Psechrus singaporensis Thorell, 1894

Bayer, Steffen, 2012, The lace-sheet-weavers — a long story (Araneae: Psechridae: Psechrus), Zootaxa 3379 (1), pp. 1-170 : 37-41

Psechrus singaporensis Thorell, 1894

Figs 15a–i , 16a–f , 81e , 84h , 87h , 90h

Psechrus singaporensis Thorell 1894: 321 (Description of ♀). [Holotype ♀ (SB 90) from SINGAPORE (No further details); 1890–1891; Workman Collection No. 1052; 222; (Returned by Thorell 13.XI.1894); NMI 1901•144, examined]. Workman 1896: 78, figs 78a–g (Illustration of ♀). Thorell 1897: 103 (Sub ‘ singoriensis ’, presumably typo and not on purpose). Flower 1901: 45. Simon 1901: 47. Simon 1906: 287 (Synonymy with P. torvus [sub ‘ Nota ’], not considered by subsequent authors). Kulczyṅski 1908: 567. Lehtinen 1967: 261. Levi 1982: 125, description and illustration of ♂♂ and ♀♀, ad part, figs 42–43, 48–53 misidentified, figs 42–43 = Psechrus sp. singaporensis -group excluding singaporensis [♂ from MALAYSIA: Pahang Province, Genting; deposited in MC] (figs 40–41, 44–47: Illustration of ♂ and ♀♀). Murphy 1986: 66. Koh 1989: 77. Deeleman-Reinhold 2001: 38, fig. 16 (illustration of habitus of s.a. ♀). Song et al. 2002: 373. Bayer and Jäger 2010: 61, figs 24–25 (Illustration of ♀).

Psechrus torvus — Simon 1906: 287 (Record of ♀ from Singapore [sub ‘ Nota ’], misidentified).

Psechrus curvipalpis Fage 1929: 358 , figs 1–4 (Description and illustration of ♂ and ♀). [Syntypes: 2 ♂♂ (SB 506–507), 3 ♀♀ (SB 499–500, 502), 9 s.a. ♀♀ (SB 493–498, 503–505), 4 juvs (SB 489–492), all from MALAYSIA: Selangor Province: Batu caves (N of Kuala Lumpur); C. Dover leg. VII.1926; MNHN AR174/177, all type material examined]. Lehtinen 1967: 261 (Syn. with P. libelti , rejected by subsequent authors). Robinson and Lubin 1979: 149. Levi 1982: 125 (Syn.).

Additional material examined (1 ♂, 9 ♀♀, 1 s.a. ♂, 2 s.a. ♀♀, 4 juvs). MALAYSIA: Penang Province: Penang ; S.S. Flower leg. 1896 ; 1 ♂ ( SB 223 ), NHM . Pahang Province: Kampung Kuala Tembeling , N 4°04', E 102°19'; V. and B. Roth leg. 21.–24. IV.1990 ; 2 ♀♀ ( SB 977–978 ), CAS 9032232 . Selangor Province: Batu caves (N of Kuala Lumpur); Clark leg.; Coll. C.F. Roewer (1962) ; 1 ♀ ( SB 83 ), 2 s.a . ♀♀ ( SB 84–85 ), 4 juvs ( SB 866–869 ), SMF 13913. Selangor (no further details); Coll. R. Sherriffs; ‘ Tilg. 27-9-1962 ’; 1 ♀ ( SB 864 ), ZMUC 5731 . Kuala Lumpur Province: Kuala Lumpur ; collected before 1967; ‘4576(a)’; 1 s.a. ♂ (SB 1161, with developed bulb structures visible through the cuticle), AMNH . INDONESIA: Sumatra, Sumatera Utara Province: Sibolga; Acquisition: 1987 ; 1 ♀ ( SB 334 ), NHMW . SINGAPORE: No further details; Workman Collection No. 532; 1901 ; 2 ♀♀ ( SB 132–133 ), NMI 1901˙144. No further details about locality; no data about collector and collecting date ; 1 ♀ ( SB 520 ), MNHN AR172. Bukit Timah Nature Reserve , N 1°21'08'', E 103°46'29''; S. Huber leg. 02. IV.2009 ; Reared from juvenile, dead 21.VII.2009 ; 1 ♀ ( SB 220 ), SMF .

