Pholcus buatong

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, pp. 1-55 : 38

Pholcus buatong species group

This species group is newly proposed to include one species previously part of the Ph. halabala group ( Ph. satun Huber, 2011 ), one species previously tentatively assigned to the Pholcus ethagala group ( Ph. schwendingeri Huber, 2011 ), and a newly described species ( Ph. buatong Huber , sp. nov.). They share three putative synapomorphies, (1) the complete reduction of distal anterior apophyses on the male chelicerae ( Fig. 156 ); (2) the very distinctive dorsal bulging of the male palpal patella ( Fig. 155 ; angle between femur and patella ~120–125° rather than ~180° as in typical pholcids); and (3) the large, heavily sclerotized ‘knob’ on the epigynum ( Figs 184, 187, 190 ). The group is strongly supported by preliminary molecular data (A. Valdez-Mondragón, B.A. Huber & D. Dimitrov unpublished data). Pholcus schwendingeri and Ph. buatong sp. nov. also share a distinctive whitish membranous process retrolatero-distally on the procursus (arrows in Figs 155 , 180 ). Otherwise this group appears rather inhomogeneous: Pholcus schwendingeri males have extremely long eye stalks ( Fig. 173 ) while males of the other two species have short eye stalks ( Fig. 155 ); Pholcus buatong sp. nov. is rock-dwelling while the other two species are leaf litter dwelling; Pholcus satun has small AME, while the other two species lack AME; Pholcus satun males have only one bulbal process (sclerotized embolus), while males of the other two species have a membranous embolus plus an appendix. In all three species, egg-sacs are carried in front of the body ( Figs 145, 152 ) as in typical pholcids. This species group is known from southern Thailand and northern mainland Malaysia ( 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 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 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.

Figs 173 – 183. Pholcus schwendingeri Huber, 2011, ZFMK Ar 15051 – 52. 173 – 174. Male prosoma, oblique and frontal views. 175. Female prosoma, frontal view. 176. Male eye triad. 177. Process between male eye stalks. 178 – 179. Right genital bulb and procursus, prolateral and dorsal views. 180. Left palp, retrolateral view (arrow points at whitish membranous structure). 181. Male gonopore. 182. Epigynum, ventral view. 183. FemaleALS. Abbreviations: a = appendix; b = genital bulb; e = embolus; p = procursus; tr = trochanter. Scale lines: 10 µm (183); 20 µm (177); 50 µm (181); 80 µm (176); 200 µm (175, 178 – 180, 182); 400 µm (173 – 174).

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.