Desmoxytes des Srisonchai, Enghoff & Panha, 2016

Srisonchai, Ruttapon, Enghoff, Henrik, Likhitrakarn, Natdanai & Panha, Somsak, 2018, A revision of dragon millipedes I: genus Desmoxytes Chamberlin, 1923, with the description of eight new species (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 761, pp. 1-177: 1

publication ID

http://dx.doi.org/10.3897/zookeys.761.24214

publication LSID

lsid:zoobank.org:pub:91658359-00AE-4319-ACBC-E9C544599C5B

persistent identifier

http://treatment.plazi.org/id/F3238A35-BDD1-A525-A2EE-EDC333861399

treatment provided by

ZooKeys by Pensoft

scientific name

Desmoxytes des Srisonchai, Enghoff & Panha, 2016
status

 

Desmoxytes des Srisonchai, Enghoff & Panha, 2016  Fig. 36

Desmoxytes des  Srisonchai, Enghoff & Panha, 2016: 94.

Material examined. Holotype.

Male (CUMZ), THAILAND, Chiang Mai Province, Fang District, Doi Angkhang, near Royal Agricultural Station, 19°54'26"N, 99°02'26"E, ca. 1426 m a.s.l., 12 August 2014, leg. N. Likhitrakarn.

Paratypes.

2 males, 2 females (CUMZ), same data as holotype. 1 male, 2 females (CUMZ), THAILAND, Chiang Mai Province, Chiang Dao District, Wat Tham Krab, 19°33'32"N, 99°03'47"E, ca. 622 m a.s.l., 25 October 2015, leg. C. Sutcharit, R. Srisonchai, T. Seesamut and A. Pholyotha.

Type locality.

THAILAND, Chiang Mai Province, Fang District, Doi Angkhang, near Royal Agricultural Station.

Diagnosis.

Differs from all other Desmoxytes  species by the combination of the following characters: paraterga knife-like; lateral sulcus (ls) of gonopod shallow; lamina lateralis (ll) separated into two ridges by a deep and wide furrow; process (plm) of lamina medialis long and thin, lamellar, tip dentate or crenate; distal lobe (dlm) of lamina medialis quite long, tip directed ventroanteriad; caudal margin of hypoproct concave or truncate.

Redescription

(updated from Srisonchai et al. 2016). SIZE: Length 26-34 mm (male), 30-34 mm (female); width of midbody metazona ca. 2.5 mm (male), 3.0 mm (female). Width of head < collum < body ring 2 = 3 < 4 ≤ 5 < 6-16, thereafter body gradually tapering toward telson.

COLOUR: In life with body dark brown; paraterga bright pink; head, metaterga and surface below paraterga dark brown; antenna (except distal part of antennomere 7 and antennomere 8 whitish), leg, sterna and epiproct brown; a few basal podomeres pinkish brown or brown. Colour in alcohol: after two years changed to dark brown or pale brown.

ANTENNAE: Quite short, reaching to body ring 3 or 4 (male), and 3 (female) when stretched dorsally.

COLLUM: With 3 transverse rows of setiferous tubercles, 3+3 anterior, 1+1 posterior setae (posterior setae inconspicuous); paraterga of collum low, elevated at ca. 20°-30°, directed almost caudolaterad, with two inconspicuous setiferous notches on lateral margin.

TEGUMENT: Quite dull, but slightly shining; prozona finely shagreened; metaterga and surface below paraterga coarsely microgranulate; collum, paraterga, sterna and epiproct smooth.

METATERGA: With 2 transverse rows of setiferous tubercles; metaterga 2-18 with 2+2 anterior and 2+2 posterior tubercles; metatergum 19 with 2+2 anterior and 2+2 posterior setae.

PARATERGA: Directed caudolaterad on body rings 2-16, elevated at ca. 45° (male) 40° (female); directed increasingly caudad on body rings 17, 18 and 19; anterior margin with 2 distinct notches, on lateral margin of body rings 9, 10, 12, 13, 15-18 with tiny denticle near the tip.

TELSON: Epiproct: tip truncate; lateral setiferous tubercles conspicuous, small; apical tubercles inconspicuous. Hypoproct subtrapeziform; caudal margin quite concave or truncate, with inconspicuous setiferous tubercles.

STERNA: Cross-impressions shallow. Sternal lobe between male coxae 4 swollen, subrectangular, flat when seen in lateral view, tip truncate.

LEGS: Long and slender. Male femora 5 and 6 slightly stout, moderately humped ventrally in middle part.

GONOPODS (Fig. 36): Coxa (cx) longer than prefemur. Cannula (ca) slender. Telopodite quite stout. Prefemur (pfe) half to 2/3 as long as femur. Femur (fe) slightly stout. Mesal sulcus (ms) very deep and narrow, lateral sulcus (ls) shallow (= "poorly developed" in Srisonchai et al. 2016). Postfemur (pof) conspicuous, ventrally narrow. Solenophore (sph) well-developed: lamina lateralis (ll) swollen, laterally with a conspicuous, deep and wide furrow (= sulcus) separating ll into two ridges (inner ridge larger than outer one): lamina medialis (lm) well-developed; process (plm) lamellar, slightly short and thin, base long, tip dentate or crenate, indistinctly separated from distal lobe; distal lobe (dlm) quite long, tip directed ventroanteriad; broad lobe (blm) thick, indentation between broad lobe (blm) and distal lobe (dlm) inconspicuous. Solenomere (sl) quite long, distally twisted.

Distribution and habitat.

Known only from the type locality and nearby areas. This species seems to be rare because we made intensive surveys again in 2015 and 2016, no further specimens were found. As mentioned by Srisonchai et al. (2016), D. des  is known only from two localities (Doi Angkhang and Wat Tham Krab), and we consider it to be endemic to Thailand.

Remarks.

This species exhibits some variation in the gonopods: the tip of process (plm) of lamina lateralis is dentate in some specimens, crenate in others. Desmoxytes des  is easy to discriminate from other dragon millipedes by the distinct shape of paraterga and unique gonopod characters.

Coexisting species.

None known.

Corrections to Srisonchai et al. (2016). Srisonchai et al. (2016, pp. 99-103) wrote in the description of this species that paraterga (including paraterga of collum) are directed dorsolaterad at ca. 30°. They are in fact directed caudolaterad and are elevated at ca. 45° as stated in the updated redescription above. Moreover, Srisonchai et al. also described the surface of metaterga as finely shagreened, but we now regard it as being coarsely microgranulate.