Psechrus obtectus 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 : 26-28

Psechrus obtectus Bayer, 2012

Figs 15–16 , 25 F, 26F, 29B, 32D, 34

Psechrus tingpingensis— Wang & Yin 2001: 341 , figs 31–47 (Description & illustration of ♂ and ♀ and SEM photos of somatic characters, misidentified).

Psechrus obtectus Bayer 2012: 105 , figs 57a–d, 58a–g, 86d, 89d, 92d (Description & illustration of ♂ and ♀).

Material examined (4 ♂, 1 ♀): VIETNAM: Bac Giang Prov.: Luc Nam Distr ., ca. 15 km E of Doi Ngo , above Suoi Mo Waterfall , 21°15'46''N, 106°29'24''E, 120 m, secondary forest, P. Schwendinger leg. 25.– 26.V.2012, sample number VN-12/08 , 2 ♂ ( SB 1234 – 1235 ), MHNG. Quang Ninh Prov.: Yen Tu Mountain , pilgrim trail, 21°08'30''– 21°09'08''N, 106°43'17''– 106°43'14''E, 200–500 m, evergreen forest, P. Schwendinger leg. 27.– 29.V.2012, sample number VN-12/09 , 2 ♂ ( SB 1236 – 1237 ), ♀ ( SB 1238 ), MHNG.

Remarks. In previous studies ( Wang & Yin 2001, there sub P. tingpingensis Yin, Wang & Zhang, 1985 ; Bayer 2012) limited material of this species from only one locality in the region of Hanoi was available. In order to provide further information on body size variation and variation of copulatory organs it is here redescribed.

Description. Male: Body and eye measurements (measurements and spination patterns listed in Bayer 2012 are here partly included; for spination, leg formula, cheliceral dentition etc. the most common patterns are listed first, the less common ones in parentheses with the most uncommon rightmost): Carapace length 8.1–10.0, maximal carapace width 4.5–7.2, anterior width of carapace 3.5–4.0, opisthosoma length 9.4–12.4, opisthosoma width 4.1–5.2. Eyes: AME 0.39–0.46, ALE 0.46–0.52, PME 0.48–0.54, PLE 0.48–0.51, AME–AME 0.22–0.24, AME–ALE 0.04–0.08, PME–PME 0.26–0.31, PME–PLE 0.32–0.42, AME–PME 0.62–0.66, ALE–PLE 0.46–0.52, clypeus height at AME 1.03–1.11, clypeus height at ALE 0.93–1.03.

Cheliceral furrow with three promarginal and five (four) retromarginal teeth.

Spination: Palp: 131, 110, 1101 (all spines on patella and tibia less than half as long as those on femur); legs: femur I 546 (556,654), II 546 (556,566), III 555 (545,565), IV 544 (554,545,553,563,665); patella I–IV 000; tibia I–II 3036, III 2022 (2021), IV 3033 (2030,2031,2034,3030,3032,); metatarsus I–III 3035, IV 3036 (3035,3034).

Measurements of palp and legs. Palp 10.5–12.1 [3.5–4.0, 1.8–2.2, 1.4–1.6, 3.7–4.3], I 64.0–80.7 [16.7–21.5, 3.9–4.6, 17.7–23.3, 18.2–23.0, 7.5–8.3], II 48.1–58.7 [13.0–16.7, 3.4–4.2, 13.0–15.8, 13.1–15.9, 5.5–6.1], III 33.3–47.8 [9.6–10.8, 2.6–2.9, 7.9–9.4, 9.2–10.5, 4.0–4.2], IV 49.6–62.3 [13.6–17.4, 3.1–3.6, 12.5–16.3, 14.3–18.1, 6.1–6.9]. Leg formula: 1423. FEM-I+MTT-I/CL=4.31–4.54, legs in relation to other species-groups short and generally within the range for species of the sinensis -group.

Palpal femur ventrally modified with a quite strongly extended, rounded bulge. Macrosetae ventrally on coxa of leg I present, but inconspicuous and only as apical row, none on trochanter of leg I.

Female (measurements and spination patterns listed in Bayer 2012 are here partly included; for spination, leg formula, cheliceral dentition etc. the most common patterns are listed first, the less common ones in parentheses with the most uncommon rightmost): Body and eye measurements: Carapace length 8.7–10.9, maximal carapace width 4.2–7.9, anterior width of carapace 3.7–4.8, opisthosoma length 12.9–15.5, opisthosoma width 6.8–11.6. Eyes: AME 0.41–0.51, ALE 0.50–0.57, PME 0.48–0.58, PLE 0.49–0.57, AME–AME 0.27–0.28, AME–ALE 0.08–0.11, PME–PME 0.39–0.43, PME–PLE 0.43–0.52, AME–PME 0.66–0.86, ALE–PLE 0.61–0.76, clypeus height at AME 1.31–1.51, clypeus height at ALE 1.03–1.27.

