Anoplodesmus bilobus, Nguyen & Vu & Nguyen & Le, 2025

Anoplodesmus bilobus sp. nov.

Figs 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10

Examined material.

Holotype. Vietnam • male; Bac Giang Province, Son Dong District, Tay Yen Tu Natural Reserve, Khe Ro ; forest; 17–18 May 2013; Phung Thi Hong Luong leg.; IEBR-Myr 510 H .

Paratypes. Vietnam • 3 males, 4 females; same data as for the holotype; IEBR-Myr 510 P • 2 males; Vinh Phuc Province, Phuc Yen town, Me Linh station for biodiversity ; forest; 9–16 September 2016; Anh D. Nguyen leg.; IEBR-Myr 565 .

Etymology.

The species epithet “ bilobus ” adjective, is used to emphasize the solenophore being strongly divided into two large lobes.

Diagnosis.

The species is characterized by having sub-moniliform body, poorly developed paraterga, gonopod femorites stout, somewhat waisted at the middle, basal part swollen dorsally, and separated from postfemoral region laterally by a distinct demarcation sulcus; solenophore rather simple, with only a long basal process, coiled posteriad; solenomere relatively long.

Description.

Size: body length 13.5–15.0 mm (males), 17.66–18.85 mm (females). Width of midbody pro- and metazona 1.04–1.19 mm (males), 1.51–1.68 mm (females), and 1.20–1.27 mm (males), 1.57–1.76 mm (females), respectively. Length of holotype 14.44 mm, width of pro- and metazona 1.10 and 1.24 mm, respectively.

Coloration: generally reddish brown, except for a brownish yellow broad, longitudinal band in middle metaterga, as well as lower part of pleura and sterna. Legs pale yellow, antennae light brown, except antennomeres 6 and 7 whitish.

Head (Fig. 6 C View Figure 6 ): labrum and frons densely setose, vertex sparsely setose along epicranial suture. Latter deep, distinct, running from rear margin of vertex down to labrum. Antennae slender and very long, reaching behind segment 5 if stretched laterally; antennomere 1 = 7 <6 <5 <2 = 4 in length.

Collum (Fig. 6 B View Figure 6 ): a little smaller than head, surface smooth, with two rows of setae: 4 + 4 close to anterior margin and 2 + 2 nearly posterior margin. All setae broken.

Body (Figs 6 A, B View Figure 6 , 6 D View Figure 6 , 7 A – C View Figure 7 ) submoniliform, width of ring 3 <4 <2 = 5, parallel-sided on rings 5–16, thereafter gradually tapering towards telson. Metatergal surface smooth, shagreened, shining, with only one row of 2 + 2 setae near anterior margin. Transverse sulcus very poorly developed, superficial. Prozona and pleura also shagreened and shining. Stricture dividing pro- and metazona rather distinct and smooth, neither striolate nor beaded.

Paraterga (Figs 6 A, B View Figure 6 , 6 D View Figure 6 , 7 A – C View Figure 7 ) strongly reduced, almost missing, slightly more easily traceable as lateral keels on pore-bearing rings than on poreless ones. Ozopore formula normal, pores located on paraterga 5, 7, 9, 10, 12, 13, and 15–19. Pleurosternal carinae well-developed until segment 16, missing on subsequent ones (Figs 6 A View Figure 6 , 7 A View Figure 7 ).

Telson (Figs 7 D View Figure 7 , 8 A View Figure 8 ): Epiproct long and curved down, with four small spinnerets at tip. Paraprocts semi-circular, each with two setae located on disk. Hypoproct roundly triangular, with two distolateral setiferous knobs (Figs 7 D View Figure 7 , 8 A View Figure 8 ).

Sternites (Figs 7 B View Figure 7 , 8 B View Figure 8 ) sparsely setose, cross-impression with both transverse and longitudinal sulci moderately developed. Sternal cones small but obvious, front pairs even smaller than caudal pairs (Fig. 7 B View Figure 7 ). Sternite 5 with two independent small setiferous rectangular laminae between coxae 4 and two similar laminae between coxae 5 (Fig. 8 B View Figure 8 ).

Legs slender and about 1.6 times as long as body height. Tarsal brushes present until ring 16, thereafter missing. Prefemora swollen dorsally. Femora without modifications.

Gonopod (Figs 9 View Figure 9 , 10 View Figure 10 ) rather complex. Coxite (co) cylindrical, about half length of telopodite, distoventral part sparsely setose. Prefemoral part as usual densely setose. Femorite (fe) stout, somewhat waisted at the middle, basal part swollen dorsally, and separated from postfemoral region laterally by a distinct demarcation sulcus. Solenophore (sph) rather simple, with only a long, posteriad-coiled basal process (lbp). Seminal groove (sg) running distodorsad fully on mesal side of femorite, Solenomere (sl) flagelliform, relatively long, only its proximal half sheathed by solenophore.

Remarks.

The new species obviously belongs to the A. elongissimus group with a relatively to extremely long solenomere. It clearly differs from its congeners in having a simple gonopod solenophore.

Habitats.

The species was found under the leaf litter in moist environments. It moves quickly when disturbed.