Desmoxytes takensis Srisonchai, Enghoff & Panha

Srisonchai, Ruttapon, Enghoff, Henrik, Likhitrakarn, Natdanai & Panha, Somsak, 2016, Four colorful new species of dragon millipedes, genus Desmoxytes Chamberlin, 1923, from northern Thailand (Diplopoda: Polydesmida: Paradoxosomatidae), Zootaxa 4170 (1), pp. 93-113 : 103-107

Desmoxytes takensis Srisonchai, Enghoff & Panha sp. n.

( Figs. 1 E, 1F, 8–10)

Holotype. male ( CUMZ) THAILAND, Tak Province, Phobphra District, Nangkruen waterfall, on litters and under decaying bark, 16º24'36"N, 98°41' 21"E, ca 398 m a.s.l., 15 January 2015, leg. R. Srisonchai, T. Seesamut and P. Jirapatrasilp.

Paratypes. 12 males, 10 females, 1 juvenile ( CUMZ), 2 males, 1 female ( ZMUC) same data with holotype ; 2 males, 1 female ( CUMZ) same locality, 18 January 2011, leg. C. Sutcharit, R. Chanabun, N. Likhitrakarn and T. Krutchuen.

Etymology. The name is Latin adjective referring to the province where the type locality occurs.

Diagnosis. Paraterga winglike, metaterga 2–8 with 2+2 anterior and 2+2 posterior spines, metaterga 9–19 with 2+2 anterior and 3+3 posterior spines. Sharing these characters with D. taurina , D. purpurosea and D. breviverpa sp. n, but differs by its red live color; by smaller paraterga; by the sternal process between male coxae 4 being subtrapeziform; by lamina lateralis (ll) being subtriangular with a thumblike ventral lobe, and by having one conspicuous process and one lobe on lamina medialis (lm).

Description. Length 24–26 mm (male), 25–27 mm (female), width of midbody prozona and metazona ca 1.5 and 1.9 mm (male), 1.7 and 2.2 mm (female).

Live coloration of body bright red; paraterga, surface below paratega and metaterga red; head, antennae, legs and epiproct brown red ( Figs. 1 E, 1F). Coloration in alcohol after twelve months changed to pale brown; paraterga, surface below paraterga, legs and sterna brown to yellow; head, antenna and epiproct brown.

Width of head = collum = segment 2 = 3 = 4 <5 <6–16, thereafter body gradually tapering towards telson. Head width ca 2.0 mm (male), 2.5 mm (female). Clypeolabral region, labrum and genae sparsely setose; epicranial suture distinct as brownish stripe ( Figs. 10 A, 10D). Antennae very long and slender, surpassing segments 6 (male) and 5 (female), when stretch backward dorsally ( Fig. 10 D).

Collum width 2.5–3.0 mm (both sexes), with three transverse rows of setiferous tubercles; 4+4 anterior, 1+1 intermediate and 2+2 posterior tubercles, intermediate tubercles larger than other ones, lateral tubercles of posterior row displaced anteriad; paraterga wing-shaped, subhorizontal, elevated at 10–15º, ending in sharp point, with a setiferous notch at about halfway ( Fig. 10 A).

Post-collum segments with surface metazona and surface below paraterga microgranulate; prozona shagreened; sterna and paraterga smooth ( Figs. 8 A–H, 10G). Suture between prozonae and metazonae conspicuous, wide ( Figs. 8 C, 10B, 10E, 10G). Metaterga with two transverse rows of setiferous spines; metaterga 2–8 with 2+2 anterior and 2+2 posterior spines; metaterga 9–17 with 2+2 anterior and 3+3 posterior spines; lateral spines of posterior rows longer than mesal ones; metaterga 18 and 19 with 2+2 anterior spines and 3+3 posterior tubercles, subequal in size. Transverse sulcus on metaterga visible on segments 6–17, incomplete on segments 5 and 18, absent on segments 2, 3, 4 and 19. Mid-dorsal line missing ( Figs. 8 A, 8C, 8F, 10A–C).

Paraterga strongly developed, especially well in male, winglike, directed dorsolaterad at about ca 45º ( Fig. 10 F); shoulder present, quite narrow; calluses present; anterior margin with two conspicuous denticles; on segments 9, 10, 12, 13, 15–18 with a very small additional denticle close to the tip ( Fig. 10 H); tip narrow and sharp; posterior margin almost straight ( Figs. 8 C, 8E, 10H). Ozopore (op) large, ovoid, visible from above ( Figs. 8 C, 8E, 10H). Pleurosternal carinae forming a complete, toothlike crest only on segment 2 (both sexes), a small crest on segment 3, absent on remaining segments ( Fig. 8 B).

