Eutrichodesmus griseus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009

Golovatch, Sergei, Geoffroy, Jean-Jacques, Mauriès, Jean-Paul & VandenSpiegel, Didier, 2009, Review of the millipede genus Eutrichodesmus Silvestri, 1910 (Diplopoda, Polydesmida, Haplodesmidae), with descriptions of new species, ZooKeys 12 (12), pp. 1-46 : 29-33

Eutrichodesmus griseus Golovatch, Geoffroy, Mauriès & VandenSpiegel , sp. n.

urn:lsid:zoobank.org:act:E7EB907C-AA5B-4612-B292-403142A55D5B

Figs 23-26

Type material: Vietnam, Kien Giang Prov., Kien Luong: Hon Chong, Nui Hon Chong , outside Cave 2 near Hang Hai Côt , grasses, soil, Berlese extraction, 27.I.2003, leg. L. Deharveng and A. Bedos (VIET-923), holotype ♁ (MNHN JC 323), paratypes: 1 ♁, 1 ♀ (MNHN JC 323), 1 ♀ (SEM) .

Name: To emphasize the greyish coloration of the vertex, collum, metaterga and most of the telson.

Diagnosis: Differs from congeners by the peculiar, grey to blackish coloration, coupled with the relatively short and high paraterga (thus the body apparently not capable of complete volvation) and a few minor details of gonopod structure (in particular, the shape of the telopodite and distofemoral process).

Description: Length of adults of both sexes ca 6.0- 6.5 mm, width 0.7–0.75 mm, body broadest at segment 3 or 4. Holotype ca 4.5 mm long and 2.5 mm wide. Coloration of vertex, collum, following metaterga, and of dorsal and lateral parts of telson greyish to dark grey. Clypeolabral part of head, venter and legs contrastingly pallid ( Fig. 23 ). Holotype light grey.

Adults with 20 segments ( Figs 23 , 24A ), volvation apparently incomplete due to relatively short paraterga. Head ( Fig. 25B ) with a poorly separated pair of paramedian tubercles above antennal sockets; antennae relatively short and clavate; tegument ( Fig. 25F ) and many other characters ( Figs 25 C-E) much as in E. distinctus sp. n.; collum rather regularly tuberculate, anterior row of tubercles especially dense and directed dorsofrontally, thus slightly resembling a pyrgodesmid condition ( Figs 24A, B, F ). Metaterga behind collum with three transverse, regular, nearly isostictic rows of round- ed, flat, undifferentiated tubercles ( Figs 24 A-G), each crowned with a short, 2-segmented, conspicuously denticulate and slightly claviform seta ( Fig. 26B ). Paraterga directed ventrolaterad, short but rather broad, barely reaching level of venter, nearly continuing general outline of convex dorsum ( Figs 24 A-D, 25E); paraterga 2 ( Fig. 24B ) evidently lobulate only laterally. Following paraterga broadly rounded, evidently 3- to 5-lobate laterally, at least bilobate also caudolaterally ( Figs 24 A-D, G). Limbus distinctly spinulate ( Fig. 26A ), almost hidden by nearby abundant microvilli ( Fig. 25F ). Pore formula normal, ozopores located on top of porosteles (always caudalmost lateral lobulation) ( Figs 24 A-D, G). Epiproct rather heavily tuberculate ( Figs 24D, E ).

Legs relatively short and stout, barely reaching edge of paraterga ( Figs 25 C-E).

Gonopods ( Figs 26 C-E) relatively simple. Coxae abundantly micropapillate but only with two macrosetae near base of a small apicolateral lobe. Telopodite elongate, rather slender, evidently arcuate, with a rudimentary, subtriangular, distofemoral process (dp) at about midway and an evident lateral, digitiform solenomere bearing a large hairpad apically and subapically, and a simple dentiform acropodite mesally.

Remarks: Because this pigmented species obviously shows incomplete volvation, it is not a typical “doratodesmid”, definitely epigean. Moreover, because of the elevated anterior row of tubercles on the collum, superficially it slightly resembles certain Pyrgodesmidae .

Figures

Figure 23. Eutrichodesmus griseus sp. n., ♀ paratype; habitus, lateral view. (Photographed not to scale by L. Deharveng).

Figure 24. Eutrichodesmus griseus sp. n., ♀ paratype; A, habitus, lateral view; B, F, anterior part of body, lateral and frontal views, respectively; C, G, midbody segments, lateral and dorsal views, respectively; D, posterior part of body, lateral view; E, epiproct, dorsolateral view. – Scale bars: A, 0.5 mm; B-G, 0.1 mm.

Figure 25. Eutrichodesmus griseus sp. n., ♀ paratype; A, D, posterior part of body, dorsal and ventral views, respectively; B, anterior part of body, ventral view; C, midbody segments, ventral view; E, crosssection of a midbody segment, caudal view; F, texture of tegument, dorsal view. – Scale bars: A-E, 0.1 mm; F, 0.01 mm.

Figure 26. Eutrichodesmus griseus sp. n., paratypes ♀ (A, B) and ♁ (C, D, E); A, limbus, dorsal view; B, metatergal seta, sublateral view; C-E, left gonopod, mesal, lateral and subfrontal views, respectively. – Scale bars: A, 0.01 mm; B, 0.005 mm; C-E, 0.2 mm.