bishou n. sp. are distinct from other Epanerchodus species by the following combination of characters: (1) broad paraterga (widths of pro- and metazonae 1.6–1.8 and 3.5–3.8 mm, respectively) ( Figs 7B, E, H ); (2) male tibiae and tarsi with sphaerotrichomes ( Fig. 8A ); (3) gonopodal femorite with a prominent, long, dagger-shaped process distally and a curved finger-shaped process medially; (4) endomere tip unequally bifid ( Fig. 8 ).

The new species seems to be particularly similar to E. sphaerisetosus (from Jinhua in Zhejiang, China), but is distinguished by (1) caudolateral corners of paraterga being square ( Fig. 6E ) vs. acute-angled in E. sphaerisetosus ; (2) exomere absent ( Fig. 8 ) vs. exomere present in E. sphaerisetosus .

Description: Based on type specimens. Lengths of both sexes ca. 16–19 mm, widths of pro- and metazonae 1.6–1.8 and 3.5–3.8 mm, respectively.

Coloration: generally yellow brownish to dark brownish ( Fig. 7 ).

Body: Adults with 20 rings. Width: head <collum <ring 2 <3 <4 <5–15, thereafter (rings 16–19) body gradually tapering towards telson.

Head: densely setose, epicranial suture conspicuous ( Fig. 7A ). Antennae long, reaching past middle of ring 3 when extended posteriorly, slightly clavate ( Figs 7 A–C).

Exoskeleton: Collum transversely semi-lunar, with three transverse rows of 4+4 setae and a faint lateral incision/denticle on each side. Paraterga broad ( Figs 7 A–H), midbody paraterga ca. 2.0–2.2x prozonite width. Paraterga 2–3 slightly upturned dorsally above a faintly convex dorsum, following paraterga flat and subhorizontal ( Figs. 7A, D, G ). Caudolateral corners of paraterga nearly square, slightly projecting posteriorly past tergal margin, clearly acute only on rings 17–19 ( Figs 7 G–H). Integument shining ( Fig. 7 ), prozonae delicately alveolate. Limbus regularly denticulate ( Figs 7A, D ). Constriction between pro- and metazonae narrow, shallow and smooth ( Figs 7B, E, H ). Metatergal sculpture faint, with three irregular transverse rows of 3+3 setigerous polygonal bosses. Sulcus between front and middle rows of setae a little deeper than that between middle and caudal rows ( Figs 7B, E, H ). Tergal setae very short, present on rings 18–19. Three or four faint setigerous incisions at lateral margins of poreless and porebearing 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 ( Figs 7B, E, H ). Epiproct short, conical, pre-apical lateral papillae evident. Hypoproct subtrapeziform, with two setigerous papillae ( Figs 7 F–H). Pleurosternal carinae present only on ring 2 in both sexes. Sterna sparsely setose, cross-shaped impressions (both axial and transverse) shallow, clearly broadened between male coxae 7 and 9 ( Fig. 7C ).

Legs: long, but stout, about 1.5 (male) or 1.2 (female) times as long as body height, prefemora not bulging laterally; sphaerotrichomes easily visible ventrally on tibiae and tarsi ( Fig. 7A ).

Gonopods: ( Figs 7C, I , 8 A–B) Coxa large and squarish, densely setose laterally and with a long seta mesally. Prefemur densely setose and nearly half the length of telopodite. Clivus, or distolateral ridge on femorite, short; femorite with a prominent, long, dagger-shaped process (p1) distally and a curved finger-shaped process (p2) medially, the latter carrying a very small tooth (t) at midway. Endomere (en) curved, unequally bifid, tip of longer branch slightly folded. Seminal groove (sg) starting mesally, distally recurved laterad near base of p2, then turning laterobasad to run into an accessory seminal chamber, the latter opening on a hairy pulvillus. An exomere absent.

Remark: Tianmu Mountains is known to be the type locality of four other Diplopoda (Golovatch and Liu, unpublished data).

Figures

FIGURE 6. Epanerchodus campus n. sp., male paratype. A, B: left gonopod, mesal and lateral views, respectively. Abbreviations: en = endomere; l = lobe; p = process; sg = seminal groove; t = tooth.

FIGURE 7. Epanerchodus bishou n. sp., male paratype from Tianmu Mountain Nature Reserve, Zhejiang. A–C: anterior part of body, lateral, dorsal and ventral views, respectively D, E: midbody segments, lateral and dorsal, respectively F–G: posterior part of body, ventral, lateral and dorsal views, respectively I: right gonopod, mesal view.

FIGURE 8. Epanerchodus bishou n. sp., male paratype from Tianmu Mountain Nature Reserve, Zhejiang. A: midbody leg 9, lateral view. B, C: right gonopod, lateral and mesal views, respectively. Abbreviations: en = endomere; p1 and 2 = processes 1 and 2; sg = seminal groove; t = tooth. Scale bar: A, 0.4 mm.