Eutrichodesmus tenuis Golovatch, Geoffroy, Mauries & VandenSpiegel

Golovatch, Sergei I., Geoffroy, Jean-Jacques, Mauries, Jean-Paul & VandenSpiegel, Didier, 2015, Review of the millipede genus Eutrichodesmus Silvestri, 1910, in China, with descriptions of new cavernicolous species (Diplopoda, Polydesmida, Haplodesmidae), ZooKeys 505, pp. 1-34 : 6

Taxon classification Animalia Polydesmida Haplodesmidae

Eutrichodesmus tenuis Golovatch, Geoffroy, Mauries & VandenSpiegel sp. n. Figs 5, 6

Type material.

Holotype ♂ (MNHN JC 369), China, Guizhou Prov., Guanling County, Yong Ning Town, Cave Yun Dong (Cloud Cave), 01.VIII.2005, leg. L. Latella & D. Avesani.

Paratypes: 1 ♀, 2 subadult ♀ (MNHN JC 369), 1 subadult ♀ (SEM), same data, together with holotype.

Name.

To emphasize the relatively slender body due to subvertical paraterga; adjective.

Diagnosis.

Differs from congeners by the large body size, clearly elevated mid-dorsal regions of most metaterga, coupled with narrow, strongly declivous, subvertical paraterga and a simple, falcate gonopod telopodite carrying a long, spiniform, distofemoral process (see also Key below).

Description.

Length of adults ca 14-15 mm, width 1.8 and 2.5 mm (♂ holotype) or 1.6 and 2.1 mm (♀ paratype) on midbody pro- and metazonae, respectively. Coloration entirely pallid, sometimes (♀ paratype) with traces of reddish earth material on metaterga.

All characters as in Eutrichodesmus triangularis sp. n., except as follows.

Body with 20 segments (♂, ♀), conglobation pattern typical of “doratodesmoids”, volvation apparently being complete because of particularly strongly declivous and short paraterga. Antennae short and clavate (Fig. 5H, K). Collum not covering the head from above, fore margin clearly lobulate and slightly elevated, with 4-5 transverse rows of small, but evident tuberculations, only frontal- and caudalmost rows being regular. Metaterga behind collum with three transverse, rather irregular, mixostictic rows of similarly evident, rounded, setigerous tuberculations extending onto paraterga, usually about 10-11+10-11 per row (Fig. 5 A–G); starting with midbody segments, middle rows clearly enlarged and elevated mid-dorsad, increasingly clearly so towards segment 18 as well (Fig. 5 A–D); a few caudomarginal lobulations evident only on paraterga (Fig. 5 A–D); limbus microcrenulate (Fig. 5N). Paraterga with evident shoulders anteriorly, very strongly declivous, subvertical, directed ventrolaterad at about 75-80° to even more strongly declined sides above paraterga (Fig. 5L), broad, tips lying clearly below level of venter, usually rather vaguely tri- or quadrilobate laterally, without anterolaterals (Fig. 5 A–D, M). Paraterga 2 strongly enlarged, directed ventrad (Fig. 5A, B, E, I), lateral margin broadly rounded, with numerous, very small lobulations, caudal margin with a few lobes located near schism, both schism and hyposchism being small (Fig. 5B). Tergal setae very short, 2-segmented, apical part usually phylloid (Fig. 5P, Q). Pore formula normal, ozopores distinct, located dorsally on small porosteles in posterior 1/3 of paratergite and well removed from lateral margin (Fig. 5 A–D, M). Epiproct finger-shaped, densely tuberculate (Fig. 5D, G, J). Hypoproct subtrapeziform (Fig. 5J).

Sterna usually with a rather deep, narrow depression between coxae (Fig. 5I). Legs short and crassate, about half as long as body height (Fig. 5L), all podomeres except tarsi finely micropapillate (Figs 5R, 6A).

Gonopods (Fig. 6B) very simple. Coxae subquadrate, large, micropapillate and rather densely setose on lateral face, with only a small round lobe caudolaterally. Telopodite considerably longer than coxite, suberect, setose over its basal half until base of a prominent, spiniform, simple, distofemoral process (dp), the latter situated at about halfway along telopodite, acropodite strongly falcate, twisted, subacuminate, simple, devoid of outgrowths; seminal groove terminating subapically at base of a hairpad.

Remark.

More information on this cave and its fauna can be found in Latella and Hu (2008) and in Latella and Zorzin (2008).