Pholcus khaolek Huber

Berhard A. Huber, Booppa Petchard, Charles Leh Moi Ung, Joseph K. H. Koh & Amir R. M. Ghazali, 2016, The Southeast Asian Pholcus halabala species group (Araneae, Pholcidae): new data from field observations and ultrastructure, European Journal of Taxonomy 190 (190), pp. 1-55 : 21-24

Pholcus khaolek Huber , sp. nov.

urn:lsid:zoobank.org:act:2A1CAF47-9EB4-480C-8C83-DFB0162AF617

Figs 52–53 , 63–78 , 99–101

Diagnosis

Easily distinguished from most similar known relative ( Ph. kuhapimuk sp. nov.) by morphology of male palps ( Figs 63–64 ; shapes of male palpal tarsus and procursus tip, larger uncus, complex appendix with retrolateral process) and by female internal genitalia ( Figs 66–67 ; distinctive median triangular sclerite). From other close relatives also by combination of pale coloration ( Figs 52–53 ), shape of male palpal trochanter apophysis (curved, proximally wide, distally pointed; Fig. 64 ), and shape and position of pore plates ( Fig. 67 ).

Etymology

The species name is derived from the type locality; noun in apposition.

Type material

THAILAND: holotype, ♂, ZFMK ( Ar 15028 ), Nakhon Si Thammarat, Khao Nan National Park, Tham Khao Lek (8°46.09' N, 98°43.68' E), 95 m a.s.l., on rock walls around cave, 10 Mar. 2015 (B.A. Huber, B. Petcharad) .

Other material examined

THAILAND: 6 ♂♂, 5 ♀♀, 2 juvs, ZFMK (5 ♂♂, 4 ♀♀, Ar 15029–30 ) and PSUZC (1 ♂, 1 ♀), same data as holotype ; 1 ♂, 2 ♀♀, 3 juvs, in absolute ethanol, ZFMK ( Mal 350 ), same data .

Description

Male (holotype)

MEASUREMENTS. Total body length 4.6, carapace width 1.3. Leg 1: 48.6 (11.6 + 0.6 + 11.7 + 22.8 + 1.9), tibia 2: 7.9, tibia 3: 4.5, tibia 4: 6.3; tibia 1 L/d: 95. Distance PME-PME 340 µm, diameter PME 125 µm, distance PME-ALE ~35 µm; distance AME-AME 50 µm; diameter AME 55 µm.

COLOR. Carapace pale ochre-yellow with pair of light brown marks posteriorly; ocular area and clypeus not darkened; sternum light brown with lighter marks and dark lateral margins; legs ochre-yellow with dark brown patellae and tibia-metatarsus joints; abdomen monochromous ochre-gray.

BODY. Habitus as in Fig. 53 ; ocular area slightly raised, with brushes of stronger hairs behind each PME ( Figs 68–69 ); carapace without median furrow; clypeus unmodified; sternum wider than long (0.84/0.52), unmodified. ALS with one widened, one pointed, and six smaller cylindrically shaped spigots of varying sizes ( Fig. 78 ).

CHELICERAE. As in Fig. 65 , with pair of distal frontal apophyses provided with two to three modified (cone-shaped) hairs each ( Fig. 70 ), pair of rounded lateral processes, and pair of small indistinct proximal frontal humps.

PALPS. As in Figs 63–64 ; coxa unmodified; trochanter with large retrolatero-ventral apophysis; femur proximally widened on ventral side, with small retrolatero-dorsal apophysis; tarsus without dorsal elongation; procursus rather simple ( Figs 71–72 ), with prolateral weakly sclerotized process and transparent membranous structures; procursus tip as in Fig. 75 ; bulb with distinctive uncus and appendix with retrolateral process ( Fig. 73 ); weakly sclerotized short embolus.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 6%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 with> 30 pseudosegments, distally fairly distinct. Tarsus 4 comb-hairs as in Fig. 71 .

Male (variation)

Tibia 1 in 5 other males: 10.1–12.8 (mean 11.7). Some males with white marks on abdomen.

Female

In general similar to male ( Fig. 52 ) but without stronger hairs behind PME; eye triads closer together than in male (PME-PME distance: 220 µm). Tibia 1 in 5 females: 8.7–10.1 (mean 9.3). Epigynum weakly sclerotized bulging area, only posterior area more strongly sclerotized, with small but distinct ‘knob’ ( Figs 66 , 77 , 99–100 ); internal genitalia as in Figs 67 and 101 , with anterior arch and distinctive triangular sclerite visible through cuticle.

Natural history

This species was abundant at the type locality on vertical and slightly overhanging smooth rocks. Specimens were observed tightly pressed against the rock surface, in some cases with a small domed web nearby. When disturbed, the spiders dropped to the ground.

Distribution

Known from type locality only ( Fig. 57 ).

Figures

Fig. 57. Known distributions of species tentatively assigned to the Pholcus halabala species group.

Figs 49 – 56. Live specimens, Pholcus kuhapimuk Huber, sp. nov. (49 – 51), Ph. khaolek Huber, sp. nov. (52 – 53), and Ph. sudhami Huber, 2011 (54 – 56). 49 – 51. ♂, penultimate instar ♂, and ♀ with egg-sac from Wat Kuhapimuk, Thailand. 52 – 53. ♀ with spiderlings and ♂ from Khao Lek, Thailand. 54 – 55. ♂ from Tham Phraya Nakhon, Thailand. 56. ♂ from Erawan, Thailand.

Figs 63 – 67. Pholcus khaolek Huber, sp. nov., ZFMK Ar 15029 – 30. 63 – 64. Left male palp, prolateral and retrolateral views. 65. Male chelicerae, frontal view. 66 – 67. Cleared female genitalia, ventral and dorsal views. Abbreviations: a = appendix; b = genital bulb; e = embolus; p = procursus; u = uncus. Scale lines: 0.5 mm.

Figs 68 – 78. Pholcus khaolek Huber, sp. nov., ZFMK Ar 15029 – 30. 68. Male ocular area, frontal view. 69. Modified hairs between male eye triads. 70. Male distal cheliceral apophysis (arrows point at modified hairs). 71. Right procursus, retrolateral view. 72. Left procursus, prolateral view. 73. Left bulbal processes, prolateral view. 74. Comb-hairs on male tarsus 4. 75. Tip of right procursus, retrolateral view. 76. Female prosoma, frontal view. 77. Epigynum, ventral view. 78. Male ALS. Abbreviations: a = appendix; b = genital bulb; e = embolus; p = procursus; tr = trochanter; u = uncus. Scale lines: 20 µm (70, 74, 78); 30 µm (69, 75); 80 µm (73); 100 µm (72); 200 µm (68, 71, 77); 400 µm (76).

Figs 90 – 101. Female genitalia, untreated in ventral view, cleared in ventral and dorsal views. 90 – 92. Pholcus ubin Huber, sp. nov. 93 – 95. Ph. lintang Huber, sp. nov. 96 – 98. Ph. kuhapimuk Huber, sp. nov. 99 – 101. Ph. khaolek Huber, sp. nov.