Old World species are long-legged, eight-eyed pholcids with an oval abdomen (Figs 3, 4); New World species are more variable, sometimes without AME, sometimes with elongate to worm-shaped abdomens. Most known species (except M. bukidnon sp. nov.) with unique modified hair at tip of male palpal trochanter apophysis (Fig. 9A–D; see also Huber 2000: figs 105, 106; Huber and Wunderlich 2006: figs 4h, 8d; Huber 2011: fig. 95; Huber et al. 2014: figs 32, 57). Male chelicerae with frontal apophyses with modified hairs (Fig. 6), i.e., similar to putative sister genus Cantikus Huber but different from other close relatives (Leptopholcus Simon, Pehrforsskalia Deeleman-Reinhold & van Harten, and Micromerys Bradley). Procursus and bulb morphology highly variable and not diagnostic at genus level (contra Huber 2011). Females not diagnosable morphologically at genus level (highly variable and similar to closely related genera).

Figure 3. 

Micropholcus Deeleman-Reinhold & Prinsen; live specimens from Saudi Arabia A M. dhahran Huber, sp. nov., male from ‘Asir, W of Dhahran Al Janub B M. harajah Huber, sp. nov., female with egg-sac from ‘Asir, SE of Harajah C, D M. alfara Huber, sp. nov., male and female with egg-sac from ‘Asir, S of Al Fara E M. abha Huber, sp. nov., male from ‘Asir, N of Abha F M. tanomah Huber, sp. nov., male from ‘Asir, NW of Tanomah G M. bashayer Huber, sp. nov., female with egg-sac from ‘Asir, NW of Al Bashayer H M. maysaan Huber, sp. nov., male from Mecca, NW of Maysaan. Photographs BAH.

Figure 4. 

Micropholcus Deeleman-Reinhold & Prinsen; live specimens from Oman, Morocco, and the Philippines A, B M. darbat Huber, sp. nov., male and female with egg-sac from Oman, Dhofar, near Qairoon Hairitti C M. shaat Huber, sp. nov., male from Oman, Dhofar, Shaat sinkhole D, E M. agadir (Huber), male and female with egg-sac from Morocco, Souss-Massa, Paradise Valley F M. ghar Huber, sp. nov., male from Morocco, Fès-Meknès, Kef El Ghar G M. khenifra Huber, Lecigne & Lips, sp. nov., male from Morocco, Béni Mellal-Khénifra, near Sidi Ben Daoud H M. bukidnon Huber, sp. nov., male from Philippines, Mindanao, Blue Water Cave. Photographs BAH.

Most parts in this general section about Micropholcus refer to the entire genus. The following description is limited to Old World taxa because they are relatively homogeneous, while some New World species (in particular those on the Caribbean islands) are superficially extremely different from South American (in particular Brazilian) and Old World species.

(Old World taxa). Male. Measurements. Total body length ~ 2.3–3.9. Carapace width 0.8–1.5. Diameter PME 60–100 µm; diameter AME usually 35–55 µm, in M. bukidnon sp. nov. only 15 µm. Tibia 1 length 5.0–10.2. Tibia 1 L/d: 57–85. Leg formula 1243. Diameters of leg femora (at half length) 80–150 µm, of leg tibiae 75–120 µm.

Colour (in ethanol). Prosoma and legs pale ochre-yellow to grey, carapace with dark pattern, legs with darker patellae and tibia-metatarsus joints; abdomen ochre-grey to whitish, monochromous or with whitish marks. Live specimens (Figs 3, 4) similar in colour but slightly darker.

Body. Ocular area slightly raised (distinct in frontal view; Fig. 5). Carapace without thoracic groove. Clypeus unmodified. Sternum slightly wider than long, unmodified. Abdomen approximately twice as long as wide. Gonopore with four (rarely five) epiandrous spigots (Fig. 10; see also Huber 2000: fig. 123; Huber 2011: fig. 99). ALS with one strongly widened spigot, one long pointed spigot, and six cylindrical spigots (Fig. 9; see also Huber 2000: figs 158, 159; Huber 2011: fig. 100); PMS with two conical spigots; PLS without spigots.

