Desmoxytes parvula, Liu, Weixin, Golovatch, Sergei I. & Tian, Mingyi, 2014

Liu, Weixin, Golovatch, Sergei I. & Tian, Mingyi, 2014, A review of the dragon millipede genus Desmoxytes Chamberlin, 1923 in China, with descriptions of four new species (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 448, pp. 9-26 : 11-12

Taxon classification Animalia Polydesmida Paradoxosomatidae

Desmoxytes parvula sp. n. Figs 4, 5, 6

Holotype.

♂ (SCAU), China, Guangxi, Hechi City, Du’an County, Xia’ao Town, cave I, 24°15.144'N, 107°56.272'E, 347 m, 2.V.2013, leg. Tian Mingyi, Liu Weixin, Sun Feifei & Yin Haomin.

Paratype.

1 ♀ (SCAU), same locality and collecting data as of the holotype.

Name.

To emphasize the small size of this species.

Diagnosis.

Differs from congeners in the combination of spiniform paraterga, a paramedian pair of subtrapzoidal processes between ♂ coxae 4, the humped ♂ femur 6, and certain details of gonopod structure.

Description.

Length ca 18 (♂) or 19 mm (♀), width of pro- and metaterga together with paraterga 0.8 and 1.2 (♂), or 1.0 and 1.4 mm (♀), respectively. Head broadest, 1.3 mm (♂) or 1.5 mm (♀) wide. Coloration of material rather uniformly brownish, antennae and lateral body parts dark brown, venter and a few basal podomeres yellowish, basal parts paraterga pink (Fig. 4). Head densely setose, epicranial suture distinct. Antennae long and slender, reaching back to segment 6 (♂) or 4 (♀) when stretched dorsally, antennomeres 5 and 6 each with a compact apicodorsal group of bacilliform sensilla.

Pro- and metazonae very delicately microalveolate, metaterga finely shagreened and transversely rugulose, surface below paraterga finely shagreened (Fig. 4 A–F). Collum with three transverse rows of rather evident spines: 5(6)+5(6) anterior, 4+4 intermediate and 4(5)+4(5) posterior, setae often visible, but sometimes obliterated (Fig. 5A); paraterga spiniform, each with 2 denticles laterally, a spine anteriorly at base (Figs 4A, 5A). Metaterga 2-4 with three transverse rows of setigerous tubercles: 4+4 anterior, 4+4 inermediate, 5+5 posterior. Starting from metatergum 5, anterior row gradually showing 1-2 additional tubercles so that following metaterga with transverse rows of 4-6 irregular tuberculations varying in number, but posterior two rows usually regular, each with (3 –5)+(3– 5) and (5 –8)+(5– 8) tuberculations (Fig. 4B). Metatergum 19 with five rather regular rows of tuberculations. Paraterga spiniform, each with 2-3 denticles (Fig. 4 A–D). ♂ paraterga 2-9 subvertical, following paraterga directed dorsolaterally (Fig. 4 A–B, G), but ♀ paraterga mostly low and short; paraterga 19 directed caudad (Fig. 4C). Ozopores inconspicuous. Transverse sulcus visible on coullum and metaterga 2-18 (Figs 4 B–C, 5A). Pleurosternal carinae poorly developed on segments 2 and 3 both in ♂ and ♀, absent on the rest (Fig. 4D). Epiproct (Fig. 4C) simple, dorsal subapical and, especially, lateral pre-apical papillae very distinct, tuberculiform. Hypoproct (Fig. 4F) subtrapeziform, caudal margin very slightly concave, setigerous cones at caudal edge very small, widely separated. Axial line present.

Sterna moderately setose, cross-impressions very weak (Fig. 4E). A paramedian pair of subtrapzoidal processes between ♂ coxae 4 (Figs 4H, 5B). Legs 1 short, following ones increasingly longer and slenderer towards telson, ca 2.5 (♂) or 2.0 (♀) times longer than body height. ♂ femur 6 with a very evident, digitiform, distoventral apophysis in distal 1/3 (Figs 4I, 5C).

Gonopods (Fig. 6 A–C) simple, strongly elongated. Coxite rather short, subcylindrical, poorly setose distodorsally, about 1/3 as long as telopodite. Prefemoral portion about half as long as acropodite, densely setose. Femorite rather long, strongly curved dorsad, slightly enlarged distally, with seminal groove running entirely on the mesal side. Postfemoral part strongly condensed; solenomere short, flagelliform, sheathed by a similarly short solenophore.

Remarks.

Even though this species has been taken from a cave, it hardly represents a true cavernicole as it is rather strongly pigmented and shows short antennae and legs.