Savarna Huber, 2005

Huber, Bernhard A., Petcharad, Booppa & Bumrungsri, Sara, 2015, Revision of the enigmatic Southeast Asian spider genus Savarna (Araneae, Pholcidae), European Journal of Taxonomy 160, pp. 1-23 : 2-4

Genus Savarna Huber, 2005

Savarna Huber, 2005: 76–77 . Type species: S. thaleban Huber, 2005 .

Diagnosis

Medium sized (~ 2–3 mm total body length), six-eyed spiders, with round to oval abdomen and relatively long legs ( Figs 2–13 ). Distinguished from similar genera ( Spermophora Hentz, 1841 ; Khorata Huber, 2005 ; Aetana Huber, 2005 ) by having the long male palpal trochanter apophysis uniquely attached to the femur ( Figs 15 , 21 , 48 , 57 , 66 , 82 ), and by the male cheliceral armature (laterally projecting proximal cheliceral apophyses and no further modiFcation; Figs 16 , 45 , 55 , 63 , 83 ). It furthermore differs from Spermophora by the absence of epigynal pockets, the absence of epiandrous spigots ( Figs 26 , 52 , 71 ) and the reduction of AMS spigots to two ( Figs 24 , 53 , 61 , 70 ).

Amendments to original description

Male distance PME-PME 185–255 µm. Male clypeus either with brushes of hairs ( S. kraburiensis ; Fig. 45 ), with paired processes at rim ( S. kaeo sp. nov.; S. thaleban ; S. miser ; Figs 20 , 55 ), or with median process at rim ( S. tessellata ; Fig. 63 ). Abdomen consistently with dark and white marks (the monochromous abdomen of the male holotype of S. baso – dating from 1913 – is probably an artifact). Male leg 1 ~9–10 × body length; tibia 2 either slightly longer than tibia 4 or of same length. Legs either without spines ( S. thaleban ; S. miser ), with spines on femora 1 ( S. kraburiensis ; S. tessellata ), or with spines on femora 1–2 and tibiae 1–3 ( S. kaeo sp. nov.). Male tibiae with higher than usual density of short vertical hairs. Retrolateral trichobothrium on male tibia 1 at 7–9% of tibia 1 length. Tarsus 4 with single ventral row of comb-hairs ( Figs 51 , 62 , 69 ). Male gonopore without epiandrous spigots (all species examined except S. miser ; Figs 26 , 52 , 71 ). ALS with only two spigots each (all species examined except S. miser ; Figs 24 , 53 , 61 , 70 ).

Monophyly and relationships

Previously, the monophyly of Savarna was supported mainly by two unique morphological characters, the modiFcations of the male chelicerae and of the male palpal trochanter ( Huber 2005). Preliminary analyses of molecular data of all known species (A. Valdez-Mondragón, B.A. Huber, D. Dimitrov, unpubl. data) strongly support the monophyly of Savarna .

The single ventral row of comb-hairs on the fourth tarsus places the genus in Pholcinae (cf. Huber & Fleckenstein 2008). The morphology of the comb-hairs (‘ Belisana -type’ sensu Huber & Fleckenstein 2008) suggests the genus is not part of the Pholcus group of genera. Preliminary analyses of molecular data strongly support this ‘basal’ position in Pholcinae. Detailed relationships with other genera among ‘basal’ Pholcinae remain obscure. The absence of epiandrous spigots is rare in Pholcinae and is otherwise known only in Khorata Huber, 2005 (B.A. Huber, unpubl. data on three species), in Spermophorides Wunderlich, 1992 (B.A. Huber, unpubl. data on one species), and in two undescribed species of unknown afFnity from Borneo (B.A. Huber, unpubl. data). Our preliminary molecular analyses do weakly support a close relationship among some of these taxa.