Figure 5. 

Micropholcus Deeleman-Reinhold & Prinsen; SEM images of prosomata (frontal views) and tips of female palps (dorsal views) A M. tanomah Huber, sp. nov.; female B M. darbat Huber, sp. nov.; male C, D M. ghar Huber, sp. nov.; male and female E, F M. bukidnon Huber, sp. nov.; male and female; note small AME G M. tanomah Huber, sp. nov., left palp H M. ghar Huber, sp. nov., right palp. Scale bars: 100 µm (A–D); 200 µm (E, F); 10 µm (G, H).

Chelicerae. Chelicerae with pair of strong frontal apophyses provided with conical or globular, strongly sculptured modified hairs (Fig. 6; see also Huber 2011: fig. 98), usually with one or two pairs of proximal processes; without stridulatory files.

Figure 6. 

Micropholcus Deeleman-Reinhold & Prinsen; SEM images of male chelicerae: distal apophyses with modified hairs and total view (D) A, B M. alfara Huber sp. nov. C M. tanomah Huber, sp. nov. D, E M. darbat Huber, sp. nov. F, G M. ghar Huber, sp. nov. H M. bukidnon Huber, sp. nov. Scale bars: 10 µm (A–C, F–H); 100 µm (D); 2 µm (E).

Palps. Palpal coxa unmodified. Trochanter with retrolateral-ventral apophysis usually with distinctive modified (short cylindrical) hair at tip (Fig. 9A–D), modified hair absent in M. bukidnon sp. nov. Femur variable in shape, often with rounded processes (usually ventrally and retrolaterally, sometimes also dorsally). Femur-patella joints shifted towards prolateral side. Tibia larger than femur, with two trichobothria. Tibia-tarsus joints shifted towards retrolateral side. Palpal tarsus with large capsulate tarsal organ (Fig. 11H, I; see also Huber 2011: fig. 97), outer diameter 30–35 µm, diameter of opening 15–20 µm; more open (almost exposed) in M. bukidnon sp. nov. (Fig. 11J). Procursus complex, often with distinct dorsal hinged process (e.g., Figs 16C, 43C, 52C), in most species with transparent prolateral membranous flap densely set with teeth (Figs 7A, D, 8B). Genital bulb with distinct proximal sclerite connecting to tarsus, membranous or partly sclerotised embolus, and variably complex set of sclerotised apophyses, sometimes likely homologues of the Pholcus ‘appendix’ and ‘uncus’, sometimes of uncertain homology (Figs 7B, F, 8C, E, F, H).

Figure 7. 

Micropholcus Deeleman-Reinhold & Prinsen; SEM images of male palpal structures A, B M. alfara Huber, sp. nov.; prolateral membranous flap on left procursus and right bulbal processes, prolateral view C, D M. tanomah Huber, sp. nov., tip of left procursus and prolateral membranous flap on left procursus E M. tanomah Huber, sp. nov., left procursus, dorsal view (bold arrow points at tip of procursus) F, G M. tanomah Huber, sp. nov., left bulbal processes, prolateral view, and embolus of same palp in slightly more distal view H M. darbat Huber, sp. nov., left procursus, retrolateral view. Abbreviations: b, genital bulb; e, embolus; hp, dorsal hinged process; mf, membranous prolateral flap; rr, retrolateral ridge; ta, tarsus; tm, transparent membrane. Scale bars: 10 µm (A); 100 µm (B, E, F, H); 20 µm (C, D, G).

Figure 8. 

Micropholcus Deeleman-Reinhold & Prinsen; SEM images of male palpal structures A, B M. darbat Huber, sp. nov.; right bulb and procursus, prolateral view (bold arrow in A points at trochanter apophysis), and prolateral membranous flap of procursus at higher magnification C M. darbat Huber, sp. nov., left bulbal processes D M. ghar Huber, sp. nov., left procursus, retrolateral view E, F M. ghar Huber, sp. nov., right bulbal processes, prolateral and prolateral-ventral views G M. bukidnon Huber, sp. nov., left procursus, prolateral-distal view H M. bukidnon Huber, sp. nov., left bulbal processes, prolateral distal view. Abbreviations: a, putative appendix; b, genital bulb; e, embolus; hp, dorsal hinged process; mf, membranous prolateral flap; pr, procursus; ta, tarsus; u, putative uncus. Scale bars: 100 µm (A, D–H); 10 µm (B); 20 µm (C).

