Parariukiaria cucfuongensis, Nguyen, Anh D., 2016

Nguyen, Anh D., 2016, Discovery of a new millipede species in northern Vietnam, and the proposal of a new genus, Parariukiaria (Diplopoda, Polydesmida, Xystodesmidae), Zootaxa 4121 (3), pp. 331-336 : 333-335

Parariukiaria cucfuongensis sp. nov.

( Figs 1–2 )

Examined material. HOLOTYPE: 1 male ( IEBR-Xys001 ) Vietnam, Ninh Binh province, Cuc Phuong National Park (20°19’00”N – 105°36′30″E), forest, 30 April–1 May 2006, leg. Luong Van Hien. PARATYPE: 1 female ( IEBR-Xys002 ) same data as holotype.

Diagnosis. The species differs from its congeners in having leg prefemora with an apicoventral spine; gonopod prefemoral process present, but extremely small, triangular spine; acropodite long, slender and curved at the distal part.

Etymology. To emphasize the Cuc Phuong National Park, in which the type material was found.

Description. Holotype approximately 43 mm in length, width of pro- and metazona about 4.4 and 6.0 mm, respectively. Female slightly larger, length ca. 45 mm, width of pro- and metazona about 4.7 and 6.5 mm. Coloration: Whole body almost uniformly light yellow due to long preservation in 75% ethanol, but prozona seem to be paler than other parts.

Head slightly smaller than collum ( Figs. 1 A, B). Labrum densely setose, but only 3+3 setae on clypeus; frons strongly divided into two parts due to a distinct, deep epicranial suture; each part with two setae arranged in a transverse row. Antennae ( Fig. 1 B) short and stout, somewhat claviform; antenomeres 2 and 6 subequal, but slightly longer than subequal antenomeres 3=5; antennomere 7 shortest; antennomere 1 globose, about half as long as antennomere 2; each antennomere except 7 and 1 with a macroseta dorsodistally.

Collum ( Fig. 1 C) slightly convex and smooth, but a transverse concave suture at 1/3 of its length, without any traces of setae; lateral and posterior margin with weak ridge; lateral corner triangular, but not pointed.

Body parallel-sided ( Figs. 1 D, E) on body rings 2–16, frombody ring 17 gradually tapering towards telson ( Figs. 1 F, G). Both prozona and metazona smooth, shining. Metazona strongly convex; posterior margin with weak ridge; lateral parts expanded pleurad to form well-developed paraterga at ½ body ring height; calluses or lateral margins of paraterga narrow, but evident; caudal corner protruding into a pointed projection, slightly surpassing beyond posterior contour of metaterga, but not reaching to rear metaterga; pointed projections much more obvious and longer on male than on female. Pore formula normal as in polydesmidan species (Body rings 5, 7, 9–10, 12–13, 15–19), ozopores lying at lateral edge at about 2/3 of paratergal length.

Epiproct short, stout tubercle, with 4 long setae on each lateral side; tip concave, with four spinnerets. Paraprocts ( Fig. 1 H) strongly convex, with 2+2 setae on surface. Hypoproct ( Fig. 1 H) triangular with two separated laterodistal setiferous knobs.

Sterna: cross-impression very weak and vague, sparsely setose and without modifications.

Legs short and stout; length less than midbody height; prefemur with apicoventral spine; all podomeres with long setae, especially on dorsal part of tarsi and tibiae.

Male gonopodal aperture on 7th segment ellipsoid, about twice as wide as long. Gonopod ( Figs. 1 I, 2A–D) with coxa short, cylindrical, approximately ½ as long as telopodite, without coxal apophysis, but with a distoanterior macroseta (ms). Cannula normal, on mesal side. Telopodite long, straight, with two simple processes, one being a very short, triangular prefemoral process (pfp), the other a slender, extremely long, curved acropodite (ac). Demarcation between densely setose prefemur and solenomere absent.

Habitats. The species was found in Cuc Phuong which is the most highly conserved area in Vietnam, with primary forest over limestone bedrock. Thus it is unlikely that the species is introduced from elsewhere.

Figures

FIGURE 1. Parariukiaria cucfuongensis sp. nov., holotype. Head, lateral (A), ventral (B), dorsal view (C). Body rings 7 – 10, dorsal (D), lateral (E). Caudal part, dorsal (F), ventral (G). Hypoproct & paraproct (H). Gonopod, mesal view (I).

FIGURE 2. Parariukiaria cucfuongensis sp. nov., holotype, right gonopod, mesal view (A), anterior view (B), lateral view (D); tip of gonopod, mesal view (C). Scale = 1 mm.