Natural history

Even though Savarna spiders also occur outside caves, all known localities are closely associated with limestone caves. Both inside and outside the caves, the spiders build domed webs close to the ground with at least one side of the web attached to the rock surface. Web diameter ranges from about 10 to 25 cm. When disturbed, the spiders vibrate; if disturbance continues or is strong, they drop to the ground and remain motionless for a while (cf. Fig. 7 ). Egg-sacs are covered by a sparse layer of barely visible silk and contain about 20– 30 eggs (cf. Fig. 13 ). For data on individual species, see descriptions below.

Composition

The genus now includes Fve species, all of which are treated below.

Distribution

Savarna appears to be restricted to southern Thailand, mainland Malaysia, and Sumatra ( Fig. 1 ; but see Addendum).

Key to species

1. Carapace without lateral marks ( Figs 12 , 75 ) ……………………………………………………2

– Carapace with dark lateral marks ( Figs 2, 6 ) ……………………………………………………3

2. Male clypeus with single median process ( Fig. 63 ); genital bulb with two processes in opposing directions ( Fig. 65 ); male palpal tibia unusually slender ( Huber 2005: Fg. 138); epigynum posterior margin projecting medially ( Figs 32 , 72 ) …… S. tessellata ( Simon, 1901)

– Male clypeus with pair of rounded processes at rim (similar to S. kaeo sp. nov., cf. Fig. 20 ); bulb with single process ( Figs 79 , 81 ); male palpal tibia ‘normal’, i.e., not unusually slender ( Fig. 81 ); epigynum posterior margin without median projection ( Figs 34 , 84 ) … S. miser ( Bristowe, 1952)

3. Male genital bulb with two long processes in opposing directions ( Fig. 50 ); epigynum with prominent median process ( Fig. 54 ) ………… S. kraburiensis Wongprom & Wiwatwitaya, 2015

– Male genital bulb with only one process or with much shorter processes ( Figs 14 , 22 , 60 ); epigynum without median process ( Figs 28–31 ) ………………………………………………4

4. Male palpal procursus strongly curved ( Huber 2005: Fg. 132); male clypeus with very indistinct pair of lateral processes at rim ( Fig. 55 ); epigynum evenly curved, without lateral posterior humps ( Figs 30–31 ) ……………………………………………………… S. thaleban Huber, 2005

– Male palpal procursus weakly curved ( Fig. 15 ); male clypeus with distinct pair of lateral processes at rim provided with hair brushes ( Fig. 20 ); epigynum with pair of lateral humps near posterior rim ( Figs 27–29 ) ………………………………………………………… S. kaeo sp. nov.

Figures

Fig 1. Known distribution of the genus Savarna; but see Addendum.

Figs 2 – 7. Live specimens. — 2 – 4. Savarna kaeo sp. nov. ƋƋ from Reclining Buddha Cave and from Tham Sai (2, 4); ♀ with eggsac from Tham Sai (3). — 5 – 7. S. kraburiensis Wongprom & Wiwatwitaya, 2015. Ƌ, ♀ with eggsac, and ♀ with eggsac after dropping to the ground; all from Tham Phra Kayang.

Figs 8 – 13. Live specimens. — 8 – 10. Savarna thaleban Huber, 2005. ƋƋ and ♀ with eggsac; all from Thaleban National Park. — 11 – 13. S. tessellata (Simon, 1901). ƋƋ and ♀ with eggsac; all from Tham Meud.

Figs 14 – 18. Savarna kaeo sp. nov. 14 – 15. Left male palp, prolateral and retrolateral views (b = genital bulb; bp = bulbal process; pr = procursus; tr = trochanter). 16. Male chelicerae, frontal view. 17 – 18. Cleared female genitalia, ventral and dorsal views. Scale bars: 16 = 0.3 mm; 14 – 15, 17 – 18 = 0.5 mm.

