Psechrus norops Bayer, 2012

Bayer, Steffen, 2014, Seven new species of Psechrus and additional taxonomic contributions to the knowledge of the spider family Psechridae (Araneae), Zootaxa 3826 (1), pp. 1-54 : 11-13

Psechrus norops Bayer, 2012

Figs 3–4 , 28 A, 31A

Psechrus norops Bayer 2012: 44 , figs 19a–c, 87j, 90j (Description & illustration of ♀).

Material examined (1 ♀, 1 s.a. ♀): MALAYSIA: Peninsula Malaysia: Pahang : Fraser’s Hill , Telecom loop, close to 03°43'06.3''N, 101°45'09.86''E, 1300 m, primary forest, along road, P. Jäger leg. at night, 16.VI.2013, ♀ ( SB 1270 ), s.a. ♀ ( SB 1269 ), SMF 64092 .

Remarks. In a previous study only one female (holotype, SB 860) was examined and subadult females of P. norops were neither described nor illustrated. In the present study an additional female is described and illustrated in order to give information about intraspecific variation. A subadult female collected at the same spot allows for the first time to characterise this species by its primordial female copulatory organ.

Description. Male: unknown.

Female: (measurements of female SB 1270 are listed first, those of the holotype, if different, were taken from Bayer (2012) and are here given in parentheses):

Body and eye measurements: Carapace length 5.4 (5.5), maximal carapace width 3.8, anterior width of carapace 2.4, opisthosoma length 8.6 (7.8), opisthosoma width 4.0 (3.1). Eyes: AME 0.31 (0.34), ALE 0.40 (0.37), PME 0.40 (0.39), PLE 0.40 (0.37), AME–AME 0.17 (0.19), AME–ALE 0.07 (0.08), PME–PME 0.25 (0.27), PME–PLE 0.32 (0.35), AME–PME 0.51 (0.52), ALE–PLE 0.38 (0.43), clypeus height at AME 0.88 (0.69), clypeus height at ALE 0.67 (0.58).

Cheliceral furrow with three promarginal and four retromarginal teeth. Palpal claw with 14 teeth.

Spination: Palp: 131, 110, 1101, 1014. Legs: femur I 446 (656), II 536 (655), III 545 (555), IV 545 (555); patella I–IV 000; tibia I 3038, II 3036, III 3134 (3136), IV 3034 (3136); metatarsus I–III 3035, IV 3023 (3035).

Measurements of palp and legs: Palp 6.7 (6.6) [2.2, 0.9, 1.3 (1.2), 2.3], I 39.9 (37.3) [10.8 (10.0), 2.4 (2.3), 11.3 (10.4), 9.9 (9.3), 5.5 (5.3)], II 30.7 (28.0) [8.6 (8.0), 2.1 (2.0), 8.3 (7.4), 7.4 (6.8), 4.3 (3.8)], III 21.2 (20.3) [6.3 (5.9), 1.5 (1.4), 5.2 (5.0), 5.3 (4.8), 2.9 (2.7)], IV 32.3 (30.3) [9.2 (8.6), 1.8, 8.4 (7.8), 8.2 (7.6), 4.7 (4.5)]. Leg formula: 1423. FEM-I+MTT-I/CL=3.83 (3.51), thus legs long in relation to females of other species-groups. On average, the legs are slightly shorter than in females of other species of the singaporensis -group ( Bayer 2012, p. 37), but it should be emphasised that only two adult females of this species are currently known.

Colouration: As described in Bayer (2012), except for the dark median bands on carapace, which are slightly serrated to serrated (in female holotype at most slightly serrated).

Primordial female copulatory organ: On the basis of its pre-epigyne alone, subadult females of this species are hard to distinguish from P. singaporensis Thorell, 1894 . The posterior part of the pre-median septum of female SB 1269 ( Fig. 4 A, C) is slightly broader than in subadult females of P. singaporensis ( Bayer 2012, fig. 16c). A short pre-epigynal field may be present in P. singaporensis and is missing in the present P. norops specimen. Like in P. singaporensis the lateral margins of the pre-median septum are slightly concave, the pre-epigynal muscle sigilla are slightly elongated and there are four slit sense organs (which is also mostly the case in subadult females of P. singaporensis ). Regarding the pre-vulva, however, the distinction from P. singaporensis becomes clear: it possesses pre-spermathecal heads arising from pre-spermathecae ( Fig. 4 B, D), not from pre-copulatory ducts as in P. singaporensis ( Bayer 2012, fig. 16d). Additionally the pre-spermathecae are distinctly smaller and protrude less far laterally than in P. singaporensis . As in P. singaporensis the pre-copulatory ducts are relatively large and conspicuous ( Fig. 4 B).

Intraspecific variation of female copulatory organs. Specimen SB 1270 differs only slightly from the holotype. The posterior part of the median septum of SB 1270 is very slightly broader than the anterior part ( Fig. 3 A), which is not the case in the holotype, because the epigynal slits are slightly diverging in the latter. The wrinkles at the anterior part of the epigynal field are even less developed than in the holotype ( Bayer 2012, fig.

19a). In SB 1270 the copulatory duct is slightly more distinctly curved medially and the posterior rim of the receptaculum reaches almost as far posteriorly as that of the copulatory duct ( Fig. 3 B), whereas in the holotype the latter reaches further posteriorly ( Bayer 2012, fig. 19b).

Distribution. (Peninsula) Malaysia.

Figures

FIGURE 3. Psechrus norops, copulatory organ of female SB 1270, SMF 64092 from Fraser’s Hill, Pahang Prov., Malaysia. A. Epigyne, ventral view. B. Vulva, dorsal view. CD: Copulatory duct; EF: Epigynal field; EM: Epigynal muscle sigilla; FD: Fertilisation duct; LL: Lateral lobe; MS: Median septum; SB: Spermathecal base; SH: Spermathecal head; SO: Slit-sense organs.

FIGURE 4. Psechrus norops, primordial copulatory organ of s. a. female SB 1269, SMF 64092 from Fraser’s Hill, Pahang Prov., Malaysia. A. Pre-epigyne, ventral view. B. Pre-vulva, dorsal view. C Pre-epigyne, ventral view, photographical image. D Pre-vulva, ventral view, photographical image. PCD: Pre-copulatory duct; PEM: Pre-epigynal muscle sigilla; PMS: Pre-median septum; PSB: Pre-spermathecal base; PSH: Pre-spermathecal head; PSO: Pre-slit-sense organs.

FIGURE 28. Psechrus spp., photographic images of epigynes, ventral view. A. Psechrus norops. B. Psechrus rani. C. Psechrus khammouan. D. Psechrus arietinus sp. nov.. A. SB 1270, SMF 64092, from Fraser’s Hill, Pahang Prov., Malaysia. B. SB 1231, MHNG, from Ba Vi, Ha Noi Prov., Vietnam. C. SB 1255, SMF 63850, from Ban Tathot, Khammouan Prov., Laos. D. Holotype (SB 1189, AMNH) from Tra My, Quang Nam Prov., Vietnam.