Doubtful material examined. MALAYSIA: Selangor Province: Gombak Forest Reserve , 15 km N of Kuala Lumpur, 245 m; 12.XI.1960 ; H. Exline - W. Peck- Collection (donated to CAS 1985 ); 1 juv. ( SB 979 ), CAS 9032231 . INDONESIA: Sumatra, Sumatera Utara Province: Bohorok (ca. 60 km W of Medan), Gunung Leuser National Park , primary dipterocarp rainforest, riverside; S. Djojosudharmo leg. 15.–17.XI.1983 ; 1 ♀ ( SB 113 ), 2 s.a. ♀♀ ( SB 559 , 561 ), 3 juvs ( SB 560 , 562–563 ), Deeleman Coll. in RMNH .

Revised diagnosis (see also diagnosis for singaporensis -group above). In males embolus (E) in ventral view broader than in P. elachys sp. nov. and its tip not as clearly pointed ( Figs 15b , 16a ) as in P. elachys sp. nov. E erected not as steep as in elachys sp. nov. and thus pointing less distally, but rather prolaterally ( Figs 15b , 16a ). Embolus base (EB) in alignment with retrolateral tegulum (T)-margin ( Figs 15b , 16a ). In retrolateral view E uniformly shaped and continuously converging from basal to distal section ( Figs 15c , 16b ). Females similar to P. elachys sp. nov. in having a rather simple median septum (MS) and medium sized copulatory ducts (CD) with spermathecal heads (SH) located upon distal section of CD ( Figs 15e–f,h–i , 17d–e ). Distinguished by the larger, slightly elongated copulatory openings (CO), leading to a different course of CD ( Fig. 15g cf. Fig. 17f ). CD slightly broader and longer ( Figs 15f,h ) than in P. elachys sp. nov.

Description. Male:

Body and eye measurements. Carapace length 4.4–6.6, carapace width 3.4–4.9, anterior width of carapace 1.7–2.3, opisthosoma length 5.7–9.2, opisthosoma width 2.0–4.0. Eyes: AME 0.26–0.43, ALE 0.31–0.45, PME 0.29–0.46, PLE 0.32–0.42, AME–AME 0.14–0.19, AME–ALE 0.06–0.09, PME–PME 0.16–0.23, PME–PLE 0.25–0.36, AME–PME 0.31–0.44, ALE–PLE 0.33–0.35, clypeus height at AME 0.54–0.72, clypeus height at ALE 0.41–0.55.

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

Measurements of palp and legs. Leg formula: 1423. Palp: 5.4–6.9 [1.9–2.5, 1.0–1.3, 0.8–1.0, 1.7–2.1]; Legs: I 52.5–79.0 [14.6–20.8, 2.1–3.3, 14.4–21.7, 14.7–24.3, 6.7–8.9], II 38.5–60.4 [10.9–16.4, 1.7–3.0, 10.0–15.8, 10.6–18.3, 5.3–6.9], III 25.7–40.3 [7.4–11.7, 1.3–2.1, 6.1–10.2, 7.2–11.5, 3.7–4.8], IV 42.1–63.3 [12.2–17.6, 1.6–2.5, 10.2–16.2, 12.1–19.7, 6.0–7.3].

Spination. Palp: 131 (132), 010, 0010(spine very small); legs: femur I 545 (656), II 556 III 545 (555), IV 544 (554); patella I–IV 000; tibia I–II 3038, III 3236 (3136), IV 3236 (3136); metatarsus I–III 3035, IV 3036 (3035).

Palpal femur modified with rounded ventral bulge ( Fig. 15d ). MC-I and MT-I: present, but not as distinctly developed as in P. himalayanus Simon, 1906 .

Copulatory organ (see also diagnosis and general description for singaporensis -group). Conductor (C) distally broader than proximally ( Fig. 15b ), in lateral view narrow, arising subdistally at medial section of T ( Figs 15a,b ). Palpal tibia in lateral view distally clearly broader than proximally ( Figs 15a,c ).

