Micropholcus shaat Huber, 2024

Huber, Bernhard A. & Meng, Guanliang, 2024, Old World Micropholcus spiders, with first records of acrocerid parasitoids in Pholcidae (Araneae), ZooKeys 1213, pp. 95-182 : 95-182

publication ID	https://doi.org/ 10.3897/zookeys.1213.133178
publication LSID	lsid:zoobank.org:pub:B8E6EE1A-023D-4B64-8D3A-C1843F0D8376
DOI	https://doi.org/10.5281/zenodo.13841468
persistent identifier	https://treatment.plazi.org/id/03BCF62A-51BC-46EF-9CA1-FC2B8720C36C
taxon LSID	lsid:zoobank.org:act:03BCF62A-51BC-46EF-9CA1-FC2B8720C36C
treatment provided by	ZooKeys by Pensoft
scientific name	Micropholcus shaat Huber
status	sp. nov.

Treatment

Micropholcus shaat Huber sp. nov.

Figs 4 C View Figure 4 , 56 View Figure 56 , 57 View Figure 57 , 58 View Figure 58 , 59 View Figure 59

Type material.

Holotype. Oman – Dhofar • ♂; Shaat sinkhole , in wadis leading to sinkhole; 16.774 ° N, 53.587 ° E; 850 m a. s. l.; 25 Feb. 2018; B. A. Huber leg.; ZFMK Ar 24676 . GoogleMaps

Other material.

Oman – Dhofar • 4 ♂♂, 2 ♀♀, 1 juv.; same collection data as for holotype; ZFMK Ar 24677 GoogleMaps • 1 ♀, 1 juv.; same collection data as for holotype but 24 Feb. 2018; ZFMK Ar 24678 GoogleMaps • 3 ♀♀, in pure ethanol; same collection data as for holotype but 24–25 Feb. 2018; ZFMK Om 137 GoogleMaps .

Diagnosis.

Males are easily distinguished from known congeners by several details of male palp (Figs 56 View Figure 56 , 57 View Figure 57 ; proximal process on trochanter; slender femur without distinct processes; procursus with simple dorsal hinged process; prolateral sclerite on genital bulb simple and slender). Females are easily distinguished from known congeners by anterior position of epigynal ‘ knob’ (Fig. 58 C View Figure 58 ), by distinctive sclerotised band medially on epigynal plate (Fig. 59 A View Figure 59 ), and by presence of large membranous sac in internal genitalia (Fig. 59 D View Figure 59 ); from geographically close M. darbat sp. nov. also by larger and wider pore plates (Fig. 58 C View Figure 58 ).

Description.

Male (holotype). Measurements. Total body length 2.6, carapace width 0.9. Distance PME - PME 260 µm; diameter PME 85 µm; distance PME - ALE 15 µm; distance AME - AME 20 µm; diameter AME 45 µm. Leg 1: 27.3 (6.8 + 0.5 + 6.9 + 11.7 + 1.4), tibia 2: 4.3, tibia 3: 2.6, tibia 4: 3.6; tibia 1 L / d: 81; diameters of leg femora (at half length) 0.09–0.10; of leg tibiae 0.08–0.09.

Colour (in ethanol). Prosoma and legs ochre-yellow, carapace with brown median mark; leg femora 1 and 2 proximally darkened; legs with darkened patellae and tibia-metatarsus joints; abdomen pale ochre-grey.

Body. Habitus as in Fig. 4 C View Figure 4 . Ocular area raised (distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.65 / 0.50), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 58 A, B View Figure 58 ; with pair of distal apophyses near laminae, each with two cone-shaped hairs; pair of lateral, indistinct, weakly sclerotised humps; and pair of distinct proximal frontal apophyses.

Palps. As in Fig. 56 View Figure 56 ; coxa unmodified; trochanter with long ventral apophysis with distinct proximal process directed towards coxa; femur slender, distally widened, with indistinct ventral hump at half length; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 57 A – C View Figure 57 ) proximally with sclerotised prolateral hump; at half length with prolateral sclerotised ridge transforming distally into transparent membrane, and brush of dorsal hairs; distally with small retrolateral ridge, bifid membranous ventral-prolateral flap, and distinctive dorsal hinged process. Genital bulb (Fig. 57 D, E View Figure 57 ) with strong proximal sclerite, prolateral process simple and slender, and short embolus proximally sclerotised, distally with transparent extensions.

Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs; retrolateral trichobothrium of tibia 1 at 6 %; prolateral trichobothrium absent on tibia 1; tarsus 1 with> 25 pseudosegments, distally distinct.

Variation (male). Tibia 1 in five males (incl. holotype): 6.2–7.8 (mean 6.8). Distance between eye triads 250–270 µm. Some males with white marks dorsally on abdomen.

Female. In general very similar to male but abdomen often wider, ocular area slightly less raised and triads closer together (PME - PME 200 µm). Tibia 1 in five females: 5.2–5.6 (mean 5.3). Epigynum (Fig. 59 A View Figure 59 ) anterior plate roundish, anterior margin weakly curved, posterior margin strongly curved, with distinctive median sclerotised band, membranous knob at anterior end of sclerotised band, directed towards posterior; lateral internal sclerites clearly visible in untreated specimens; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 58 C View Figure 58 , 59 B – E View Figure 59 ) with pair of large sclerotised pore plates, with roughly square-shaped sclerotised opening leading into large round membranous sac (collapsed in Fig. 59 D View Figure 59 ; removed in Fig. 59 B, C, E View Figure 59 ); with complex system of lateral membranous structures.

Etymology.

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

Distribution.

Known from type locality only, in Dhofar, western Oman (Fig. 13 C View Figure 13 ).

Natural history.

The spiders were found in niches and small caverns in the walls of the wadis leading to Shaat sinkhole (Fig. 14 E View Figure 14 ). They rested in the apex of very fine and poorly visible dome-shaped webs directly on the rock surface.