Eviulisoma, Silvestri, 1910

Enghoff, Henrik, 2018, A mountain of millipedes VII: The genus Eviulisoma Silvestri, 1910, in the Udzungwa Mountains, Tanzania, and related species from other Eastern Arc Mountains. With notes on Eoseviulisoma Brolemann, 1920, and Suohelisoma Hoffman, 1963 (Diplopoda, Polydesmida, Paradoxosomatidae), European Journal of Taxonomy 445, pp. 1-90 : 76-79

Key to Udzungwan s. str. species of Eviulisoma

The key is based on adult males. Identifications should always be checked against the species descriptions and illustrations, as additional species of Eviulisoma are expected to exist in the Udzungwa Mts.

1. Sternum 6 with a deep excavation...................................................................................................2 – Sternum 6 not excavated................................................................................................................21

2. Gonopod with an intermediate acropodital process (iap)................................................................3

– Gonopod without an intermediate acropodital process..................................................................15

3. Acropodite with a finger-shaped basal process ( Fig. 9 : bap) ........... E. kwabuniense Kraus, 1958

– Acropodite without a basal process.................................................................................................4

4. Dorsal lobe of solenophore (sph -d) in the shape of a very large hook ( Fig. 13 ) ..... E. cetafi sp. nov.

– Dorsal lobe of solenophore different.................................................................................................5

5. A strong hook emerging from concave side of solenophore ( Fig. 21 : sph-h) ................................. ..................................................................................................................... E. paradisiacum sp. nov.

– No strong hook emerging from concave side of solenophore..........................................................6

6. Large species (width 2.6–3.3 mm) with contrasting dark and pale transverse bands; dorsal lobe of two-lobed solenophore (sph-d) large, as long as acropodital processes and ending in a hook ( Figs 8 A , 12 ) ....................................................................................................... E. akkariae sp. nov.

– Smaller species (width 1.5–2.1 mm), (always?) without contrasting transverse bands; solenophore different..............................................................................................................................................7

7. Gonopods with four very to extremely slender processes ( Fig. 19 : iap, map, sph-d, sph-v) ......... ........................................................................................................................... E. nessiteras sp. nov.

– At least some of these processes stouter .........................................................................................8

8. Intermediate acropodital process (iap) much shorter than mesal acropodital process (map); dorsal lobe of solenophore (sph-d) bifid ( Fig. 17 ) .................................. E. kalimbasiense sp. nov.

– Intermediate acropodital process as long or almost as long as mesal acropodital process; dorsal lobe of solenophore different...........................................................................................................9

9. Mesal acropodital process (map) with a long, curved side branch fitting over semicircular dorsal lobe of solenophore (sph-d) ( Fig. 18 ) ................................................ E. navuncus sp. nov.

– Mesal acropodital process different............................................................................................10

10. Solenophore with three elongate lobes...........................................................................................11 – Solenophore with two lobes, sometimes with a rudimentary intermediate lobe as well............14

11. All three lobes of solenophore of equal length, but intermediate lobe (sph-i) thinner than the others ( Fig. 11 ) ........................................................................................... E. aequilobatum sp. nov.

– The three lobes of solenophore of unequal length........................................................................12

12. Intermediate lobe of solenophore (sph-i) much shorter than the slender, approximately equally long dorsal and ventral lobes (sph-d and sph-v) ( Fig. 15 ) ............................. E. commelina sp. nov.

– Dorsal lobe of solenophore (sph-d) much longer than intermediate and ventral lobes (sph-i and sph-v) ...............................................................................................................................................13

13. Intermediate and ventral lobes of solenophore (sph-i and sph-v) slender; subapical side branch of mesal acropodital process (map) directed laterad ( Fig. 14 ) ....................... E. chitense sp. nov.

– Intermediate and ventral lobes of solenophore (sph-i and sph-v) very short and broad; subapical side branch of mesal acropodital process (map) directed obliquely apicad ( Fig. 20 ) ....................... ........................................................................................................................... E. ottokrausi sp. nov.

14. Solenophore with two broad lobes; mesal acropodital process (map) ending in two subequal points ( Fig. 10 ) .................................................................................................... E. acaciae sp. nov.

– Solenophore with a stout dorsal lobe (sph-d), a slender ventral lobe (sph-v) and a rudimentary intermediate lobe (sph-i); mesal acropodital lobe (map) ending in a hooked point and with a small, pointed subapical side branch ( Fig. 16 ) .......................................................... E. ejti sp. nov.

