Eutrichodesmus curticornis 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 : 21-24

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

urn:lsid:zoobank.org:act:AEBAEF74-7FF7-4E99-8108-D0D85ACE06C3

Figs 16-18

Type material: Vietnam, Nghê An Prov., Anh Son: Hoi Son, Hang Lung Bo Cave , hand collected, 19.I.2003, leg. L. Deharveng and A. Bedos (VIET-901), holotype ♁ (MNHN JC 321), paratypes: 1 ♀ (MNHN JC 321), 1 ♀ (SEM) .

Name: To emphasize the unusually short antennae.

Diagnosis: Differs from congeners by the perfect volvation, coupled with the very short antennae, legs and paraterga, the contiguous paramedian tubercles above the antennal sockets, the regular mixostictic pattern of metatergal tuberculation 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 4.7-5.3 mm, width 0.65–0.7 mm, body broadest at segment 3 or 4. Holotype ca 4.7 mm long and 0.65 mm wide. Coloration uniformly pallid, shown pinkish because of a photographic artifact (Fig. 16).

Adults with 20 segments (Figs 16, 17A), pattern of conglobation typical of “doratodesmids”. Head (Fig. 18A) with a contiguous pair of paramedian tubercles above antennal sockets; antennae very short and clavate, but tegument (Fig. 18E) and many other characters (Figs 18B, C, F) much as in E. distinctus sp. n.; collum rather regularly tuberculate (Fig. 17B). Metaterga behind collum with three transverse, regular, mixostictic rows of rounded, flat, undifferentiated tubercles (Figs 17A, C), each crowned with a broken-off seta (Fig. 18E). Paraterga subvertical, rather wide, slightly surpassing level of venter, with only a slight impression at base and nearly continuing general outline of convex dorsum (Fig. 18D); paraterga 2 (Figs 17A, 18A) evidently lobulate only anterolaterally but not laterally (Fig. 17A). Following paraterga broadly rounded, very slightly bilobate laterally and unilobate caudolaterally (Figs 17A, 18B). Limbus rather irregularly crenulate, almost hidden by nearby abundant microvilli (Fig. 18E). Pore formula normal, ozopores poorly visible, located dorsally near base of ventrocaudal lobulation (Fig. 17A). Epiproct short, with only slightly differentiated tubercles (Fig. 17D).

Legs very short and stout, barely reaching edge of paraterga (Fig. 18F).

Gonopods (Figs 18G, H) relatively complex. Coxae abundantly micropapillate and setose, with a usual, apicolateral lobe. Telopodite elongate, slender, only very slightly arcuate, with a marked, denticulate distofemoral process (dp) at about midway and an evident distolateral tooth; seminal groove terminating without hairpad at base of the tooth.

Remarks: This pallid species shows short antennae, legs and paraterga, all these traits apparently being related to the small body size. It is also a typical “doratodesmid”, possibly yet one more troglobite.

Figures

Figure 16. Eutrichodesmus curticornis sp. n., ♀ paratype; habitus, lateral view. (Photographed not to scale by L. Deharveng).

Figure 17. Eutrichodesmus curticornis sp. n., ♀ paratype; A, habitus, lateral view; B, anterior part of body, dorsal view; C, midbody segment, dorsal view; D, posterior part of body, caudal view. Scale bars: A, 1.0 mm; B-D, 0.1 mm.

Figure 18. Eutrichodesmus curticornis sp. n., ♀ paratype (A-F) and ♁ holotype (G-H); A, anterior part of body, ventral view; B, midbody segments, ventral view; C, posterior part of body, ventral view; D, cross-section of a midbody segment, caudal view; E, texture of tegument; F, legs, caudal view; G, H, right gonopod, lateral and mesal views, respectively. – Scale bars: A-D, G, 0.1 mm; E, 0.01 mm; F, H, 0.02 mm.

Figure 2. Eutrichodesmus distinctus sp. n., ♁ paratype; A, habitus, lateral view; B, E, anterior part of body, lateral and dorsal views, respectively; C, F, midbody segments, lateral and dorsal views, respectively; D, G, posterior part of body, lateral and dorsal views, respectively. – Scale bars: A, 0.5 mm; B-G, 0.2 mm.

Figure 3. Eutrichodesmus distinctus sp. n., ♁ paratypes; A, midbody segments, ventral view; B, telson, ventral view; C, anterior part of body, ventral view; D, texture of tegument, dorsal view; E, both gonopods in situ, ventral view; F-H, gonopod, ventral, mesal and lateral views, respectively. – Scale bars: A, 0.5 mm; B, E, G, 0.1 mm; C, H, 0.2 mm; D, 0.02 mm; F, 0.05 mm.

Figure 4. Eutrichodesmus regularis sp. n., ♁ paratype; habitus, lateral view. (Photographed not to scale by L. Deharveng).

Figure 5. Eutrichodesmus regularis sp. n., ♁ paratype; A, habitus, lateral view; B, E, anterior part of body, frontodorsal and ventral views, respectively; C, midbody segments, dorsal view; D, F, posterior part of body, dorsal and ventral views, respectively. – Scale bars: A, C, 0.5 mm; B, D-F, 0.2 mm.

Figure 6. Eutrichodesmus regularis sp. n., ♁ paratype; A, texture of tegument, dorsal view; B, metatergal tubercle, dorsal view; C, metatergal seta, dorsal view; D, cross-section of a midbody segment, caudal view; E, midbody legs, caudal view; F, segments 7 and 8, ventral view; G, left gonopod in situ, caudoventral view. – Scale bars: A, B, 0.05 mm; C, 0.01 mm; D, F, 0.2 mm; E, G, 0.1 mm.

Figure 7. Eutrichodesmus regularis sp. n., ♁ paratypes; A-F, gonopods, frontoventral, submesal, mesal, mesal, mesal and lateral views, respectively. – Scale bars: A-C, 0.1 mm; D, 0.05 mm; E, F, 0.2 mm.

Figure 19. Eutrichodesmus asteroides sp. n., ♁ paratype from Hang Cha Noi Cave; habitus, lateral view. (Photographed by L. Deharveng).

Figure 8. Eutrichodesmus aster sp. n., ♁ paratype from Tham Han Cave; habitus, lateral view. (Photographed not to scale by L. Deharveng).