Figure 9. 

Micropholcus Deeleman-Reinhold & Prinsen; SEM images of male palpal trochanter tips and of spinnerets A M. alfara Huber, sp. nov. B M. tanomah Huber, sp. nov. C M. darbat Huber, sp. nov. D M. ghar Huber, sp. nov. E M. bukidnon Huber, sp. nov. F, G M. tanomah Huber, sp. nov., male ALS, and male spinnerets and anal cone (asterisk) H, I M. ghar Huber, sp. nov., male ALS and male spinnerets J M. bukidnon Huber, sp. nov., male ALS. Scale bars: 10 µm (A–F, H, J), 100 µm (G), 20 µm (I).

Legs. Without spines and curved hairs. Without slender metatarsal hairs (cf. Huber et al. 2023a). Without sexually dimorphic short vertical hairs. Chemoreceptive hairs ~ 20–25 µm long, with few side branches (Fig. 12A, H), mostly near leg tips. Retrolateral trichobothrium of tibia 1 at 5–10% of tibia length. Prolateral trichobothrium absent on tibia 1, present on tibiae 2–4. Base of trichobothria evenly rounded, without proximal ridge (cf. Fig. 11D). Legs with roundish cuticular plates (Fig. 12E; diameter ~ 6–8 µm) and rimmed pores (Fig. 12B; outer diameter 2 µm, diameter of opening 0.2 µm) apparently on all leg segments. Tarsus 1 with ~ 20–30 pseudosegments, distally usually fairly distinct. Leg tarsal organs capsulate (Figs 11E–G, 12F; diameter 12–17 µm, diameter of opening 5–7 µm). Tarsus 4 with single row of comb-hairs on prolateral side (Fig. 12G, H; see also Huber 2011: fig. 96). Main tarsal claws with ~ 10 teeth (Fig. 12 C, D).

Figure 10. 

Micropholcus Deeleman-Reinhold & Prinsen; SEM images of male gonopores with epiandrous spigots and of female epigyna A, B M. tanomah Huber, sp. nov. C, D M. darbat Huber, sp. nov. E, F M. ghar Huber, sp. nov. G, H M. bukidnon Huber, sp. nov. Abbreviations: aep, anterior epigynal plate; k, epigynal ‘knob’; pep, posterior epigynal plate. Scale bars: 10 µm (A, G); 100 µm (B, D, F, H); 20 µm (C, E).

Figure 11. 

Micropholcus Deeleman-Reinhold & Prinsen; SEM images of epigynal knobs (A–C), trichobothria (D), and tarsal organs (E–J) A M. tanomah Huber, sp. nov. B M. darbat Huber, sp. nov. C M. ghar Huber, sp. nov. D M. alfara Huber, sp. nov., female left palpal tibia E M. alfara Huber, sp. nov., male right tarsus 2 F M. tanomah Huber, sp. nov., female left tarsus 2 G, H M. darbat Huber, sp. nov., female right tarsus 2 and male palpal tarsus I M. ghar Huber, sp. nov., male palpal tarsus J M. bukidnon Huber, sp. nov., male palpal tarsus. Scale bars: 20 µm (A); 10 µm (B–D, H–J); 2 µm (E–G).

Figure 12. 

Micropholcus Deeleman-Reinhold & Prinsen, SEM images of leg structures A M. tanomah Huber, sp. nov., putative chemoreceptor B M. tanomah Huber, sp. nov., rimmed pore (arrow) on left tarsus 3 C, D M. tanomah Huber, sp. nov., tarsal claws of left legs 1 and 3 E M. ghar Huber, sp. nov., cuticular plate (arrow) and regular mechanoreceptor on right metatarsus 3 F M. ghar Huber, sp. nov., pseudosegmentation (and tarsal organ) of right tarsus 3 G M. ghar Huber, sp. nov., comb-hairs on male tarsus 4 H M. bukidnon Huber, sp. nov., comb-hairs on male tarsus 4. Scale bars: 2 µm (A); 1 µm (B); 20 µm (C); 10 µm (D–H).

