Eutrichodesmus spinatus, Liu, Weixin & Tian, Mingyi, 2013

Liu, Weixin & Tian, Mingyi, 2013, Four new cavernicolous species of the millipede genus Eutrichodesmus Silvestri, 1910 from southern China (Diplopoda: Polydesmida: Haplodesmidae), Zootaxa 3734 (2), pp. 281-291 : 285-287

Eutrichodesmus spinatus sp. n.

Figs 6–8

Material: Holotype male (SCAU), China, Hunan Prov., Sidu Town, Sidu Caves, 28.06.2011. leg. Tian Mingyi, Gao Qi & Sun Feifei (CHIhn11-LWX01). Paratypes: 1 male, 2 females (SCAU), same locality, together with holotype.

Name: To emphasize the gonopod telopodite carrying a conspicuous, spinigerous, lateral, distofemoral process (dp).

Diagnosis: Differs from congeners by the volvation being apparently imperfect because the paraterga are mostly only slightly declivous; the metaterga behind collum with three transverse isostictic rows of large rounded tubercles; the gonopod telopodite with a conspicuous, spinigerous, lateral, distofemoral process (dp) at about midway while the acropodite is simple and very strongly curved.

Description: All characters as in E. digitatus sp. n., except as follows.

Length of adults of both sexes ca 6.5-8.0 mm, width 1.2-1.5 mm. Holotype ca 7.5 mm long and 1.5 mm wide. Coloration uniformly pallid ( Fig. 6 A).

Conglobation pattern typical of “ Doratodesmidae ”, but volvation apparently imperfect because of paraterga mostly being only slightly declivous, leaving small lacunae laterally even when body is maximally enrolled.

Antennae ( Fig. 3 C) rather short and stout. Collum with five regular transverse rows of large round tubercles ( Fig. 6 B). Limbus not microcrenulate ( Fig. 6 D). Dorsum behind collum with three transverse isostictic rows of large rounded tubercles, each row with about 10 tubercles, but dorsum only with few setae. Paratergal surface coarse, without tubercles; paraterga slightly declivous, broad, 3- or 4-lobate laterally, nearly parallel to level of venter, caudolaterally at base with one distinct impression, thus somewhat interrupting the contour of a convex dorsum ( Figs 6 A-B). Paraterga 2 strongly enlarged, with three lobulations anterolaterally. Paraterga 3 and 4 slightly shorter than others, each with three lobulations anterolaterally. Pleurosternal ridges wanting.

Sterna between ♂ coxae 6, 7 and 9 much wider. Legs rather long and relatively slender, reaching tips of paraterga; femora and tarsi longest, subequal in length; some setae with microdenticulations ( Fig. 6 E).

Gonopods ( Figs 3 F-H) very simple. Coxae subquadrate, large, microtuberculate and abundantly setose ventrolaterally. Telopodite longer than coxite, slender throughout, setose in its basal half, with a conspicuous, spinigerous, lateral, distofemoral process (dp) at about midway. Acropodite very strongly curved ventrad; seminal groove terminating subapically with a hairpad.

Remarks: This is a typical “doratodesmid”, possibly a troglobite.

Figures

FIGURE 3. Eutrichodesmus simplex sp. n., male paratype. A. body, dorsal view. B-C. anterior body part, lateral and ventral views, respectively. D-E. midbody segments, lateral and ventral views, respectively. F-G. posterior body part, dorsal and ventral views, respectively. Photographed not to scale.

FIGURE 6. Eutrichodesmus spinatus sp. n., male holotype. A. body, dorsal view. B-C. anterior body part, ventral and dorsal views, respectively. D-E. midbody segments, ventral and dorsal views, respectively. F-G. posterior body part, ventral and dorsal views, respectively. Photographed not to scale.

FIGURE 7. Eutrichodesmus spinatus sp. n., male holotype. A. midbody segments, lateral view. B. both gonopods in situ, ventral view. C-D. gonopod, lateral and mesal views, respectively. Photographed not to scale.

FIGURE 8. Eutrichodesmus spinatus sp. n., A-B. right gonopod, lateral and mesal views, respectively. Scale bar: 0.1 mm.