Eutrichodesmus trontelji 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 : 6-12

Taxon classification Animalia Polydesmida Haplodesmidae

Eutrichodesmus trontelji Golovatch, Geoffroy, Mauries & VandenSpiegel sp. n. Figs 7, 8, 9, 10, 11

Type material.

Holotype ♂ (MNHN JC 370), China, Guizhou Prov., Libo County, Libo, Cave Feng Dong, 07.III.1995, leg. P. Trontelj.

Paratypes: 1 ♂, 1 juv. ♀ (MNHN JC 370), 1 ♂ (SEM), same data, together with holotype.

Non-types: 1 ♂, 2 ♀, 11 subadult ♀ or juv. (MNHN JC 370), 1 ♂ (SEM), China, Guizhou Prov., Libo County, Shuipa, Cave Shui Jiang Dong - Cave Shuipu Da Dong, 28.II.1995, leg. P. Trontelj; 1 ♂ (MNHN JC 370), 1 ♂ (SEM), Guizhou Prov., Libo County, Jia Ban, Cave La Tai Dong, 06.III.1995, leg. P. Trontelj.

Name.

In honour of Peter Trontelj, the collector.

Diagnosis.

Differs from congeners by the particularly broad and moderately declivous paraterga which are set at about 45° to the vertical axis and continue the outline of the sides above paraterga, coupled with mostly 4-5 irregular rows of flat setigerous tubercles/bosses per metatergum, the calyx-shaped tergal setae, and the fairly complex gonopod (see also Key below).

Description.

Length of adults ca 8-9 mm, width 1.2 and 2.2 mm (♂ paratype and one ♀ non-type from Shui Jiang Dong) to 1.5 and 2.5 mm (♂ holotype and other non-types) on midbody pro- and metazonae, respectively. Coloration entirely pallid, except some traces of reddish earth material on paraterga.

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

Body with 20 segments (♂, ♀), conglobation pattern typical of “doratodesmoids”, volvation apparently being incomplete because of particularly broad and only moderately declivous paraterga. Antennae rather long and poorly clavate (Figs 7I, 9H, 11I). Collum not covering the head from above, fore margin clearly lobulate and slightly elevated, with abundant flat tubercles/bosses arranged in regular rows only at anterior and posterior margins. 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 (Figs 7 A–G, 9 A–F, 11 A–G); mid-dorsal regions of metaterga not elevated; caudomarginal lobulations numerous, usually evident across the dorsum (Figs 7 A–D, 9 A–C, 11 A–D); limbus microcrenulate (Figs 7 K, 9N, 11K). Paraterga with evident shoulders anteriorly, very broad, moderately declivous, directed ventrolaterad at about 45° to similarly declined sides above paraterga (Figs 7H, 9K, 11H), tips lying very clearly below level of venter, usually rather vaguely uni- to quadrilobate laterally, gradually increasing in number towards paraterga 19; anterolaterals usually wanting, but evident on segment 2 (Figs 7A-D, 9A-C, 11A-D). Paraterga 2 strongly enlarged, directed ventrad (Figs 7A, B, E, I, 9A, D, H, 11A, B, E, I), lateral margin broadly rounded, with few, but evident lobulations; a full row of caudolaterals located above schism, both schism and hyposchism being small (Figs 7B, 9A, 11B). Tergal setae short, 2-segmented, calyx-shaped, apical part setoid (Figs 7L, M, 9 L–O, 11L). Pore formula normal, ozopores indistinct, located at about halfway of paratergite and well removed from lateral margin. Epiproct strongly flattened dorsoventrally, densely tuberculate (Figs 7A, D, G, J, 9C, F, J, 11A, D, G, J). Hypoproct subtrapeziform (Figs 7J, 9J, 11J).

Sterna usually with a rather deep, narrow depression between coxae (Figs 7I, J, 9I, 11I, J). Legs long and slender, about 1.1-1.2 times as long as body height (Figs 7H, J, 9I, K, 11 H–J), only coxae and basal parts of prefemora finely micropapillate (Fig. 8A).

Gonopods (Figs 7 N–P, 8B, C, 9 Q–S, 10, 11 M–O) complex. Coxae subquadrate, large, micropapillate and densely setose on lateral face, with only a small round lobule caudolaterally. Telopodite considerably longer than coxite, moderately curved ventrad, setose over its basal 1/3 until base of a prominent, subspiniform, microtuberculate, sometimes clearly curved, distofemoral process (dp), the latter situated at about halfway of telopodite, acropodite twisted, with a longitudinal mesal fold (fd) only sometimes extended into an apical tooth (j) (non-types), and with (holo- and paratype) or without (non-types) a small ventral tooth (k) at about midway; tip acuminate and axe-shaped; seminal groove terminating subapically on an indistinct hairpad.

Remarks.

The conspecificity of the non-type samples with Eutrichodesmus trontelji sp. n. is documented in Figs 9-11. It is also corroborated by provenance from the same karst in Libo County, Guizhou Province. Small variations seem to only concern gonopod structure, i.e. the presence in the gonopods of the types of a small tooth k and the absence of a tooth j.

Interestingly, calyx-shaped tergal setae among Eutrichodesmus are also observed only in two cavernicolous species from Guangxi: Eutrichodesmus latus and Eutrichodesmus similis (see Golovatch et al. 2009a).