15. Sternum 6 excavation with four-lobed or angled rim ( Figs 26 A , 30 A , 34F ).................................16 – Sternum 6 excavation with a simple rim (as Fig. 6 A –C )...............................................................18

16. Sternum 6 excavation with angled rim ( Fig. 34F ); mesal acropodital process (map) with large subapical hook opposing corresponding hook on solenophore ( Fig. 34 A –B, D ) ............................ .......................................................................................................................... E. angulatum sp. nov.

– Sternum 6 excavation with four-lobed rim ( Figs 26 A , 30 A ); gonopods different....................17

17. Smaller species (width 2.0 mm); a dentate ridge present on mesal acropodital process (map) ( Fig. 27 ) ............................................................................................................. E. sternale sp. nov.

– Larger species (width 3.0– 3.2 mm); no dentate ridge on map ( Fig. 31 ) .............. E. zebra sp. nov.

18. Gonopod acropodite with a separate basal ʻfemoriteʼ; solenophore large, plate-like ( Fig. 33 ) .... ....................................................................................................................... E. articulatum sp. nov.

– No separate ʻfemoriteʼ; solenophore slender, tube-like (ʻrolled sheetʼ).......................................19

19 Larger species (width 2.5–3.4 mm); ventral margin of mesal acropodital process (map) strongly convex ( Fig. 25 ) ........................................................................................ E. grumslingslak sp. nov.

– Smaller species (width 1.8–2.4 mm); ventral margin of map almost straight..........................20

20. Gonopod coxa with a slender distolateral process ( Fig. 23 A : cxp) ............... E. coxale sp. nov. – Gonopod coxa without a distolateral process ( Fig. 22 ) ..................... E. dabagaense Kraus, 1958

21. Sterna 5 and 6 each with a knob-like process ( Fig. 35 ) ................................ E. biquintum sp. nov. – Sterna 5 and 6 without processes ( Fig. 36 ) ................................................. E. breviscutum sp. nov.

Distribution and habitat patterns

All Udzungwan s. str. species of Eviulisoma are endemic to the Udzungwa Mts. Figure 37 shows the distribution of the 22 species plotted on a diagrammatic map of the areas within the Udzungwas where the species have been collected. Only three species ( E. dabagaense , E. navuncus sp. nov. and

E. nessiteras sp. nov.) have been found in more than one area. The Udzungwa Mts National Park, where the highest number of species (nine) has been found, shares no species with other areas.

Table 4 shows the altitudinal distribution of the Udzungwan s. str. species. Although some species occur as low as 800 m a.s.l., the highest diversity occurs from 1400 m a.s.l. upward. Eviulisoma covers a larger altitudinal spectrum than the Chaleponcus dabagaensis group, which is restricted to 1500–2200 m a.s.l. with a maximum at 1800–2000 m a.s.l. (Enghoff 2014, 2017).

Habitat information is included on the labels of many specimens, and a small amount of habitat information can be extracted from the literature ( Kraus 1958, Frontier Tanzania 2001). In by far the most cases, the habitat is indicated as forest, montane rain forest, tropical semi-evergreen forest, etc. Some species have been collected in open Acacia woodland ( E. acaciae sp. nov., E. grumslingslak sp. nov.) or ʻscrub / thicket/ bushʼ ( E. ottokrausi sp. nov.), but the two last-mentioned have also been collected in proper forests.

Figures

Fig. 6. Eviulisoma spp., male sternum 5 with lobe between 4th legs and sternum 6 with excavation. A–B. E. ejti sp. nov., paratype, sternum 5 and 6. A. Ventral view. B. Sub-posterior view. C. E. acaciae sp. nov., paratype, sternum 6, ventral view. D–F. Sternum 5 lobe, posterior view. D. E. chitense sp. nov., paratype. E. E. dabagaense Kraus, 1958, specimen from Udzungwa Scarp FR, above Chita Village. F. E. coxale sp. nov., specimen from Mito Mitatu. Abbreviation: am = amorphous mass. Scale bars: A–C = 0.2 mm; D = 0.05 mm; E–F = 0.1 mm.

Fig. 8. Gonopods in Eviulisoma spp. A. E. akkariae sp. nov., paratype, right gonopod, colour-coded: light green = coxa; dark green = cannula; light blue = prefemoral part; purplish blue = mesal acropodital process; pink = intermediate acropodital process; orange = solenophore; yellow = solenomere. B. E. culter sp. nov., paratype, right gonopod, solenomere entering solenophore. C. E. ottokrausi sp. nov., paratype, left gonopod, solenomere dislodged from solenophore. Scale bars: A = 0.1 mm; B–C = 0.05 mm.