Figs 19 – 27. Savarna kaeo sp. nov. 19 – 20. Male prosoma, frontal and oblique frontal views. 21. Right male palpal trochanter (tr) and femur, retrolateral view. 22. Left procursus (pr) and bulbal process (bp), prolatero-distal view (b = bulb). 23. Right procursus (pr) and bulbal process (bp), retrolatero-distal view (b = bulb). 24. Female ALS. 25. Male palpal tarsal organ. 26. Male gonopore. 27. Epigynum, ventrolateral view. Scale bars: 24 – 25 = 10 µm; 26 = 80 µm; 21 – 23 = 100 µm; 19 – 20, 27 = 200 µm.

Figs 44 – 54. Savarna kraburiensis Wongprom & Wiwatwitaya, 2015. 44. Male prosoma, frontal view. 45. Male clypeus and chelicerae, oblique frontal view. 46. Female prosoma, frontal view. 47. Trichobothrium on female palpal tibia. 48. Right male palpal trochanter (tr) and femur, prolateral view. 49. Right procursus, prolatero-distal view. 50. Right procursus (pr) and genital bulb (b), prolaterodistal view (bp = bulbal processes). 51. Comb-hair on female left tarsus 4, prolateral view. 52. Male gonopore. 53. Female ALS. 54. Epigynum, ventral view (arrow points at median process). Scale bars: 47, 51 = 10 µm; 53 = 20 µm; 52 = 60 µm; 49 = 100 µm; 45, 48, 50, 54 = 200 µm; 44, 46 = 300 µm.

Figs 55 – 62. Savarna thaleban Huber, 2005. 55 – 56. Male and female prosomata, frontal views. 57. Right male palpal trochanter (tr), prolateral view. 58. Left procursus, ventro-distal view. 59. Right procursus, prolateral view. 60. Right genital bulb (b) and bulbal process (bp); arrow points at sperm duct opening. 61. Female ALS. 62. Comb-hair on female right tarsus 4, prolateral view. Scale bars: 61 – 62 = 10 µm; 57, 60 = 100 µm; 55 – 56, 58 – 59 = 200 µm.

Figs 63 – 71. Savarna tessellata (Simon, 1901). 63 – 64. Male and female prosomata, frontal views (arrow points at clypeus process). 65. Left genital bulb (b), retrolateral view (bp = bulbal process). 66. Right male palpal trochanter (tr), prolateral view. 67. Right procursus tip, prolateral view. 68. Left procursus tip, retrolateral view. 69. Comb-hair on male right tarsus 4, prolateral view. 70. Male ALS. 71. Male gonopore. Scale bars: 69 – 70 = 10 µm; 71 = 50 µm; 66 – 68 = 100 µm; 63 – 65 = 200 µm.

Figs 81 – 85. Savarna miser (Bristowe, 1952). 81 – 82. Left male palp, prolateral and retrolateral views (b = genital bulb; bp = bulbal process; pr = procursus; tr = trochanter; asterisks = broken tibia). 83. Male chelicerae, frontal view. 84 – 85. Cleared female genitalia, ventral and dorsal views. Scale bars: 83 = 0.3 mm; 81 – 82, 84 – 85 = 0.5 mm.

Figs 74 – 80. Savarna miser (Bristowe, 1952). 74. Ƌ from Batu Caves, dorsal view. 75 – 76. ♀ from Batu Caves, prosoma in dorsal and lateral views. 77 – 78. Right procursi, retrolateral views, ƋƋ from Batu Caves (77) and from cave near Baso (holotype of Spermophora baso Roewer, 1963; 78). 79 – 80. Right bulbal processes, ƋƋ from Batu Caves (79) and from cave near Baso (holotype of Spermophora baso Roewer, 1963; 80). At varying scales.

Figs 28 – 35. Epigyna, ventral and lateral views. — 28 – 29. Savarna kaeo sp. nov. — 30 – 31. S. thaleban Huber, 2005. — 32 – 33. S. tessellata (Simon, 1901). — 34 – 35. S. miser (Bristowe, 1952). At varying scales.

Figs 72 – 73. Savarna tessellata (Simon, 1901). Cleared female genitalia, ventral and dorsal views. Scale bar: 0.5 mm.