Psechrus ghecuanus Thorell 1897
Creators: name: Bayer, Steffen
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Psechridae
Psechrus
Psechrus ghecuanus

description: Psechrus ghecuanus Thorell, 1897
Figs 37a–g, 38a–f, 39a–h, 40a–d, 82e, 85j, 88k, 91k
Psechrus ghecuanus Thorell 1897: 101 (Description of s.a. ♀). [Syntypes: 2 s.a. ♀♀ (SB 221–222) from MYANMAR (BIRMA): Kayin Province: Ghecu, Mt. Carin (presently near Dedako), ca. N 19°17', E 96°42'30'', 500–1000 m; Leonardo Fea leg. 1885–1889; Thorell det. 20.X.1896; Thorell Coll. No. 68; Mus. civ. Gen. ded.; NRS; 1 p. s.a. ♀ (SB 772) with same data as above; ZMUC 13112; 1 p. s.a. ♀ (SB 773) with same data as above; ZMH, all type material examined]. Pocock 1900: 211. Kulczyṅski 1908: 567. Berland and Berland 1914: 133. Fage 1929: 360. Lehtinen 1967: 260 (Syn. with Psechrus torvus, rejected by subsequent authors). Levi 1982: 123, figs 29–33, ad part, figs 32–33 misidentified (Description of ♀, figs 29–31: illustration of s.a. ♀ and ♀). Yin et al. 1985: 19, figs 1A–I (Description of ♂ and ♀, illustration of ♂ and ♀). Song et al. 1999: 397, figs 232A–B, M–N (Illustration of ♂ and ♀). Wang and Yin 2001: 333, figs 5–8 (Description of ♂ and ♀, illustration of ♂ and ♀). Jäger 2007: 45. Sebastian and Peter 2009: 528.
Additional material examined (6 ♂♂, 8 ♀♀, 7 s.a. ♂♂, 5 s.a. ♀♀, 4 juvs). MYANMAR: Kayin Province: Tenasserim, Mulayit Taung (Mt. Mooleyit), 1600–1900 m; L. Fea leg. 1885–1889; T. Thorell det. 1898; 2 ♀♀ (SB 820–821, checked via photos of dorsal and ventral habitus and epigyne, kindly provided by Pakawin Dankittipakul), MCSN. LAOS: Luang Nam Tha Province: Muang Sing, Nam Det, N 21°10'11.6'' – 21°09'59'', E 101°14'26.7'' – 101°14'44.5'', 820–1100 m, secondary forest, along path; P. Jäger & V. Vedel leg. 06.XI.2004; 3 s.a. ♀♀ (SB 2, 837–838), 4 s.a. ♂♂ (SB 832–835), 3 juvs (SB 60, 836, 839), SMF. Vieng Phoukha, N of V.P., N 20°41'36.9'', E 101°02'17.5'', ca. 700 m, between villages, slope at wayside; P. Jäger leg. 05. III.2008; 2 ♂♂ (SB 28, 36), 5 ♀♀ (SB 29–31, 37, 39), 1 s.a. ♀ (SB 37, with fully developed adult epigyne underneath cuticle) SMF. THAILAND: Mae Hong Son Province: Sop Pong, Tham Lot Cave (8 km N of S.P.), ca. N 19°34', E 98°18'; V. & B. Roth leg. 05.–11. III.1990; 1 ♂ (SB 780), 2 s.a. ♂♂ (SB 779, 781), USNM. Chiang Mai Province: Chiang Mai District, Mae Rim (near Chiang Mai), secondary Ficus forest on a ridge of hill, in a small tree hole; H. Ono leg. 14.X.2009 as immature, reared, adult III.2010; 1 ♂ (SB 613), NSMT. Chiang Mai District, Doi Suthep-Pui National Park, N 18°48'46'', E 98°56'34'', 450 m, evergreen rainforest; P. Schwendinger leg. 30.XII.2009; 1 s.a. ♂ (SB 421), SMF. Chiang Rai Province: Phan District, Doi Luang National Park, Poo Kaeng Waterfalls, 500 m, 50 m W of WF, trail through evergreen forest; P. Dankittipakul leg. 20. II.2007; 1 ♂ (SB 207), 1 s.a. ♀ (SB 208), MHNG. Lam Pang Province: Ban Dong District, Tham Pha Thai, 300 m, secondary forest in front of cave entrance; P. Dankittipakul leg. 24.VI.2002; 1 ♀ (SB 201), 1 juv. (SB 786), SMF. Lamphun Province: Mae Tha District, Doi Khuntan National Park, 750 m; P. Schwendinger leg. 30.I.1997; 1 ♂ (SB 145), MHNG.
