Eutrichodesmus, Silvestri, 1910

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 : 41-44

Key to the species of Eutrichodesmus

1 At least some metaterga with an evident mid-dorsal outgrowth or projection ( Figs 9 A-D; 20A-D).................................................................................... 2

– All metaterga subequal, devoid of an evident mid-dorsal outgrowth or projection ( Figs 2 A-F, 5A-D; 17A-D)................................................................... 9

2 Only last 3-8 metaterga in front of telson with a very evident mid-dorsal outgrowth. Body with 20 segments............................................................. 3

– Most of metaterga, including some of anterior body portion, with a high, often tuberculated projection ( Figs 9 A-D; 20A-D). Body with 19 or 20 segments.......................................................................................................... 5

3 Metaterga 12-19 each with an increasingly evident, subtriangular, mid-dorsal outgrowth. Cave in Yunnan Prov., China.......................... E. dorsiangulatus

– Only metaterga 16(17)-19 each with an evident, rather rounded, mid-dorsal outgrowth................................................................................................... 4

4 Paraterga narrower. Gonopod process dp less than one-quarter length of acropodite. North Vietnam.................................................. E. armatocaudatus

– Paraterga broader. Gonopod process dp much longer, more than half length of acropodite. Cave in Yunnan Prov., China.......................... E. monodentus

5 Mid-dorsal projections relatively low, not club-shaped, increasingly evident on metaterga 3–17(18) ( Fig. 20A ) .............................................................. 6

– Mid-dorsal projections especially prominent, club-shaped, present on metaterga (4)5-19, only slightly lower on metatergum 19........................... 7

6 Body with 19 segments. Subtriangular mid-dorsal projections evident on metaterga 3-17, only slightly smaller on metatergum 18 ( Fig. 20A ). Gonopod process dp rudimentary ( Figs 22E, F ). Vietnam....... E. asteroides sp. n.

– Body with 20 segments. Clearly tridentate mid-dorsal projections evident on metaterga 3-18, abruptly smaller on metatergum 19. Gonopod process dp small but evident. Malaysia.................................................... E. cavernicola

7 Metatergum 4 with a high mid-dorsal projection ( Fig. 9A ). Paraterga strongly declivous and quadrilobate ( Figs 9 A-D, 10E). Gonopods as in Fig. 11 . Vietnam........................................................................................ E. aster sp. n.

– Mid-dorsal projections absent from metatergum 4. Paraterga less strongly declivous. Gonopods different. Malaysia......................................................... 8

8 Mid-dorsal projections on metaterga 5 and 6 straight in lateral view............. ................................................................................................. E. macclurei

– Mid-dorsal projections on metaterga 5 and 6 slightly inclined anteriorly in lateral view................................................................................ E. reclinatus

9 Body with 19 segments. Collum and metaterga virtually smooth, non-tuberculate, beset with long or short trichome ( Fig. 32 A-F, 33C-E). Paraterga too short to allow complete body volvation ( Fig. 32A ). Gonopod telopodite with a complex, lobiform dp ( Fig. 33F, G ). Southwestern Pacific...................... 10

– Body with 20 segments. Collum and metaterga clearly tuberculate, trichome (if present) usually short ( Figs 25F , 29F ). Paraterga much broader, mostly reaching level of venter, so volvation usually complete. East and Southeast Asia........................................................................................................... 11

10 Collum and metaterga beset with long, 2-segmented, tactile setae. Tip of gonopod telopodite without teeth. Vanuatu.......................... E. communicans

– Collum and metaterga beset with very short trichome ( Figs 32 B-E, 33C-E). Tip of gonopod telopodite with a few teeth ( Figs 33F, G ). Sulawesi, Indonesia..................................................................................... E. reductus sp. n.

