Psechrus aluco, Bayer, 2012

Bayer, Steffen, 2012, The lace-sheet-weavers — a long story (Araneae: Psechridae: Psechrus), Zootaxa 3379 (1), pp. 1-170 : 33-34

Psechrus aluco sp. nov.

Figs 13a–c , 87f , 90f

Type material: Holotype ♀ ( SB 123 ), INDONESIA: Java, Jawa Barat Province: Cibodas, Gunung Gedeh Nature Reserve , 1450 m; S. Djojosudharmo leg. 06.XII.1986; Deeleman Coll. in RMNH.

Etymology. The specific name refers to the copulatory openings including the surrounding area, which are reminiscent of the eyes of the tawny owl ( Strix aluco Linnaeus ); term “aluco” in apposition.

Diagnosis (see also diagnosis for annulatus -group above). Females similar to P. annulatus in having rounded copulatory ducts (CD). Distinguished by the distinctly smaller CD and by the spermathecal heads (SH), which are located posteriorly at spermathecae ( Fig. 13b ). Moreover, median septum (MS) protruding more strongly ( Fig. 13a ).

Description. Male: unknown.

Female (Note: both legs IV missing):

Body and eye measurements. Carapace length 5.1, carapace width 3.4, anterior width of carapace 2.2, opisthosoma length 7.3, opisthosoma width 3.8. Eyes: AME 0.32, ALE 0.37, PME 0.37, PLE 0.36, AME–AME 0.22, AME–ALE 0.06, PME–PME 0.21, PME–PLE 0.33, AME–PME 0.43, ALE–PLE 0.37, clypeus height at AME 0.75, clypeus height at ALE 0.55.

Cheliceral furrow with three promarginal and four retromarginal teeth.

Measurements of palp and legs. Leg formula:—. Palp: 6.2 [2.1, 0.8, 1.2, 2.1]; Legs: I 34.3 [9.5, 1.9, 9.5, 8.6, 4.8], II 27.0 [7.7, 1.7, 7.2, 6.6, 3.8], III 18.7 [5.7, 1.3, 4.4, 4.7, 2.6].

Palpal claw with 14 teeth.

Spination. Palp: 131, 110, 1101, 1013; legs: femur I 556, II 546 III 545; patella I–III 000; tibia I–II 3038, III 3124; metatarsus I–III 3035.

Copulatory organ (see also diagnosis and general description of annulatus -group). MS very large in comparison to epigynal field (EF), posteriorly ca. 1.5x broader than between the two copulatory openings (CO) ( Fig. 13a ). Slit sense organs and epigynal muscle sigilla outside EF. SH upon relatively short stalks ( Fig. 13b ).

Note: It can not be excluded, that the dark parts at or in CO ( Figs 13a , 87f ) are mating plugs. I carefully tried to remove them, but they were very rigid. In order to avoid damage of epigynal structures I did not try harder. However, equally possible that these structures are part of the copulatory organ.

Colouration (see also description for annulatus -group and Psechrus ). Width of lateral bands medium-sized (ca. 1.3x diameter of PME) and not serrated.

Distribution. Indonesia [Java] ( Fig. 100 ).

Figures

FIGURES 13a–c. Psechrus aluco sp. nov., ♀ holotype SB 123 from Indonesia, Java, Jawa Barat Prov. a Epigyne, ventral view. b Vulva, dorsal view. c Schematic course of internal duct system.

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 100. Distribution of Psechrus in eastern Malaysia and central Indonesia. Symbols (unicoloured): species belonging to the annulatus-group. Symbols (black, filled with light colour): species belonging to the mulu-group. Arrows: species belonging to the argentatus-group.