Cheliceral furrow with three promarginal and five (four) retromarginal teeth. Palpal claw with 15–16 (14) teeth.

Spination: Palp: 131, 110, 1101, 1014. Legs: femur I 546 (536,535), II 545 (556,536), III 545 (555,536,556), IV 554 (555); patella I–IV 000; tibia I 3036 (3026,2036), II 3036 (3026), III 2022 (2032), IV 2023 (2022,2032,2033); metatarsus I 3035 (3033), II–III 3035, IV 3034 (3024,3014).

Measurements of palp and legs: Palp 10.2–12.8 [3.5–4.4, 1.5–1.8, 1.8–2.3, 3.4–4.3], I 48.0–58.6 [12.7–15.9, 3.7–4.9, 13.4–16.9, 12.6–14.8, 5.6–6.1], II 37.3–45.8 [10.3–13.6, 3.2–4.3, 10.3–12.5, 9.2–10.7, 4.3–4.8], III 26.8–32.3 [8.0–9.9, 2.3–3.2, 6.6–7.9, 6.6–7.8, 3.3–3.5], IV 38.2–47.1 [10.5–13.7, 2.9–3.8, 10.1–12.5, 10.0–11.9, 4.7–5.2]. Leg formula: 1423. FEM-I+MTT-I/CL=2.81–2.91, thus legs short in relation to females of other speciesgroups. The legs range within the spectrum listed in Bayer (2012, p. 96) for females of the sinensis -group.

Colouration of male and female (see also description for sinensis -group and Psechrus in Bayer 2012): Median bands on carapace hardly to slightly serrated, lateral bands hardly to slightly serrated and rather narrow (ca. 0.7–0.9 diameter of PME) or absent. Light longitudinal line ventrally on opisthosoma subdistally broken or if continuous, then subdistally constricted. Distal section (patch) broader than pre-subdistal section. Longitudinal line broad, width (measured centrally on opisthosoma) is 0.70–0.9x the width of one half of the cribellum.

Intraspecific variation of copulatory organs: Males: Intraspecific variation is low. The prolatero-distal part of embolus base differs slightly between SB 1236 ( Fig. 15 A), SB 1234 ( Fig. 15 C) and the holotype ( Bayer 2012, fig. 57b). The most proximal part of the tegulum may show an inconspicuous proximal bulge in retrolateral view ( Fig. 15 B, 26F). In SB 1236 and SB 1234 the central section of the tegulum seems slightly stouter than in the holotype. Consequently, in the former the subtegulum is more clearly visible beneath the tegulum ( Figs 15 A,C, 25F). Females: As illustrated in Bayer (2012, figs 58a, 58f) epigynes of this species are relatively variable in basic shape, sometimes broader and shorter (fig. 58a), sometimes rather slim and elongated (fig. 58f). The newly collected female shows an intermediate character state in this context ( Figs 16 A, 29B). The transversal section of the initial part of the copulatory duct that represents the dorsal part of the twisted section of the copulatory duct seems to be slightly broader in SB 1238 ( Fig. 16 B) than in the paratypes ( Bayer 2012, figs. 58b,g). Additionally the spermathecal head may exhibit a small outgrowth ( Fig. 16 B, left half of vulva).

Distribution. Vietnam ( Fig. 34 ).

Figures

FIGURE 15. Psechrus obtectus, males SB 1236, MHNG, (A – B) from Yen Tu, Quang Ninh Prov., Vietnam and SB 1234 (C) from Doi Ngo, Bac Giang Prov., Vietnam: left pedipalp. A, C. ventral, B. retrolateral view. C: Conductor; E: Embolus; EB: Embolus base; SD: Sperm duct; ST: Subtegulum; T: Tegulum.

FIGURE 16. Psechrus obtectus, female SB 1238, MHNG, from Yen Tu, Quang Ninh Prov., Vietnam: copulatory organ. A. Epigyne, ventral view. B. Vulva, dorsal view.

FIGURE 25. Psechrus spp., photographic images of male pedipalps, ventral view. A. Psechrus rani. B. Psechrus arietinus sp. nov. (only bulb shown). C. Psechrus jaegeri. D. Psechrus insulanus sp. nov.. E. Psechrus ampullaceus sp. nov.. F. Psechrus obtectus. A. SB 1232, MHNG, from Ba Vi, Ha Noi Prov., Vietnam. B. Paratype SB 1186, AMNH, from Tra My, Quang Nam Prov., Vietnam. C. SB 1248, SMF 64074, from That I-Tou, Champasak Prov., Laos. D. Holotype (SB 1247, MHNG) from Ko Surin Nua, Phang Nga Prov., Thailand. E. Paratype SB 1241, MHNG, from Sa Pa, Lao Cai Prov., Vietnam. F. SB 1236, MHNG, from Doi Ngo, Bac Giang Prov., Vietnam.

FIGURE 34. Distribution of some Psechrus spp. and of Fecenia protensa in continental Southeast Asia.