Fig. 9. Eviulisoma kwabuniense Kraus, 1958, ♂, non-type, from New Dabaga-Ulangambi FR, right gonopod. A. Dorso-lateral view. B. Dorso-mesal view. C. Close-up of basal acropodital process. D. Ventral view. E. Lateral view. Abbreviations: bap = basal acropodital process; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: A–B, D–E = 0.1 mm; C = 0.01 mm.

Fig. 10. Eviulisoma acaciae sp. nov., paratype, left gonopod. A. Mesal view. B. Ventral view. C. Lateral view. D. Acropodite, apical (anterior) view. E. Tip of solenophore, dorso-apical view. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-v = dorsal and ventral lobes of solenophore. Scale bars: A–C = 0.1 mm; D–E = 0.05 mm.

Fig. 11. Eviulisoma aequilobatum sp. nov., holotype, right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Tip of solenophore, sublateral view. E. Dorsal view. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: A–C, E = 0.1 mm; D = 0.05 mm.

Fig. 12. Eviulisoma akkariae sp. nov., paratypes from Udzungwa Mts National Park, Sanje Kati camp and plot (A, C) and Udzungwa Mts National Park, Milo Mitatu (B, D), right gonopods. A. Mesal view. B. Ridged area on inner surface of solenophore. C. Ventral view. D. Lateral view. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemur; ra = ridged area of solenophore; slm = solenomere; sph = solenophore; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore; sr = serrated ridge; tr = transverse ridges. Scales:A, C–D = 0.1 mm; B = 0.05 mm.

Fig. 13. Eviulisoma cetafi sp. nov., paratype, right gonopod. A. Mesal view. B. Meso-dorsal view. C. Latero-ventral view. D. Ventral view. E. Spiny tip of iap. F. Ridged area of solenophore with tip of solenomere sticking out. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; ra = ridged area of solenomere; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: A–D = 0.1 mm; E = 0.01 mm; F = 0.02 mm.

Fig. 14. Eviulisoma chitense sp. nov. paratype. A, C–F. Left gonopod. A. Lateral view. C. Mesal view. D. Ventral view. E. Dorsal view. F. Isolated solenophore, lateral view. B. Lobe between legs 4. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: A–E= 0.1 mm; F = 0.05 mm.

Fig. 15. Eviulisoma commelina sp. nov., holotype, right gonopod. A. Lateral view. B. Mesal view. C. Ventral view. D. Solenophore, dorso-lateral view. E. Dorso-lateral view. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: 0.1 mm.

Fig. 16. Eviulisoma ejti sp. nov., paratype, left gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view. Aluminium tape used for mounting visible in lower left corner of A and D. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: 0.1 mm.

Fig. 17. Eviulisoma kalimbasiense sp. nov., paratype, right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: 0.1 mm.

Fig. 18. Eviulisoma navuncus sp. nov., holotype, right gonopod. A. Mesal view. B. Lateral view. C. Ventro-lateral view. D. Ventral view. Aluminium tape used for mounting visible in lower left corner of B. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; ra = ridged area of solenophore; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: 0.1 mm.

Fig. 19. Eviulisoma nessiteras sp. nov., paratypes from Udzungwa Scarp Catchment FR, right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view. E. Solenophore, latero-ventral view. F. Spiny surface of iap. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; ra = ridged area of solenophore; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: A–E = 0.1 mm; F = 0.005 mm.

Fig. 20. Eviulisoma ottokrausi sp. nov, paratype, left gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Acropodite, latero-ventro-apical view. E. Dorsal view. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore. Scale bars: A–D = 0.1 mm.

Fig. 21. Eviulisoma paradisiacum sp. nov. A–D. Paratype, left gonopod, solenomere dislodged from solenophore. A. Lateral view. B. Ventral view. C. Mesal view. D. Dorsal view. E. Another paratype, gonopod acropodite, apical (anterior) view, solenomere sticking out from solenophore slit. Abbreviations: cxl = coxal lobe; iap = intermediate acropodital process; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-i, sph-v = dorsal, intermediate and ventral lobes of solenophore; sph-h = solenophore hook. Scale bars: A–C = 0.1 mm; D–E = 0.05 mm.

Fig. 22. Eviulisoma dabagaense Kraus, 1958. A–C. Topotype, ♂, left gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D–F. ♂ from Udzungwa Scarp FR, above Chita Village, right gonopod. D. Ventrolateral view. E. Sternal lobe between legs 4. F. Subdorsal view, emphasizing solenophore. Abbreviations: cxl = coxal lobe; map = mesal acropodital process; prf = prefemur; slm = solenomere; sph = solenophore; sph-p = slender process from sph. Scale bars: A–E: 0.1 mm; F = 0.05 mm.