Female: (Measurements of holotype first, those of other specimens as range in parentheses; in holotype distal limbs of legs I and III missing).

Body and eye measurements. Carapace length 4.3 (4.3–7.0), carapace width 2.9 (2.9–4.9), anterior width of carapace 1.7 (1.7–2.7), opisthosoma length 6.7 (6.7–11.3), opisthosoma width 2.8 (2.6–6.9). Eyes: AME 0.28 (0.27–0.43), ALE 0.38 (0.36–0.49), PME 0.38 (0.36–0.48), PLE 0.38 (0.36–0.47), AME–AME 0.17 (0.14–0.20), AME–ALE 0.10 (0.04–0.10), PME–PME 0.23 (0.15–0.23), PME–PLE 0.26 (0.25–0.38), AME–PME 0.39 (0.36–0.50), ALE–PLE 0.32 (0.26–0.40), clypeus height at AME 0.68 (0.73–0.81), clypeus height at ALE 0.46 (0.48–0.67).

Cheliceral furrow with three promarginal and four retromarginal teeth.

Measurements of palp and legs. Leg formula: 1423. Palp: 5.9 (5.3–7.8) [2.0 (1.8–2.6), 0.8 (0.8–1.1, 1.1 (1.0–1.5), 2.0 (1.8–2.6)]; Legs: I—(34.9–50.1) [10.1 (9.7–13.8), 1.7 (1.7–2.9), 10.3 (9.5–13.7, – (9.2–12.8), – (4.7–6.9)], II 29.5 (27.2–37.4) [7.9 (7.6–10.8), 1.6 (1.6–2.5), 6.8 (6.8–10.0), 8.3 (7.5–9.8), 4.9 (3.6–5.3)], III – (17.4–26.8) [5.7 (5.2–8.0), – (1.1–1.9), – (4.2–6.7), – (4.5–6.8), – (2.4–3.4)], IV 31.7 (27.7–39.9) [8.9 (7.9–11.5), 1.4 (1.4–2.2), 7.6 (7.1–10.2), 8.7 (7.1–10.3), 5.1 (4.5–5.7)].

Palpal claw with 14 (14–15) teeth.

Spination. Palp: 131 (131,141), 110 (110), 1101 (1101), 1014 (1014); legs (—except for patella— variable, only most common states noted): femur I 655 (655,556), II 556 (566,546) III 545 (545,555), IV 554 (554,555,556); patella I–IV 000; tibia I 3038 (3038), II 3036 (3036,3038), III – (3136,3134), IV 3134 (3134,3136); metatarsus I – (3035), II 3035 (3035,3037), III – (3035), IV 3034 (3034).

Copulatory organ (see also diagnosis and general description of singaporensis -group). MS mostly more or less trapeze-like ( Figs 15i , 87h ). Slit sense organs and epigynal muscle sigilla outside epigynal field (EF). CD mostly with ½ winding until reaching receptaculum ( Figs 15h , 90h ), at least two times longer than diameter of receptaculum.

Primordial copulatory organ. Pre-epigyne: Pre-septum ca. 2 times broader than long ( Fig. 16c ), pre-EF separated in two parts. Long and narrow pre-copulatory openings already recognisable ( Fig. 16c ).

Pre-vulva: Pre-copulatory ducts anterio-medially curved ( Fig. 16d ), not larger than pre-receptacula.

Colouration of male and female (see also description for singaporensis -group and Psechrus ). Median bands on carapace not serrated. Width of lateral bands medium-sized (ca. 1.2x diameter of PME) and not (or barely) serrated.

Variation of copulatory organs. Males: E varies slightly in length ( Figs 15b–c , 16a–b ). Orientation of C may slightly differ ( Fig. 16a ). Distal part of T in SB 223 larger (in comparison to basal part) ( Fig. 16a ). In females the shape of MS varies distinctly ( Figs 15e,i , 16e ). In some specimens lateral margins of MS more or less parallel ( Fig. 15e ). Moreover, in some specimens MS posteriorly distinctly broader than anteriorly, in between CO ( Fig. 16e ). Length of EF differs among specimens examined ( Figs 15e,i , 16e , 87h ). CD may have winding for only 1/3 of length until reaching receptaculum ( Fig. 16f ). SH in some specimens somewhat larger ( Fig. 15f ).

