Hylomus saiyans Nguyen & Nguyen & Nguyen & Phung 2019, sp. nov.

Hylomus saiyans sp. nov.

(Figs. 1, 21−25) urn:lsid:zoobank.org:act: 949D8441-0F5F-421E-84B1- 7B3688AA04DD

Material examined: Holotype: 1 male (IEBR- Myr 219H) Ninh Binh Province, Cuc Phuong National Park, limestone forest, 11−13 April 2012, coll. Anh D. Nguyen. Paratypes: 1 male, 5 females (IEBR-Myr 219P) same data as for holotype.

Non-types: 1 male (IEBR-Myr 44) Ninh Binh Province, Cuc Phuong National Park, limestone forest, April 2006, coll. Thu-Anh T. Nguyen; 1 female (IEBR- Myr 63) Ninh Binh Province, Cuc Phuong National Park, limestone forest, 30 April 2006, coll. Luong Van Hien.

Etymology: The name refers to naturally aggressive warriors in the Japanese manga “Dragon Ball” by Toriyama Akira (Japan).

Diagnosis: The species differs from its congeners by the second metatergal row having 1 + 1 setiferous spines, others being setiferous knobs. Femora 6 and 7 with a ventral hump, sometimes femur 5 inflated. Gonopod femorite slightly curverd ventrad, enlarged distad; distal part with mesal shelf. Demarcation between femorite and postfemoral region absent. Tip of gonopod acute.

Description: Length ca. 14.2−15.8 mm (male), 13.8−14.2 mm (female); width of midbody pro- and metazonae 0.8−0.9 mm (male), 1.1−1.2 mm (female) and 1.0− 1.1 mm (male), 1.2−1.3 mm (female), respectively. Holotype length ca. 15.8 mm, width of midbody pro- and metazonae 0.8 mm and 1.0 mm, respectively.

Colouration (Figs. 21−23): body generally light brown in male, but darker in female. Legs and sterna brownish yellow.

Head (Fig. 21 A−C) slightly broader than collum in width; surface with dense tiny setiferous spines. Clypeolabral region densely setose. Epicranial suture clearly distinct. Antennae (Fig. 21 A−C) slender and long, reaching segment 6 if stretched posteriorly; antennomere 2> 3> 4 = 5 = 6> 1> 7 in length; antennomere 7 blackish, with four sensory cones at tip.

Collum slightly broader than segment 2 in width, subtrapeziform; surface with dense microgranulation, and two rows of well-developed setiferous spines: 3 + 3 anterior and 1 + 1 posterior. Paraterga spiniform, slightly longer than posterior metatergal spines, directed dorsad.

Width of body segment 3 <4 <2 = 5–17 in width, thereafter gradually tapering towards telson. Prozonae shining and shagreened. Metazonae (terga and pleura) with dense microgranulations. Metaterga with two rows of 1 + 1 anterior small setiferous knobs and 2 + 2 posterior setiferous knobs/spines including well developed, median setiferous spines (Figs. 21A, 21D, 22A, 22C). Pleurosternal carinae absent. Waist between pro- and metazonae broad, not deep, neither striolate nor beaded at bottom. Transverse sulcus incomplete, starting on metatergum 4. Axial line vague.

Paraterga (Figs. 21, 22A, 22C) well developed, antler-shaped, highly elevated from metatergal surface, directed dorsad on segments 2−18, and directed caudad on segment 19. Paraterga with 2 branches on segment 2, 3 branches on segments 3−8, 11, 14, and 18, four branches on segments 9−10, 12−13, 15−17, and spiniform on segment 19. Ozopore on segments 5, 7, 9−10, 12−13, and 15−19, lying at the base of the second branch, invisible from dorsal view.

Epiproct (Fig. 22 B−D) broadly truncated, dorsally inflated, with two lateral setiferous tubercles; tip with four spinnerets. Hypoproct (Fig. 22D) trapeziform, with two well separated, distolateral, setiferous knobs.

Sterna (Fig. 22B) densely setose, cross impression distinct, without modifications except a setiferous trapeziform process between coxae 4 (Fig. 23A).

Legs slender and long, ca. 2−3 times as long as midbody height. Prefemora not swollen. Femora 6 and 7 with a ventral hump, femur 5 sometimes inflated (Figs. 21B, 23B). Tarsal brushes absent.

Gonopod (Figs. 24−25) simple. Coxite short, ca. 1/3 as long as femorite length; distoventral part sparsely setose. Prefemorite densely setose, separated laterally from femorite by a transverse sulcus. Femorite slightly curved ventrad, enlarged distad; distal part with mesal shelf (ms). No demarcation between femorite and postfemoral region. The postfemoral region short, consisting only of solenophore and solenomere. S o l e n o m e r e f l a g e l l i f o r m, p a r t l y s h e a t h e d b y solenophore. Seminal groove running entirely mesally, directed distodorsad before entering the solenophore. Tip of solenophore acute.