11 Paraterga mostly especially wide and only slightly declivous. Caves in Guangxi Province, China........................................................................................ 12

– Paraterga not so wide, strongly declivous ( Figs 2A , 5A , 13A, 17A, 28A) ... 13

12 Collum with a row of conspicuous teeth along fore edge of collum............... ...................................................................................................... E. similis

– Collum with only minute teeth at fore edge of collum...................... E. latus

13 Most metaterga with two transverse rows of bosses. Epiproct very strongly flattened dorsoventrally, subquadrate, spatuliform, with unincised margins. Gonopod telopodite particularly slender, about twice as long as coxa. Shikoku, Japan.......................................................................... E. peculiaris

– Most metaterga with three transverse rows of bosses or conical tubercles. Epiproct never so strongly flattened. Gonopod telopodite usually shorter. Southeast Asia.................................................................................................... 14

14 Paraterga mostly set off laterally at base by a clear sulcus. Metaterga with three mixostictic rows of evident, conical tubercles, each surmounted by a long, 2-segmented seta. Gonopod telopodite with a particularly small, dentiform dp. Thailand.............................................................................. E. gremialis

– Paraterga less markedly (if at all) set off laterally at base ( Figs 2A , 5A , 13A, 17A, 28A), largely continuing general outline of metaterga or nearly so (Figs 18D, 29C). Metatergal trichome very short or missing. Gonopod telopodite different.................................................................................................... 15

15 Paraterga relatively short, volvation apparently imperfect ( Fig. 24A ). Body small, up to 6.5 mm long. Vietnam.......................................................... 16

– Paraterga broad enough to allow complete volvation (Figs 17A, 28A). Body usually larger............................................................................................. 17

16 Entire body pallid, up to 5.0 mm long. Gonopods simple ............. E. basalis

– Vertex, collum, metaterga and much of telson grey, this strongly contrasting with pallid venter and legs ( Fig. 23 ). Body 6.0- 6.5 mm long. Gonopods more elaborate ( Figs 26 C-E)......................................................... E. griseus sp. n.

17 Pattern of metatergal tuberculation isostictic ( Figs 5 A-D). Seminal groove terminating on a very evident, pilose-spiculate pulvillus near base of a relatively shortened, lamellar acropodite ( Figs 6F, G , 7 A-F).... E. regularis sp. n.

– Metatergal tuberculation mixostictic (Figs 13A-F, 24A). Seminal groove terminating distally to subapically, mostly without a pulvillus (seldom with a hairpad) (Figs 18G, H, 30) ....................................................................... 18

18 Distofemoral process of gonotelopodite bare, subunciform, pointed......... 19

– Distofemoral process of gonotelopodite nearly always conspicuously papillate (Figs 18G, H, 30), seldom redumentary (Figs 15A-F), never pointed ....... 20

19 Body ca 8.0 mm long. Gonopod tip bifid. Vietnam.................. E. demangei

– Body ca 14.0 mm long. Gonopod tip simple, unciform. Cave in Yunnan Prov., China............................................................................ E. arcicollaris

20 Paraterga mostly bilobate laterally and unilobate caudolaterally (Fig. 17A). Very small: 4.7-5.3 mm long and 0.65-0.7 mm wide. Gonopods as in Figs 18G, H. Vietnam......................................................... E. curticornis sp. n.

– Paraterga mostly 3- or 4-lobate laterally (Figs 13A-D). Length ≥ 6.0 mm, width ≥ 1.1 mm. Gonopods different ....................................................... 21

21 Metaterga 18 and 19 not elevated dorsally. Caudolateral lobulations mostly deeply incised. Distofemoral process of gonopod bipartite. Caves in Guizhou Prov., China................................................................................... E. incisus

– Metaterga 18 and 19 slightly elevated dorsally ( Figs 28 A-F). Caudolateral lobulations not incised, tuberculiform. Distofemoral process of gonopod unipartite ( Fig. 30 )......................................................................................... 22

22 Body 6.0- 6.5 mm long and 1.1-1.2 mm wide. Ozopores opening on top of porosteles representing penultimate of five lateral lobulations of respective paraterga, with caudolateral lobulations missing. Gonocoxae with only few macrosetae. Gonopods as in Fig. 30 . Laos.................. E. multilobatus sp. n.

