Pholcus buatong 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 : 38-43

Pholcus buatong Huber , sp. nov.

urn:lsid:zoobank.org:act:D2E21FAE-2ECD-414D-81E4-4C3CC7FC352F

Figs 143–146 , 154–168 , 184–186

Diagnosis

Easily distinguished from known congeners by morphology of male palps ( Figs 154–155 ; unique shape of procursus with transversal sclerotized ridges on retrolateral side and complex processes on prolateral side; slender appendix) and by internal female genitalia (large lateral sclerites; shape and position of pore plates; Figs 158 , 186 ). From most congeners (except putatively closest relatives Ph. satun and Ph. schwendingeri ) also by dorsally uniquely widened male palpal patella ( Fig. 155 ) and by large sclerotized ‘knob’ on female external genitalia ( Fig. 184 ).

Etymology

The species name is derived from one of the localities where this species was found; noun in apposition.

Type material

THAILAND: holotype, ♂, ZFMK ( Ar 15044 ), Krabi , near Khao Phanom Bencha National Park, Tham Khao Phueng (8°14.16’ N, 98°54.26’ E), 45 m a.s.l., on walls in cave, 8 Mar. 2015 (B.A. Huber, B. Petcharad) .

Other material examined

THAILAND: 9 ♂♂, 3 ♀♀, 1 juv., ZFMK (8 ♂♂, 2 ♀♀, Ar 15045 ) and PSUZC (1 ♂, 1 ♀), same data as holotype ; 2 ♂♂, 3 ♀♀, in absolute ethanol, ZFMK ( Mal 335 ), same data ; 3 ♂♂, 1 ♀, ZFMK ( Ar 15046 ), ~ 10 km N Krabi town, Tham Buatong (8°10.83' N, 98°53.06' E), 50 m a.s.l., on cave walls, 7 Mar. 2015 (B.A. Huber, B. Petcharad) ; 3 ♀♀, in absolute ethanol, ZFMK ( Mal 332 ), same data .

Description

Male (holotype)

MEASUREMENTS. Total body length 4.0, carapace width 1.0. Leg 1: 44.3 (10.4 + 0.4 + 10.5 + 21.2 + 1.8), tibia 2: 7.1, tibia 3: 4.2, tibia 4: 5.9; tibia 1 L/d: 120. Distance PME-PME 370 µm, diameter PME 90 µm, distance PME-ALE ~35 µm; AME absent.

COLOR. Carapace pale ochre-grey with light brown posterior mark, ocular area with small median and pair of lateral brown marks; clypeus not darkened; sternum pale gray with small very indistinct darker marks; legs ochre-yellow with darker brown patellae and tibia-metatarsus joints; abdomen ochre-gray with some black and indistinct whitish marks dorsally and laterally, monochromous ventrally.

BODY. Habitus as in Figs 143–144 ; ocular area slightly raised and each triad on short stalk directed obliquely dorsad ( Fig. 159 ); carapace without median furrow; clypeus unmodified; sternum wider than long (0.60/0.50), unmodified. Gonopore with four epiandrous spigots ( Fig. 167 ). ALS with one widened, one pointed, and six smaller cylindrically shaped spigots of varying sizes ( Fig. 166 ).

CHELICERAE. As in Fig. 156 , barely modified, very indistinct frontal humps.

PALPS. As in Figs 154–155 ; coxa unmodified; trochanter with long ventral apophysis and small hump at its basis; femur with small retrolatero-dorsal process proximally ( Fig. 162 ) and rounded protrusion ventrally; patella dorsally characteristically widened, resulting in an angle between femur and patella of ~120° (lateral view); procursus very distinctive and complex, with transversal sclerotized ridges on retrolateral side and complex processes on prolateral side ( Figs 162–164 ); bulb elongate, with strong proximal sclerite, slender and simple appendix ( Fig. 161 ), without uncus, with long weakly sclerotized embolus distally transparent.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 4%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 with> 20 pseudosegments, very indistinct. Tarsus 4 comb-hairs of the simplified Pholcus - type (cf. Huber & Fleckenstein 2008), with four lateral tines ( Fig. 168 ).

Male (variation)

Tibia 1 in 10 other males: 8.9–10.4 (mean 9.7).

Female

In general similar to male ( Fig. 145 ) but eye triads on low humps and closer together ( Fig. 160 ; PME-PME distance: 200 µm). Tibia 1 in 5 females: 6.4–8.5 (mean 7.3). Epigynum weakly sclerotized flat plate with large conspicuous sclerotized ‘knob’ ( Fig. 165 ), anterior arch and lateral internal sclerites visible through cuticle ( Figs 157 , 184–185 ); internal genitalia as in Figs 158 and 186 , with large lateral sclerites and oval pore plates in rather anterior position.

Natural history

At Buatong Cave, most specimens were found in barely visible domed webs close to the rock surface. Only one specimen had its body tightly pressed against the rock surface. At Khao Phueng Cave, specimens were abundant in the cave entrance area (again in very fine webs) but not deeper in the cave.

Distribution

Known from two neighboring localities in Krabi Province, southern Thailand ( Fig. 153 ).

Figures

Fig. 153. Known distributions of the Pholcus buatong species group (Malay Peninsula) and of the Pholcus andulau species group (northern Borneo).

Figs 143 – 152. Live specimens, Pholcus buatong Huber, sp. nov. (143 – 146), Ph. satun Huber, 2011 (147 – 149), and Ph. schwendingeri Huber, 2011 (150 – 152). 143 – 145. ♂♂ and ♀ from Tham Buatong, Thailand. 146. ♂ from Tham Khao Phueng, Thailand. 147 – 149. Adult ♂, penultimate instar ♂, and ♀ from Gunung Jerai, Malaysia. 150 – 151. ♂♂ from Khao Sok, Thailand. 152. ♀ with egg-sac, from Phanom Bencha, Thailand.

Figs 154 – 158. Pholcus buatong Huber, sp. nov., ZFMK Ar 15045. 154 – 155. Left male palp, prolateral and retrolateral views (arrow points at whitish membranous structure). 156. Male chelicerae, frontal view. 157 – 158. Cleared female genitalia, ventral and dorsal views. Abbreviations: a = appendix; b = genital bulb; e = embolus; p = procursus. Scale lines: 0.3 mm (156), 0.5 mm (154 – 155, 157 – 158).

Figs 159 – 168. Pholcus buatong Huber, sp. nov., ZFMK Ar 15045. 159 – 160. Male and female prosomata, frontal views. 161. Left male palp, prolateral view. 162 – 164. Right male palp, retrolatero-dorsal, dorsal, and retrolateral views. 165. Epigynum, ventral view. 166. Male ALS. 167. Male gonopore. 168. Combhairs on male tarsus 4. Abbreviations: a = appendix; b = genital bulb; e = embolus; p = procursus; pa = patella; tr = trochanter. Scale lines: 20 µm (166, 168); 40 µm (167); 200 µm (159 – 165).

Figs 184 – 192. Female genitalia, untreated in ventral view, cleared in ventral and dorsal views. 184 – 186. Pholcus buatong Huber, sp. nov. 187 – 189. Ph. satun Huber, 2011. 190 – 192. Ph. schwendingeri Huber, 2011.