Remarks: The species P. libelti , P. annulatus and P. curvipalpis were synonymised with P. singaporensis by Levi (1982). I do not agree with the synonymies of the two former species (see respective species descriptions herein), but with the synonymy of P. curvipalpis . According to copulatory organs the curvipalpis -females from Batu Caves, Malaysia ( Figs 15e,f ) correspond with the females from Singapore, including the holotype of P. singaporensis ( Figs 15h–i ). Differences in MS fall into the range of intraspecific variation (see above). Consequently, Fage (1929) was the first, who (even though unwittingly) described the male of P. singaporensis .

Levi (1982: 124, figs 42–43) illustrated a ♂ from Genting, Pahang Province, Malaysia, which he determined as P. singaporensis . The respective specimen is deposited in the F. & J. Murphy Collection (MC). According to Levi’s very accurate illustrations there are clear differences to the ♂ of P. singaporensis . Such differences can not be explained by intraspecific variation. Unfortunately the respective specimen was not available on request. I assume that it is a representative of the singaporensis -group. As long as there are no females available from the same locality, it is impossible to ascertain if this male belongs to a new species or if it is conspecific with P. norops sp. nov., from which only the female is known.

Deeleman-Reinhold (2001) shows an illustration of the dorsal habitus of a subadult female of Psechrus and identifies it as P. singaporensis (most likely due to the locality it was recorded). However, the colour pattern of carapace and opisthosoma is the same as similar species of the singaporensis -group, so the respective specimen may not necessarily be P. singaporensis . Even species of the annulatus -, mulu - or argentatus -group show a very similar colour pattern (of the carapace and legs). It should also be noted that the colour pattern of the opisthosoma of Psechrus is variable and dependant on its condition (e.g. before or after feeding). In Psechrus an identification to species level (as far as conventional methods are regarded and no other material from the respective locality is available) is only possible by checking the copulatory organs.

Distribution. Malaysia, Singapore, Indonesia [Sumatra] ( Fig. 99 ).

Figures

FIGURES 15a–i. Psechrus singaporensis. a–d ♂ SB 507, e–g ♀ SB 499 (both syntypes of P. curvipalpis) from Malaysia, Selangor Prov. h–i ♀ holotype SB 90 from Singapore. a–c ♂ palp (a prolateral, b ventral, c retrolateral view). d ♂ left palpal femur, retrolateral view. e, i Epigyne, ventral view. f, h Vulva, dorsal view. g Schematic course of internal duct system.

FIGURES 16a–f. Psechrus singaporensis. a–b ♂ SB 223 from Malaysia, Penang Prov. c–d s.a. ♀ SB 493 (syntype of P. curvipalpis) from Malaysia, Selangor Prov. e–f ♀ SB 334 from Indonesia, Sumatra, Sumatera Utara Prov. a–b ♂ palp (a ventral, b retrolateral view). c Pre-epigyne, ventral view. d Pre-vulva, dorsal view. e Epigyne, ventral view. f Vulva, dorsal view.

FIGURES 17a–g. Psechrus elachys sp. nov., from Thailand, Satun Prov. a–c, g ♂ paratype SB 862. d–f ♀ holotype SB 861. a–c ♂ palp (a prolateral, b ventral, c retrolateral view). g ♂ left palpal femur, retrolateral view. d Epigyne, ventral view. e Vulva, dorsal view. f Schematic course of internal duct system.

