Anoplodesmus lobus, Nguyen & Vu & Nguyen & Le, 2025

Anoplodesmus lobus sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5

Examined material.

Holotype. Vietnam • male; Tuyen Quang Province, Na Hang Nature Reserve ; 18 May 2011; Luong & An leg.; IEBR-Myr 478 .

Paratypes. Vietnam • 1 male, 8 females; Tuyen Quang Province, Na Hang Nature Reserve, Nam Trang Cave, entrance , 22.33423°N, 105.42817°E; 449 m a. s. l.; 18 May 2011; Luong & An leg.; IEBR-Myr 479 GoogleMaps • 7 males, 5 females; Bac Can province, Ba Be National Park ; 22.25083°N, 105.81499°E, 400–500 m a. s. l., 10-11 July 2013; limestone forest; Anh D. Nguyen leg.; IEBRMyr 532 GoogleMaps .

Etymology.

The species epithet “ lobus ” adjective, is used to emphasize the large lobe on gonopod femorite.

Diagnosis.

The species is characterized by having submoniliform body, poorly developed paraterga, gonopod femorite enlarged distad, with a large membraneous lobe and a distal spiniform process on dorsal side; solenophore complex curved down, with two basal spines and a distal laminate lobe; tip strongly bifid; solenomere relatively long.

Description.

Size: body length 31.34–32.11 mm (males), 31.29–32.78 mm (females). Width of midbody pro- and metazona 2.13–2.18 mm (males), 2.88–3.21 mm (females), and 2.45–2.56 mm (males), 3.2–3.47 mm (females), respectively. Length of holotype 31.34 mm, width of pro- and metazona 2.18 and 2.56 mm, respectively.

Coloration generally dark brown, except for yellowish brown middle parts of metaterga, as well as pleura and sterna. Legs pale yellow, antennae light brown.

Head: 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 to segment 4 if stretched laterally. Antennomere 1 = 7 <6 <3 = 4 = 5 <2 in length.

Collum (Fig. 1 A, B View Figure 1 ): a little wider than head, surface smooth, with two rows of setae: 4 + 4 close to anterior margin and 2 + 2 nearly posterior margin.

Body (Figs 1 B, D View Figure 1 , 2 A, C View Figure 2 ) submoniliform, width of body ring 3 <4 <2 = 5, parallel-sided on body rings 5–16, thereafter gradually tapering towards telson. Metatergal surface smooth, shagreened, shining, with only one row of 2 + 2 setae near anterior margin (broken in preserved specimens). Transverse sulcus poorly developed, superficial on metaterga 5–18. Prozona and pleura also shagreened and shining. Stricture dividing pro- and metazona rather distinct and smooth, neither striolate nor beaded (Figs 1 View Figure 1 , 2 View Figure 2 ).

Paraterga (Figs 1 A, B, D View Figure 1 , 2 A, C, D View Figure 2 ) strongly reduced, almost missing, slightly more easily traceable as lateral keels on pore-bearing body 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 body ring 16, missing on subsequent ones (Figs 1 A View Figure 1 , 2 A, C View Figure 2 ).

Telson (Figs 2 C, D View Figure 2 , 3 A View Figure 3 ): Epiproct long and curved down, with four small spinnerets at tip. Hypoproct subtrapeziform, with two distolateral setiferous knobs (Fig. 3 A View Figure 3 ).

Sternites (Figs 1 C View Figure 1 , 2 B View Figure 2 ) sparsely setose, cross-impression with both transverse and longitudinal sulci moderately developed. Sternal cones obvious, front pairs slightly stouter, caudal pairs somewhat slenderer and longer (Fig. 2 B View Figure 2 ). Sternite 5 with an elevated bifid lamina between coxae 4 and a ventrad-elevated setiferous process between coxae 5 (Figs 1 C View Figure 1 , 3 B View Figure 3 ).

Legs slender and long, about 1.7 times as long as body height. Tarsal brushes present until ring 17, thereafter missing. Prefemora swollen dorsally. Femora without modifications.

Gonopod (Figs 4 View Figure 4 , 5 View Figure 5 ) rather complex. Coxite (co) stout, about half length of telopodite, distoventral part sparsely setose. Prefemoral part (pref) as usual densely setose. Femorite (fe) stout, enlarged distad, with a basal straight spine (bsp), a large membraneous lobe (lo), and a small distal spiniform process (dsp) on dorsal side, separated from postfemoral region laterally by a distinct demarcation sulcus. Solenophore very complex, curved down, with two basal spines (bs 1 and bs 2) and a spiniform process (sp) in middle; tip strongly bifid. 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 belongs to the A. elongissimus group with a relatively to extremely long solenomere. It clearly differs from its five congeners, A. elongissimus , A. perplexus , A. spiniger , A. aspinosus , and A. anichkini , in gonopod conformation, especially the solenophore structure.

Habitats.

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