Micropholcus abha Huber & Meng 2024, sp. nov.
Creators: name: Huber, Bernhard A.
name: Meng, Guanliang
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Micropholcus
Micropholcus abha

description: Micropholcus abha Huber sp. nov.
Figs 3 E, 35, 36, 37, 38
Type material.
Holotype. Saudi Arabia – ‘ Asir • ♂; N of Abha; 18.4168 ° N, 42.4646 ° E; 2160 m a. s. l.; 21 Mar. 2024; B. A. Huber leg.; KSMA. Paratypes. Saudi Arabia – ‘ Asir • 4 ♂♂, 1 ♀, and 1 cleared ♀ abdomen; same collection data as for holotype; ZFMK Ar 24662.
Other material.
Saudi Arabia – ‘ Asir • 1 ♂, 3 ♀♀ (one abdomen transferred to ZFMK Ar 24662), in pure ethanol; same collection data as for holotype; ZFMK SA 111.
Diagnosis.
Distinguished from known congeners by presence of dorsal process on palpal femur (arrowed in Fig. 35 C; similar only in M. jacominae), by bipartite tip of dorsal hinged process of procursus (arrowed in Fig. 36 C), and by unique shapes of bulbal processes (Fig. 36 D, E; similar to M. dhahran sp. nov. but with unique retrolateral pointed process); from similar congeners of southern Saudi Arabia (M. abha sp. nov., M. harajah sp. nov., M. dhahran sp. nov.) also by hinged process of procursus without small proximal spine; from most congeners (except for three species above and M. jacominae and M. darbat sp. nov.) also by long trochanter apophysis (Fig. 35 C; longer than palpal femur). Female with unique lateral sacs in internal genitalia (arrows in Fig. 37 C); with distinct anterior arc as in similar congeners from southern Saudi Arabia (M. alfara sp. nov., M. harajah sp. nov., M. dhahran sp. nov.) but without distinct internal crescent-shaped structures (possible homologues visible between pore plates). From M. harajah sp. nov. also distinguished by absence of subdistal conical projection on hinged process of procursus (cf. Fig. 28 C) and by absence of pair of external epigynal pockets (cf. Fig. 30 A).
Description.
Male (holotype). Measurements. Total body length 2.4, carapace width 0.9. Distance PME - PME 195 µm; diameter PME 70 µm; distance PME - ALE 20 µm; distance AME - AME 25 µm; diameter AME 50 µm. Leg 1: 27.1 (6.8 + 0.4 + 6.8 + 11.9 + 1.2), tibia 2: 4.1, tibia 3: 2.5, tibia 4: 3.5; tibia 1 L / d: 85; diameters of leg femora (at half length) 0.085 –0.095; of leg tibiae 0.080.
Colour (in ethanol). Carapace pale ochre-yellow with large brown median mark divided medially, ocular area not darkened, clypeus slightly darkened; sternum monochromous whitish; legs pale ochre-yellow, patellae and tibia-metatarsus joints barely darkened, femur 1 proximally barely darkened; abdomen pale ochre-grey, dorsally and laterally with large whitish internal marks.
Body. Habitus as in Fig. 3 E. Ocular area slightly raised (distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.66 / 0.54), unmodified. Abdomen oval, approximately twice as long as wide.
Chelicerae. As in Fig. 37 A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs; with pair of very low proximal frontal humps; with prominent pair of proximal lateral processes.
Palps. As in Fig. 35; coxa unmodified; trochanter with very long ventral apophysis with distinct proximal bend and modified hair on distal tip; femur small relative to tibia, distally widened, with distinct ventral and dorsal humps; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 36 A – C) proximally with sclerotised prolateral hump; at half-length with prolateral-ventral sclerotised ridge transforming prolaterally into transparent membrane, and brush of dorsal hairs; distally with small retrolateral ridge and strong ventral apophysis, large membranous ventral-prolateral flap, and distinctive dorsal hinged process. Genital bulb (Fig. 36 D, E) with strong proximal sclerite; with two sclerotised processes of unclear homology: prolateral process with strong pointed cone directed towards bulbous part of genital bulb and with some hair-like extensions; retrolateral process originating from basis of embolus, heavily sclerotised with strong retrolateral pointed process and flattened distal apophysis; and mostly semi-transparent short embolus with fringed membranous tip.
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> 20 pseudosegments, distally distinct.
Variation (male). Tibia 1 in five males (incl. holotype): 5.9–6.8 (mean 6.3); clypeus in other males not or barely darkened.
Female. In general very similar to male; sternum margins slightly darkened. Tibia 1 in two females: 4.7, 5.2 (missing in other females). Epigynum (Fig. 38 A, B) slightly protruding, anterior plate oval, with long but transparent and indistinct knob-shaped process posteriorly; with pair of dark brown lateral sclerites, and median internal dark structure poorly visible through cuticle; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 37 C, 38 C, D) with pair of elongated pore plates in transversal position; with pair of lateral sclerites, pair of large distinctive lateral sacs, median ridges, and large membranous anterior arc.
Etymology.
The species name is derived from the type locality; noun in apposition.
Distribution.
Known from type locality only, in Saudi Arabia, ‘ Asir Province (Fig. 13 C).
Natural history.
The spiders were found in small caverns at rock outcrops in an open environment (Fig. 14 C), i. e., in less sheltered microhabitats than most other species.
description: Published as part of Huber, Bernhard A. & Meng, Guanliang, 2024, Old World Micropholcus spiders, with first records of acrocerid parasitoids in Pholcidae (Araneae), pp. 95-182 in ZooKeys 1213 on pages 95-182, DOI: 10.3897/zookeys.1213.133178