– Body ≥ 8.0 mm long and 1.35 mm wide. Ozopores opening dorsally on caudalmost of 3-4 lateral lobulations of respective paraterga, caudolateral lobulations present. Gonocoxae with abundant macrosetae. Gonopods different.... ................................................................................................................. 23

23 Body 8.0- 8.5 mm long and 1.35-1.4 mm wide. Paraterga mostly 3-lobate ( Figs 2 A-G). Gonopods as in Figs 3 E-H. Cave in Guizhou Prov., China....... ....................................................................................... E. distinctus sp. n.

– Body 12-13 mm long and 2.5-2.6 mm wide. Paraterga mostly 4-lobate (Figs 13A-D). Gonopods as in Figs 15A-F. Caves in Thanh Hoa Prov., Vietnam... ........................................................................................ E. filisetiger sp. n.

Figures

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 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 9. Eutrichodesmus aster sp. n., subadult paratype from Tham Han Cave; A, habitus, lateral view; B, anterior part of body, lateral view; C, midbody segments, lateral view; D, posterior part of body, lateral view; E, metatergal seta, sublateral view; F, anterior part of body, frontodorsal view. – Scale bars: A-D, F, 0.5 mm; E, 0.001 mm.

Figure 11. Eutrichodesmus aster sp. n., ♁ paratype from Tham Han Cave; A, B, left gonopod, mesal and lateral views, respectively. – Scale bar: 0.2 mm.

Figure 20. Eutrichodesmus asteroides sp. n., ♀ paratype from Hang Cha Noi Cave; A, habitus, lateral view; B, E, anterior part of body, lateral and frontal views, respectively; C, F, midbody segments, lateral and dorsal views, respectively; D, posterior part of body, lateral view. – Scale bars: A-F, 0.5 mm.

Figure 22. Eutrichodesmus asteroides sp. n., ♀ (A-D) and ♁ (E-F) paratypes from Hang Cha Noi Cave; A, midbody metaterga, sublateral view; B, C, texture of tegument, dorsal view; D, setae on antennae; E, F, left gonopod, mesal and lateral views, respectively. – Scale bars: A, 0.05 mm; B, 0.1 mm; C, 0.01; D, 0.005 mm; E, F, 0.2 mm.

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.

Figure 28. Eutrichodesmus multilobatus sp. n., ♀ paratype; A, habitus, lateral view; B, D, midbody segments, lateral and dorsal views, respectively; C, G, anterior part of body, dorsal and ventral views, respectively; E, lateral edge of paratergum with ozopore, dorsal view; F, posterior part of body, caudal view. – Scale bars: A, 0.5 mm; B, F, 0.1 mm; C, D, G, 0.2 mm; E, 0.02 mm.

Figure 29. Eutrichodesmus multilobatus sp. n., ♀ paratype; A, midbody segments, ventral view; B, posterior part of body, ventral view; C, cross-section of a midbody segment, caudal view; D, part of head with left antenna, subdorsal view; E, texture of tegument, dorsal view; F, metatergal seta. – Scale bars: A, B, E, 0.1 mm; C, 0.2 mm; D, 0.05 mm; F, 0.02 mm.

Figure 30. Eutrichodesmus multilobatus sp. n., ♁ paratype; A, B, right gonopod, mesal and lateral views, respectively. – Scale bar: 0.3 mm.

Figure 32. Eutrichodesmus reductus sp. n., ♀ paratype; A, habitus, lateral view; B, anterior part of body, lateral view; C, midbody segments, lateral view; D-F, posterior part of body, lateral, dorsal and caudal views, respectively. – Scale bars: A, 0.5 mm; B-F, 0.1 mm.

Figure 33. Eutrichodesmus reductus sp. n., ♀ (A-E) & ♁ (F-G) paratypes; A, head, ventral view; B, midbody segments, ventral view; C, midbody paratergum with ozopore, dorsal view; D, E, texture of tegument, dorsal view; F, G, left gonopod, mesal and lateral views, respectively. – Scale bars: A, B, 0.1 mm; C, 0.02 mm; D, 0.05 mm, E, 0.01 mm; F, G, 0.1 mm.