Liphistius rostratus Zhan & Xu, 2024

Xu, Xin, Zhan, Yi, Aung, Khin Pyae Pyae, Liu, Fengxiang, Yu, Long & Li, Daiqin, 2024, Four new species of the spider genus Liphistius (Araneae, Mesothelae, Liphistiidae, Liphistiinae) from Myanmar, ZooKeys 1210, pp. 99-115 : 99-115

Liphistius rostratus Zhan & Xu sp. nov.

Figs 9 , 10

Type material.

Holotype: Myanmar ♂, Mandalay Region, War Phyu Taung Vill. ; 22.88 ° N, 96.12 ° E, alt. 553 m; 25. 07. 2019; D. Li et al. leg.; XUX-2019-038 . Paratypes: 2 ♂♂ 3 ♀♀, same data as for holotype; XUX-2019-034 – 037 / 041 .

Diagnosis.

The male of L. rostratus sp. nov. resembles those of L. cupreus , L. nabang , and L. platnicki in having distinctly elevated cumulus (Cu) (Fig. 9 C ), but it can be distinguished from them by the relatively larger paraembolic plate (PeP) (Fig. 9 A, E vs figs 21 A, 23 K in Schwendinger et al. 2022; fig. 3 A in Yu et al. 2021), and an indistinct contrategular process (cp) (Fig. 9 B vs relatively large contrategular process, figs 21 E, 23 E in Schwendinger et al. 2022; fig. 3 B in Yu et al. 2021). The female of L. rostratus sp. nov. resembles to that of L. cupreus in having vesicle clusters along the anterior margin of the poreplate (PPl), but it can be distinguished by the relatively longer posterior stalk ( PS), with a length / width ratio 0.4–0.6 (Fig. 10 vs length / width ratio about 0.2–0.4, fig. 22 in Schwendinger et al. 2022).

Description.

Male holotype. Carapace yellowish brown, with few short, scattered bristles; opisthosoma brown, with 12 brown tergites, close to each other, 2–6 th larger than others, 4 th largest; chelicerae robust, promargin of cheliceral groove with 12 denticles of variable size; labium and sternum yellowish brown, sternum with few short setae on anterior tip and many long setae on elongated posterior tip; legs yellowish brown, with strong setae and spines. Measurements: BL 9.34, CL 4.57, CW 4.26, OL 5.02, OW 3.59; eye sizes and interdistances: AME reduced, ALE 0.40, PME reduced, PLE 0.24, ALE – PLE 0.07, ALE – ALE 0.05, PLE – PLE 0.30; labium 0.98 long and 0.48 wide; sternum 2.09 long and 0.83 wide; legs: I 12.63 (3.80, 1.32, 2.60, 3.07, 1.84), II 13.19 (3.80, 1.32, 2.60, 3.07, 1.84), III 14.35 (3.79, 1.58, 3.33, 3.44, 2.21), IV 19.76 (4.76, 1.66, 4.13, 6.01, 3.20).

Palp: tibial apophysis (TiA) with 4 setae of similar length (Fig. 9 A – C ); paracymbium (PC) with several setae situated on tip (Fig. 9 B, C ); cumulus (Cu) distinct elevated with 5 tapering spines (Fig. 9 C ); subtegulum (ST) without apophysis (Fig. 9 F ); contrategulum (CT) with beak-like projection distally in distal view and small process in ventral view (Fig. 9 B, G ); tegulum ( T) semicircular with flat surface and serrated edges, and proximal tegular margin with an elevated transverse ridge (Fig. 9 B, C, F ); paraembolic plate (PeP) sclerotized, narrow (Fig. 9 A, E ); embolus (E) with 3 distinct longitudinal ridges reaching tip retrolaterally, and several denticles along these longitudinal ridges (Fig. 9 B, F ).

Female paratype ( XUX- 2019-034 ). Carapace brown with few short, scattered bristles; opisthosoma brown, with 12 brown tergites, close to each other, 2–6 th larger than others, 5 th largest; chelicerae robust, reddish brown; promargin of cheliceral groove with 12 denticles of variable size; labium yellowish brown, sternum yellowish brown with several setae; legs with strong setae and spines. Measurements: BL 10.54, CL 4.5, CW 3.93, OL 6.47, OW 4.74; eye sizes and interdistances: AME 0.05, ALE 0.37, PME 0.19, PLE 0.29, AME – AME 0.07, AME – ALE 0.12, PME – PME 0.06, PME – PLE 0.06, ALE – PLE 0.09, ALE – ALE 0.10, PLE – PLE 0.32, AME – PME 0.08; labium 0.95 long and 0.38 wide; sternum 2.41 long and 0.99 wide; palp 7.10 (2.44, 0.98, 1.86, 1.82), leg I 8.89 (2.94, 1.34, 2.00, 1.62, 0.99), II 9.69 (3.40, 1.09, 2.02, 1.98, 1.20), III 9.48 (2.29, 1.05, 2.59, 2.38, 1.17), IV 13.71 (3.21, 1.44, 3.11, 3.80, 2.21).

Vulva: about rectangular poreplate (PPl) with pair of anterior lobes; central dorsal opening ( CDO) located below center of poreplate (PPl); racemose receptacular cluster ( RC) small; posterior stalk ( PS) as wide as poreplate (PPl), lateral margins of genital atrium (GA) slightly sclerotized (Fig. 10 ).

Variation.

Males (N = 3): BL 9.34–10.31, CL 4.57–5.24, CW 4.26–5.83, OL 4.73–5.10, OW 3.40–3.40; females (N = 4): BL 10.54–12.35, CL 4.50–6.31, CW 3.93–5.47, OL 6.47–6.87, OW 4.64–4.79. The number of denticles on the cheliceral promargin varies from 12 to 13 (N = 6). In addition, the male lacking an AME and PME, which may be degenerate during molting, is chosen as the holotype, because all paratype male palps are deformed.

Etymology.

The species name is derived from the Latin word “ rostratus ”, referring to the beak-like contrategulum of the male palp in distal view.

Distribution.

Mandalay Region (War Hpyu Taung), Myanmar.

Figures

Figure 9. Male palp of Liphistius rostratus sp. nov. A, E prolateral view B ventral view C, F retrolateral view D dorsal view G distal view, red arrow shows beak-like contrategular projection. Abbreviations: CT = contrategulum; cp = contrategular process; Cu = cumulus; E = embolus; PC = paracymbium; PeP = paraembolic plate; ST = subtegulum; T = tegulum; TiA = tibial apophysis. Scale bars: 0.5 mm.

Figure 10. Vulva of Liphistius rostratus sp. nov. A, C dorsal view B, D ventral view. Abbreviations: CDO = central dorsal opening; GA = genital atrium; PS = posterior stalk; PPl = poreplate; RC = receptacular cluster. Scale bars: 0.5 mm.