Epiproct conical, flattened dorsoventrally; tip subtruncate; apical papillae inconspicuous, without tubercles; two pairs of paramedian setae without tubercles, lateral papillae conspicuous, lying close to the tip ( Figs. 10 J–K). Hypoproct subsemicircular, caudal margin slightly convex, very small inconspicuous tubercles on caudal edges ( Fig. 10 I).

Sterna sparsely setose, cross-impression shallow; sternal process between male coxae 4 modified, subtrapeziform, stout, tip rounded, with two pores in posterior view ( Figs. 8 G, 8H, 10M). Legs very long and slender, ca 3.0 (male), 2.6 times (female) as long as midbody height ( Fig. 10 P). Male femora 5 and 6 distinctly humped in ventral part ( Fig. 8 I, 10N, 10O).

Gonopods ( Figs. 9 , 10 R–T) suberect and long, distal parts strongly condensed. Coxa (cx) about half as long as telopodite, with long sparse setation distoventrally. Prefemorite (pfe) densely setose, almost 1/3 as long as telopodite, a bit shorter than femorite. Femorite (fe) elongate and slender; seminal groove running on mesal surface; apically with conspicuous lateral and mesal sulcus demarcating femorite and postfemoral part ( Fig. 10 S: arrow). Solenophore (sph) well-developed: lamina lateralis (ll) subtriangular, inner surface subsided; with a huge thumblike ventral lobe, directed in vertical plane ( Fig. 10 R, arrow): lamina medialis (lm) with a prominent process, directed almost in vertical plane, tip sharp and a bit curving down ( Fig. 10 T: black arrow); with a lamellar lobe curving in horizontal plane, tip projecting into solenomere ( Fig. 10 T: white arrow). Solenomere long, flagelliform, straight.

Distribution and habitat. Known only from the type locality. Almost all specimens of this species were found on humid litter surrounding the waterfall nearby a concreted natural board trail. Interestingly, we saw some specimens which were crawling on plastic garbages. The waterfall is a popular tourist attraction located just opposite the main road connecting to human habitation.

Remark. The noticeable red body color is clearly aposematic.

Figures

FIGURE 1. Live photographs of the new species. A, B: Desmoxytes des sp. n. — A; male holotype, B; female. C, D: Desmoxytes breviverpa sp. n. — male paratype. E, F: Desmoxytes takensis sp. n. — E; male paratype, F; female. G, H: Desmoxytes pinnasquali sp. n. — G: male holotype, H: mating couple.

FIGURE 8. Desmoxytes takensis sp. n. (male holotype). A, B: anterior body parts—dorsal view (A) and lateral view (B). C: segment 10 (op = ozopore) — dorsal view. D, F, J: posterior body parts—lateral view (D), dorsal view (F) and ventral view (J). E: segments 10 – 12 (op = ozopore) — lateral view. G, H: sternal process between male coxae 4 — ventral view (G) and lateral view (H). I: legs 4 – 6 — anterior view.

FIGURE 9. Desmoxytes takensis sp. n. (male paratype), right gonopod. A: lateral view. B: mesal view. C: ventral view. D, F: subdorsal view. E: dorsal view.

FIGURE 10. Desmoxytes takensis sp. n. (male holotype). A: head and segments 1 – 3 — dorsal view. B: segments 8 – 10 (op = ozopore) — dorsal view. C: posteriormost segments and telson segments—dorsal view D: head and antenna—anterior view. E: segments 9 – 11 — lateral view. F: segment 10 — posterior view. G: paraterga and sculpture of segment 10 — lateral view. H: paraterga of segment 10 (arrow = tiny denticle) — lateral view. I: last segment and telson; showing epiproct and hypoproctventral view. J – L: epiproct; J: dorsal view, K: lateral view, L: ventral view. M: sternal process between male coxae 4 — posterior view. N: male leg 5. O: male leg 6. P: male right anterior leg of segment 10. Q – T: right gonopod; Q: mesal view (cx = coxa, ca = cannula, pfe = prefemorite, fe = femorite, sg = seminal groove, sph = solenophore), R: lateral view (arrow = thumblike ventral lobe), S: ventral view (black arrow = mesal sulcus, white arrow = lateral sulcus), T: dorsal view (sl = solenomere, ll = lamina lateralis, lm = lamina medialis, black arrow = process, white arrow = lamellar lobe).