FIGURES 81a–j. Psechrus spp., photos of dorsal habitus (a–d) and ventral view of opisthosoma (e–j). a P. ancoralis. b P. hartmanni sp. nov. c P. sp. out of mulu-group. d P. luangprabang. e P. singaporensis. f P. annulatus. g P. jaegeri sp. nov. h P. marsyandi. i P. kunmingensis. j P. tauricornis sp. nov. a ♀ SB 75 from Laos, Luang Prabang Prov. b ♀ holotype SB 1007 from Sri Lanka, Central Prov. c ♂ from Malaysia, Borneo, Sarawak Prov. d ♀ SB 508 from Laos, Luang Nam Tha Prov. e s.a. ♀ SB 559 from Indonesia, Sumatera Utara Prov. f ♀ paralectotype SB 830 from Indonesia, Jawa Barat Prov. g ♀ holotype SB 530 from Laos, Champasak Prov. h s.a. ♀ SB 748 from Nepal, Dhawalagiri Prov. i ♀ SB 953 from China, Yunnan Prov. j ♀ SB 633 from Sri Lanka. Photos 81a by Helmut Steiner, Hanau, 81c by Peter Koomen, Leeuwarden (copyright owner).

FIGURES 84a–i. Psechrus spp., photos of left ♂ palp, ventral view. a P. argentatus. b–c P. libelti. d P. kinabalu. e P.mulu. f P. ulcus sp. nov. g P. decollatus sp. nov. h P. singaporensis. i P.elachys sp. nov. a ♂ SB 1107 from Papua New Guinea. b s.a. ♂ syntype SB 339 from Indonesia, Sumatera Selatan Prov. c ♂ SB 203 from Thailand, Song Khla Prov. d ♂ holotype SB 237 from Malaysia, Borneo, Sabah Prov. e ♂ holotype SB 242 from Malaysia, Borneo, Sarawak Prov. f ♂ holotype SB 141 from Indonesia, Kalimantan Selatan Prov. g ♂ paratype SB 857 from Indonesia, Jawa Timur Prov. h ♂ SB 507 (syntype of P. curvipalpis) from Malaysia, Selangor Prov. i ♂ paratype SB 862 from Thailand, Satun Prov.

FIGURES 87a–k. Psechrus spp., photos of epigyne, ventral view. a P. argentatus. b P. libelti. c P. mulu. d P. borneo. e P. annulatus. f P. aluco sp. nov. g P. decollatus sp. nov. h P. singaporensis. i P. elachys sp. nov. j P.norops sp. nov. k P. arcuatus sp. nov. a ♀ SB 608 from Indonesia, Maluku Prov. b ♀ SB 969 from Brunei Darussalam. c ♀ paratype SB 239 from Malaysia, Borneo, Sarawak Prov. d ♀ holotype SB 279 from Indonesia, Kalimantan Timur Prov. e ♀ lectotype SB 829 from Indonesia, Jawa Tengah Prov. f ♀ holotype SB 123 from Indonesia, Jawa Barat Prov. g ♀ holotype SB 501 from Indonesia, Jawa Timur Prov. h ♀ SB 864 from Malaysia, Selangor Prov. i ♀ holotype SB 861 from Thailand, Satun Prov. j ♀ holotype SB 860 from Malaysia, Pahang Prov. k ♀ holotype SB 333 from Indonesia, Sumatera Barat Prov.

FIGURES 90a–k. Psechrus spp., photos of vulva, dorsal view. a P. argentatus. b P. libelti. c P. mulu. d P. borneo. e P. annulatus. f P. aluco sp. nov. g P. decollatus sp. nov. h P. singaporensis. i P. elachys sp. nov. j P.norops sp. nov. k P. arcuatus sp. nov. a ♀ SB 551 from Papua New Guinea, Morobe Prov. b ♀ SB 87 from Indonesia, Sumatra, Mentawei Islds. c ♀ SB 253 from Malaysia, Borneo, Sarawak Prov. d ♀ holotype SB 279 from Indonesia, Kalimantan Timur Prov. e ♀ lectotype SB 829 from Indonesia, Jawa Tengah Prov. f ♀ holotype SB 123 from Indonesia, Jawa Barat Prov. g ♀ holotype SB 501 from Indonesia, Jawa Timur Prov. h ♀ SB 220 from Singapore. i ♀ holotype SB 861 from Thailand, Satun Prov. j ♀ holotype SB 860 from Malaysia, Pahang Prov. k ♀ holotype SB 333 from Indonesia, Sumatera Barat Prov.

FIGURE 99. Distribution of Psechrus in western Malaysia and Sumatra. Symbols: species belonging to the singaporensis- group. Arrow: Distribution of P. libelti (argentatus-group).