Doubtful material examined. MYANMAR: Sagaing Province: Alaungdaw Kathapa National Park, Log Cabin, N 22°19'08'', E 94°28'32''; J. Coddington & R. Babtista leg. 20.–25.X.1998; 1 p. s.a. ♀ (SB 774), 4 juvs (SB 775–778), USNM. CHINA: Yunnan Province: Baoshan Prefecture, Bawan, N 24°57', E 98°50', 950 m, weedy vegetation and road cuts; C. Griswold & D. Kavanaugh leg. 08.XI.1998; 2 s.a. ♀♀ (SB 957–958), 1 p. s.a. ♂ (SB 956), CAS 9023974.
Revised diagnosis (see also diagnosis for himalayanus -group above). Males similar to P. pakawini sp. nov. in having a quite strongly sclerotised, semicircular extension apically on tegulum (T) (see asterisk in Fig. 39g). Distinguished by the shorter embolus (E) and conductor (C) (the former with proximal section in ventral view compress) and the less proximally extending sperm duct (Fig. 37b). Moreover, E arising distal to arising point of C. Females similar to P. pakawini in shape of epigyne and vulva. Distinguished by the margins of lateral lobes (LL), which are at most 100° curved anteriorly and point medially (Fig. 37d) or at least almost medially, and by the shorter copulatory ducts (should be viewed from frontal, Fig. 37g) extending less medially.
Description. Male:
Body and eye measurements. Carapace length 6.2–9.4, carapace width 4.4–7.3, anterior width of carapace 2.3–3.3, opisthosoma length 7.7–12.9, opisthosoma width 2.6–5.1. Eyes: AME 0.32–0.38, ALE 0.35–0.46, PME 0.39–0.47, PLE 0.37–0.47, AME–AME 0.13–0.17, AME–ALE 0.04–0.06, PME–PME 0.22–0.28, PME–PLE 0.24–0.35, AME–PME 0.53–0.57, ALE–PLE 0.38–0.54, clypeus height at AME 0.69–0.99, clypeus height at ALE 0.58–0.93.
Cheliceral furrow with three promarginal and four retromarginal teeth.
Measurements of palp and legs. Leg formula: 1423. Palp: 7.8–10.4 [2.9–3.7, 1.3–2.1, 1.2–1.5, 2.4–3.1]; Legs: I 46.0–61.3 [12.0–16.9, 2.8–4.4, 12.4–16.6, 12.8–16.4, 6.0–7.0], II 37.5–49.1 [10.0–14.3, 2.6–3.9, 9.8–12.9, 10.2–12.6, 4.9–5.4], III 26.3–34.3 [7.6–10.2, 2.0–3.1, 6.4–8.1, 6.9–8.8, 3.4–4.1], IV 39.5–51.3 [10.5–14.7, 2.4–3.6, 9.9–12.6, 11.3–14.0, 5.4–6.4].
Spination (most common pattern, the second most common state in parentheses).
Palp: 131, 110 (010), 1101 (0000); legs: femur I 566 (666), II–III 555, IV 555 (565); patella I–IV 000; tibia I–II 3038, III 3034 (3134), IV 3036 (3034); metatarsus I 3035 (4035,4037), II–IV 3035.
Palpal femur without modification, broadest distally (Fig. 39d).
Copulatory organ (see also diagnosis and general description for himalayanus -group). Conductor slightly Sshaped medially, with flat protrusion subdistally (Figs 37a–c). Tegulum in lateral view apically pointed (Figs 37a,c, 39f,h). Palpal tibia in lateral view short to medium sized (Figs 37a,c). Cymbium dorsally without scopula.
Female:
Body and eye measurements. Carapace length 8.1–11.2, carapace width 5.5–7.8, anterior width of carapace 3.2–4.4, opisthosoma length 10.2–13.1, opisthosoma width 4.7–7.5. Eyes: AME 0.38–0.46, ALE 0.42–0.51, PME 0.47–0.53, PLE 0.46–0.53, AME–AME 0.20–0.29, AME–ALE 0.07–0.08, PME–PME 0.24–0.38, PME–PLE 0.40–0.48, AME–PME 0.71–0.81, ALE–PLE 0.52–0.64, clypeus height at AME 0.92–1.14, clypeus height at ALE 0.86–1.13.
Cheliceral furrow with three promarginal and four retromarginal teeth.
