Pholcus krabi 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, pp. 1-55 : 28-30

Pholcus krabi Huber , sp. nov.

urn:lsid:zoobank.org:act:A078EA4B-89F1-4E10-8592-DF39683AFA43

Figs 102–105 , 111–123 , 134–136

Diagnosis

Distinguished from similar species (other species in the Ph. krabi group) by morphology of male palps ( Figs 111–112 ; unique shapes of small uncus and small appendix; distinctive procursus with prolateral process ending in heavily sclerotized tip) and by distinctive pair of small dark internal structures in internal female genitalia (arrow in Fig. 114 ).

Etymology

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

Type material

THAILAND: holotype, ♂, ZFMK ( Ar 15035 ), Krabi , Khao Phanom Bencha National Park, trails near headquarters (8°14.6' N, 98°55.0' E), 110 m a.s.l., domed webs among forest vegetation, 8 Mar. 2015 (B.A. Huber, B. Petcharad) .

Other material examined

THAILAND: 3 ♂♂, 4 ♀♀, ZFMK ( Ar 15036–37 ), same data as holotype ; 2 ♀♀, 4 juvs, in absolute ethanol, ZFMK ( Mal 338 ), same data ; 2 ♂♂, 5 ♀♀, ZFMK ( Ar 15038–39 ), Surat Thani, Khao Sok National Park, forest along nature trail (8°54.8' N, 98°29.3'– 98°30.5' E), domed webs among vegetation, 110–160 m a.s.l., 11–12 Mar. 2015 (B.A. Huber, B. Petcharad) ; 3 ♀♀, in absolute ethanol, ZFMK ( Mal 357 ), same data ; 2 ♂♂, 3 ♀♀, ZFMK ( Ar 15040 ), Ranong, Klong Nakha Wildlife Sanctuary (9°27.6' N, 98°30.7' E), 40 m a.s.l., forest, domed webs among vegetation, 12 Mar. 2015 (B.A. Huber, B. Petcharad) ; 3 ♀♀, in absolute ethanol, ZFMK ( Mal 363 ), same data .

Description

Male (holotype)

MEASUREMENTS. Total body length 4.1, carapace width 0.95. Leg 1: 34.8 (8.3 + 0.4 + 8.3 + 15.5 + 2.3), tibia 2: 5.2, tibia 3: 2.9, tibia 4: 4.5; tibia 1 L/d: 86. Distance PME-PME 375 µm, diameter PME 105 µm, distance PME-ALE ~35 µm; AME absent.

COLOR. Carapace pale ochre to whitish with small dark median mark, ocular area and clypeus with light brown pattern; sternum whitish; palps reddish; legs pale ochre to whitish with brown patellae and tibia-metatarsus joints; abdomen pale gray with very indistinct darker marks dorsally and laterally, monochromous ventrally.

BODY. Habitus as in Figs 102–103 ; ocular area slightly raised and each triad on short stalk directed laterad ( Fig. 116 ); carapace without median furrow; clypeus unmodified; sternum wider than long (0.60/0.48), unmodified. ALS with only two spigots (one widened, one pointed; Fig. 122 ).

CHELICERAE. As in Fig. 113 , with large proximal processes and pair of rounded distal apophyses without modified hairs ( Fig. 118 ).

PALPS. As in Figs 111–112 ; coxa unmodified; trochanter with long retrolatero-ventral apophysis directed first laterad then bending sharply ventrad ( Fig. 119 ); femur with small retrolatero-dorsal process; tibia large; procursus with distinctive prolateral process ending in heavily sclerotized tip ( Fig. 120 ), with sclerotized and membranous pointed processes ventrally; bulb with indistinct prolateral process, strong proximal sclerite, small uncus and small appendix ( Fig. 121 ), weakly sclerotized embolus.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 3%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 pseudosegments not seen in dissecting microscope. Tarsus 4 comb-hairs of the simplified Pholcus - type (cf. Huber & Fleckenstein 2008), with five lateral tines ( Fig. 123 ).

Male (variation)

Tibia 1 in 6 other males: 7.7–8.3 (mean 8.1).

Female

In general similar to male ( Figs 104–105 ) but eye triads on low humps and closer together ( Fig. 117 ; PME-PME distance: 220 µm); clypeus and ocular area frontally black; sternum anterior part slightly darker. Tibia 1 in 12 females: 6.3–7.3 (mean 6.8). Epigynum weakly sclerotized slightly bulging plate with semi-transparent posterior ‘knob’, internal anterior arch and distinctive small sclerites visible through cuticle ( Figs 114 , 134–135 ); internal genitalia as in Figs 115 and 136 , with straight anterior sclerite and oval pore plates.

Natural history

At Phanom Bencha, all eight specimens were collected from two bushes close to each other. Two days of intensive search in various parts of the forest did not result in any further specimens. At Khao Sok, all specimens were found in degraded forest close to the park road; none was found in well preserved forest.

Distribution

Known from three localities in southern Thailand ( Fig. 110 ).

Figures

Fig. 110. Known distribution of the Pholcus krabi species group.

Figs 102 – 109. Live specimens, Pholcus krabi Huber, sp. nov. (102 – 105), Ph. narathiwat Huber, sp. nov. (106 – 107), and Ph. kipungit Huber, sp. nov. (108 – 109). 102 – 104. ♂ and ♀ from Khao Sok, Thailand. 105. ♀ with egg-sac from Phanom Bencha, Thailand. 106 – 107. ♂ and ♀ from Hala Bala, Thailand. 108 – 109. ♂ and ♀ from Poring, Sabah.

Figs 111 – 115. Pholcus krabi Huber, sp. nov., ZFMK Ar 15036 – 37. 111 – 112. Left male palp, prolateral and retrolateral views. 113. Male chelicerae, frontal view. 114 – 115. Cleared female genitalia, ventral and dorsal views (arrow points at distinctive small dark internal structure). Abbreviations: a = appendix; b = genital bulb; e = embolus; p = procursus; u = uncus. Scale lines: 0.3 mm (113), 0.5 mm (111 – 112, 114 – 115).

Figs 116 – 123. Pholcus krabi Huber, sp. nov., ZFMK Ar 15038 – 39. 116 – 117. Male and female prosomata, frontal views. 118. Male distal cheliceral apophysis. 119. Left male palp, dorsal view. 120. Left procursus (and trochanter apophysis), retrolateral view. 121. Right bulbal processes, prolateral (slightly ventral) view. 122. Male ALS. 123. Comb-hairs on male tarsus 4. Abbreviations: a = appendix; b = genital bulb; e = embolus; f = femur; p = procursus; tr = trochanter; u = uncus. Scale lines: 8 µm (123); 10 µm (118, 122); 80 µm (121); 100 µm (120); 200 µm (116 – 117, 119).

Figs 134 – 142. Female genitalia, untreated in ventral view, cleared in ventral and dorsal views. 134 – 136. Pholcus krabi Huber, sp. nov. 137 – 139. Ph. narathiwat Huber, sp. nov. 140 – 142. Ph. kipungit Huber, sp. nov.