Fig. 23. Eviulisoma coxale sp. nov. A–D. Holotype, right gonopod. A. Mesal view. B. Ventral view. C. Dorsal view. D. Lateral view. E. Paratype from Mito Mitatu, right gonopod, showing lump of amorphous mass on tip of process map. Abbreviations: am = amorphous mass; cxl = coxal lobe; cxp = coxal process; map = mesal acropodital process; prf = prefemur; sph = solenophore. Scale bars: 0.1 mm.

Fig. 25. Eviulisoma grumslingslak sp. nov., paratype, right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Lateral view, detail, showing coxal lobe and entrance of solenomere into solenophore. Abbreviations: cxl = coxal lobe; map = mesal acropodital process; prf = prefemur; slm = solenomere; sph = solenophore.Scale bars: A–B = 0.2 mm; C–D = 0.1 mm.

Fig. 26. Eviulisoma sternale sp. nov., holotype. A. Ventral side of 6 th body ring with right side legs, showing lobed rim of excavation. B. Post-gonopodal leg, showing smooth prefemur and femur. C. Pregonopodal leg, showing scopula. Scale bars: 0.1 mm.

Fig. 27. Eviulisoma sternale sp. nov., holoype, right gonopod. A. Mesal view. B. Ventral view. C. Tip of mesal acropodital process (map), ventral view. D. As C, dorsal view. E. Lateral view. Abbreviations: cxl = coxal lobe; dr = dentate ridge; map = mesal acropodital process; prf = prefemoral part; sph = solenophore; tn1, tn2, tn3 = apical tines of process map. Scale bars: 0.1 mm.

Fig. 30. Eviulisoma Zebra sp. nov., paratype. A. Midbody ring, showing carinulate stricture and ozopore. B. Sternum 6, showing lobate rim of excavation. C–D. Midbody leg. C. Tarsus and part of tibia, showing scopulae. D. Prefemur and femur, showing dense setation. Abbreviations: oZ = ozopore; str = stricture. Scale bars: A–B = 0.2 mm; C–D = 0.1 mm.

Fig. 31. Eviulisoma Zebra sp. nov., paratypes. A. Paratype 1, right gonopod, mesal view. B–C. Paratype 2, gonopods. B. Lateral view. C. Ventral view; notice lumps of secretion between apical tines. D. Paratype 1, right gonopod, (latero-)ventral view. Abbreviations: am = amorphous mass; cxl = coxal lobe; map = mesal acropodital process; sph = solenophore; slm = solenomere; tn1, tn2, tn3 = apical tines of process map. Scale bars: 0.1 mm.

Fig. 33. Eviulisoma articulatum sp. nov., holotype, right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view. E. Acropodite, distal (-anterior) view. Abbreviations: cxl = coxal lobe; fet = ʻfemoriteʼ; map = mesal acropodital process; ra = ridged area on internal surface of sph; sb = side branch of map; slm = solenomere; sph = solenophore. Scale bars: A–D= 0.1 mm; E = 0.05 mm.

Fig. 34. Eviulisoma angulatum sp. nov., paratype. A–E. Left gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Tips of mesal acropodital process and solenophore, mesal view. E. As D, latero-dorsal view, also showing solenomere. F. Excavation of sternum 6. G. Leg from ring 6. Abbreviations: cxl = coxal lobe; hmap = hook-shaped process of map; hsph = hook-shaped process of sph; prf = prefemoral part; slm = solenomere; sph = solenophore. Scale bars: A–C, F = 0.1 mm; D–E, G = 0.05 mm.

Fig. 35. Eviulisoma biquintum sp. nov., holotype. A–D. Right gonopod. A. Mesal view. B. Ventral view. C. Lateral view. D. Acropodite, subapical view. E. Sternum 5. Abbreviations: cxl = coxal lobe; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph = solenophore. Scale bars: A–C, E = 0.1 mm; D = 0.05 mm.

Fig. 36. Eviulisoma breviscutum sp. nov., paratype from forest below Mwanihana Peak. A–D. Right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view. E. Body rings 5 and 6, showing unmodified sterna. Abbreviations cxl = coxal lobe; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph-d, sph-v = dorsal and ventral lobes of solenophore; st5, st6 = sterna 5 and 6. Scale bars: 0.1 mm.

Fig. 37. Distribution of species of Eviulisoma Silvestri, 1910, in the Udzungwa Mts. The positions of the ovals in relation to each other approximately correspond to the relative position of the Udzungwa Mts National Park, Mt Kalimbasi and the three forest reserves, cf. Fig. 2. Species shared between two or three areas are indicated with coloured text and double-headed arrows.