Measurements of palp and legs. Leg formula: 1423. Palp: 9.4–11.2 [3.1–4.0, 1.4–1.8, 1.8–2.0, 3.1–3.4]; Legs: I 47.3–53.6 [13.1–15.1, 3.6–4.6, 12.8–14.7, 12.3–13.4, 5.5–5.8], II 39.2–44.8 [11.4–13.3, 3.2–4.2, 10.2–11.6, 9.9–10.8, 4.5–4.9], III 28.2–32.3 [8.6–9.8, 2.6–3.3, 6.8–7.6, 6.9–7.8, 3.3–3.8], IV 40.1–46.0 [11.6–13.3, 2.8–3.6, 10.2–11.8, 10.3–12.0, 4.9–5.3]. Thus, legs in females, in relation to other Psechrus species, short: FEM-I+MTT-I/ CL: 2.5–3.1.
Palpal claw with 12–15 teeth.
Spination. Palp: 131, 110, 1101, 1014; legs: femur I 566 (556,667), II 566, III–IV 555; patella I–IV 000; tibia I–II 3038, III 3036 (3035,3026), IV 3036; metatarsus I–III 3035, IV 3035 (3024).
Copulatory organ (see also diagnosis and general description of himalayanus -group). Epigyne with bulges in the regions of the CO. Median septum with fine transversal ridge with both ends curved anteriorly (Fig. 37d). Slit sense organs and epigynal muscle sigilla outside epigynal field (EF). Anterior to epigyne many slightly curved wrinkles.
Primordial copulatory organ. Pre-epigyne: In general shape cross rectangular (Figs 38a–b,d) and similar to P. pakawini sp. nov. Distinguished by the presence of an imhomogeneous pre-EF consisting of two parts (Figs 38a–b,d).
Pre-vulva: Pre-vulva similar to P. pakawini sp. nov. Distinguished by the further developed pre-SH (Fig. 38c).
Pre-pre-epigyne (Fig. 38f) resembles already the pre-epigyne, but pre-pre-EF (Fig. 38f) far less distinct than pre-EF (Fig. 38b).
Pre-pre-vulva: Less structured (Fig. 38e) than pre-vulva.
Colouration of male and female (see also description for himalayanus -group and Psechrus). Median bands on carapace serrated (Fig. 82e). Some specimens with narrow, dark extensions connecting them (median bands) with the lateral bands. Lateral bands narrow (ca. diameter of PME) and serrated (Fig. 82e). Light longitudinal line ventrally on opisthosoma continuous, its width medium-sized. If measured centrally on opisthosoma, its width is less than the width of one half of the cribellum (ca. 0.5–0.8 of one half of the cribellum).
Variation of copulatory organs. In males E and C may be a bit longer (Figs 39a–c) than is generally found (Figs 37a–c). Direction of semicircular extension of T slightly differs (Figs 37b, 39b,e,g). Females: Distal parts of margins of LL may be extending less medially (Fig. 40c). MS may be slightly longer (Fig. 40a). In vulva SH may be longer (Fig. 40b) than is generally found (Figs 37e, 40d).
Remarks: Levi (1982) was the first to illustrate the female copulatory organ of this species. He examined an adult female from Doi Suthep, Thailand and considered it conspecific with the subadult syntypes of P. ghecuanus. As a reason for that, he stated that “The leg proportions were identical...” and “...the recording localities of the mature females from Thailand are close to the type locality in Burma ” (Levi 1982). In the present study eight females and five subadult females were examined. In some cases subadults and adults from exactly the same recording locality. In one case (SB 37) a subadult female was close to adult moult and the epigyne was already fully developed underneath the old cuticle. The pre-epigynes of all five subadults corresponded to those of the syntypes. Moreover, Thorell himself identified adult females from (the present) Kayin Prov., Myanmar sub P. ghecuanus. This material still exists, was examined for the present study (see SB 820–821 in material list, above) and the epigynes corresponded to the ones of the other females examined herein. So the females examined in Levi (1982, figs 30–31), Yin et al. (1985), Song et al. (1999), Wang and Yin (2001) and in the present study unambiguously belong to P. ghecuanus. Yin et al. (1985) first described and illustrated the male of P. ghecuanus. They identified female Psechrus specimens collected together with —at that time— unknown males from Southern China as P. ghecuanus by using the revision of Levi (1982). In the present study (among others) material from Chiang Rai Province, Thailand was checked, a subadult female and an adult male from exactly the same locality. As the subadult female could be identified as P. ghecuanus, it is certain, that the males examined in Yin et al. (1985), in Song et al. (1999), in Wang and Yin (2001) and in the present study unambiguously belong to P. ghecuanus.
Distribution. Myanmar, China, Laos, Thailand (Fig. 98).
description: Published as part of Bayer, Steffen, 2012, The lace-sheet-weavers — a long story (Araneae: Psechridae: Psechrus), pp. 1-170 in Zootaxa 3379 (1) on pages 75-80, DOI: 10.11646/zootaxa.3379.1.1, http://zenodo.org/record/6039832