Micropholcus darbat 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 darbat

description: Micropholcus darbat Huber sp. nov.
Figs 4 A, B, 5 B, 6 D, E, 7 H, 8 A – C, 9 C, 10 C, D, 11 B, G, H, 52, 53, 54, 55
Micropholcus sp. n. Om 74 – Huber and Eberle 2021, Suppl. material 1.
Type material.
Holotype. Oman – Dhofar • ♂; Wadi Darbat; between 17.086 ° N, 54.444 ° E and 17.095 ° N, 54.452 ° E; 200–230 m a. s. l., 23 Feb. 2018; B. A. Huber leg.; ZFMK Ar 24671.
Other material.
Oman – Dhofar • 9 ♂♂, 7 ♀♀, 1 juv. (1 ♂, 1 ♀ used for SEM); same collection data as for holotype; ZFMK Ar 24672, 24699 • 1 ♂, 3 ♀♀, in pure ethanol; same collection data as for holotype; ZFMK Om 133 • 2 ♂♂, 2 ♀♀; Ain Athoom; 17.1185 ° N, 54.3667 ° E; 280 m a. s. l.; in small cave; 28 Feb. 2018; B. A. Huber leg.; ZFMK Ar 24673 • 1 ♂, 1 ♀, in pure ethanol; same collection data as for preceding; ZFMK Om 147 • 3 ♂♂, 1 ♀; near Qairoon Hairitti; 17.2600 ° N, 54.0808 ° E; 845 m a. s. l.; in small cave; 27 Feb. 2018; B. A. Huber leg.; ZFMK Ar 24674 • 2 ♀♀, in pure ethanol; same collection data as for preceding; ZFMK Om 146 • 3 ♂♂, 5 ♀♀, 1 juv.; Wadi Nahiz; 17.140 ° N, 54.123 ° E; 140 m a. s. l.; in small caverns; 26 Feb. 2018; B. A. Huber leg.; ZFMK Ar 24675 • 1 ♀, 3 juvs, in pure ethanol; same collection data as for preceding; ZFMK Om 142.
Diagnosis.
Males are easily distinguished from known congeners by shape of procursus with distinctive dorsal hinged process split into two branches (Fig. 53 C); also by shapes of bulbal processes (Fig. 53 D, E; prolateral apophysis simple, with small proximal prolateral hump) and cheliceral processes (Fig. 54 A, B; proximal frontal processes very low and indistinct); from geographically close M. shaat sp. nov. also by longer trochanter apophysis without distinct proximal process (Fig. 52 C). Females differ from known congeners by pair of internal pockets visible also in uncleared specimens (arrows in Fig. 55); from geographically close M. shaat sp. nov. also by epigynum without median sclerotised band (Fig. 55 A), pore plates oval and converging anteriorly (Fig. 55 C), and internal genitalia without large membranous sac.
Description.
Male (holotype). Measurements. Total body length 3.2, carapace width 1.2. Distance PME - PME 250 µm; diameter PME 90 µm; distance PME - ALE 20 µm; distance AME - AME 15 µm; diameter AME 55 µm. Leg 1: 36.5 (9.1 + 0.6 + 9.1 + 16.1 + 1.6), tibia 2: 5.9, tibia 3: 3.8, tibia 4: 5.1; tibia 1 L / d: 83; diameters of leg femora (at half length) 0.12–0.13; of leg tibiae 0.11.
Colour (in ethanol). Prosoma and legs pale ochre-yellow, carapace with brown median mark; legs with darkened patellae and tibia-metatarsus joints; abdomen pale grey to whitish.
Body. Habitus as in Fig. 4 A. Ocular area raised (distinct in frontal view; Fig. 5 B). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.75 / 0.60), unmodified. Abdomen oval, approximately twice as long as wide. Gonopore with four epiandrous spigots (Fig. 10 C).
Chelicerae. As in Figs 6 D, 54 A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs (Fig. 6 E); pair of proximal lateral processes weakly sclerotised and directed towards distal; and pair of very low proximal frontal humps.
Palps. As in Fig. 52; coxa unmodified; trochanter with long ventral apophysis with retrolateral hump at basis and modified hair at tip (Fig. 9 C); femur proximally with low dorsal hump, distally with weakly sclerotised rounded process on prolateral-ventral side; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Figs 7 H, 53 A – C) proximally with sclerotised prolateral hump; at half length with prolateral sclerotised ridge transforming distally into transparent membrane, and dense brush of dorsal hairs; distally with small retrolateral ridge, ventral apophysis directed towards prolateral, membranous ventral-prolateral flap (Fig. 8 A, B), and distinctive dorsal hinged process split into two branches. Genital bulb (Figs 8 C, 53 D, E) with strong proximal sclerite, prolateral sclerite simple with small proximal prolateral hump, simple retrolateral sclerite, and mostly semi-transparent short embolus.
Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs (most hairs missing in holotype but confirmed in males from near Qairoon Hairitti); retrolateral trichobothrium of tibia 1 at 6 %; prolateral trichobothrium absent on tibia 1; tarsus 1 with> 30 pseudosegments, distally distinct.
Variation (male). Tibia 1 in 16 males (incl. holotype): 6.9–9.2 (mean 8.2). Distance between eye triads 190–250 µm. Some males with white marks dorsally on abdomen.
Female. In general very similar to male but abdomen often much wider, ocular area slightly less raised and triads closer together (PME - PME 180–190 µm). Tibia 1 in 13 females: 5.7–7.1 (mean 6.3). Epigynum (Figs 10 D, 55 A) anterior plate oval, protruding, with membranous knob (Fig. 11 B) in posterior position and slightly directed towards anterior; lateral internal sclerites clearly visible in untreated specimens; posterior epigynal plate very short and indistinct. Internal genitalia (Fig. 54 C, 55 B, C) with pair of oval pore plates converging anteriorly, pair of lateral sclerites and pair of ventral pockets (arrows in Fig. 55); with sclerotised anterior arc.
Etymology.
The species name is derived from the type locality; noun in apposition.
Distribution.
Known from several localities in Dhofar, western Oman (Fig. 13 C).
Natural history.
In Wadi Darbat and Wadi Nahiz, the spiders were abundant on the vertical rocks and rock shelters lining the valleys. They were tightly pressed against the rock surface, making them difficult to spot. Upon disturbance, they ran away or dropped to the ground. Near Qairoon Hairitti, the spiders were collected in a small and shallow cave. At Ain Athoom, most specimens were found in a small cave, but juveniles were also found under rocks in the neighbouring area. Two egg sacs contained 21 and 27 eggs, respectively, with an egg diameter of 0.59 mm (Huber and Eberle 2021). One male had an acrocerid larva in his book lung (Fig. 76 E, F).
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