Figure 13. 

Known distribution of Micropholcus fauroti (Simon) (A) and of Old World Micropholcus in Mindanao (B), on the Arabian Peninsula (C) and in Morocco (D).

Female. In general, very similar to males (Figs 3, 4). Legs slightly shorter than in males (male / female tibia 1 length: ~ 1.1–1.4, but sample sizes mostly small); tibia 1 length 4.3–9.1. Palpal tarsal organ smaller than in males (outer diameter: 18–25 µm, diameter of opening: 6–10 µm). Palpal tarsus ending distally in pointed tip and pair of strong dorsal hairs (Fig. 5G, H). Spinnerets, leg hairs, cuticular plates, rimmed pores, comb-hairs, leg tarsal organs, and tarsal claws as in male. Epigynum anterior plate usually weakly sclerotised, with rounded process (‘knob’; Fig. 11A–C) in varying position; posterior epigynal plate short and indistinct. Internal genitalia often complex, highly variable, with distinct pair of pore plates.

The type species Micropholcus fauroti has attained a circumtropical distribution, with most records from between 25°S and 30°N (Fig. 5A).

Micropholcus is one of only two Pholcidae genera (together with Pholcus) with autochthonous species in both the Old and New Worlds. New World species are mostly known from the Greater Antilles and from semi-arid regions in Brazil; the genus seems to be largely absent from the humid regions of the Amazon basin. Old World species are currently known from the Arabian Peninsula, Morocco, and the Philippines (Fig. 5B–D). Specimens have been collected from sea level to 2370 m. In Saudi Arabia, all new species described herein were collected above 1200 m. Several of the localities visited below 1000 m had suitable habitats but no Micropholcus.

Old World Micropholcus seem to be very homogeneous with respect to their preferred microhabitats. Most species have been collected from rocks: in caves and at cave entrances, in small caverns of rock walls, and on the undersides of large boulders (Fig. 14). They share this type of microhabitat with most South American species, and with the majority of species of the putative sister genus (Cantikus), suggesting that this might be the plesiomorphic microhabitat. The unusual microhabitat reported for M. jacominae (dry plant debris in an irrigated banana plantation) needs confirmation. The synanthropic M. fauroti is usually found in the upper corners and edges of rooms. Caribbean species have shifted to the undersides of leaves, probably explaining their significantly different general body shape and colour (see Huber and Wunderlich 2006; Huber et al. 2014).

Figure 14. 

Typical habitats of Micropholcus Deeleman-Reinhold & Prinsen in the Old World A Saudi Arabia, ‘Asir, SE of Harajah (type locality of M. harajah Huber, sp. nov.) B Saudi Arabia, ‘Asir, S of Al Fara (type locality of M. alfara Huber, sp. nov.) C Saudi Arabia, ‘Asir, N of Abha (type locality of M. abha Huber, sp. nov.) D Saudi Arabia, Mecca, NW of Maysaan (type locality of M. maysaan Huber, sp. nov.) E Oman, Dhofar, near Shaat sinkhole (type locality of M. shaat Huber, sp. nov.) F Morocco, Fès-Meknès, Kef El Ghar (type locality of M. ghar Huber, sp. nov.) G Morocco, Béni Mellal-Khénifra, Imi n’Ifri (M. khenifra Huber, Lecigne & Lips, sp. nov.) H Philippines, Mindanao, Kabyaw Cave (M. bukidnon Huber, sp. nov.). Photos BAH.

Old World and Brazilian Micropholcus spiders build fine dome-shaped webs but during the day, most species (except those deeper in caves, e.g., M. ghar sp. nov.) sit flat on the rock surface (Fig. 15). The webs of leaf-dwelling Caribbean species have not yet been described. Upon disturbance, the spiders show a range of reactions, from refusing to move, bouncing, walking or running away, to dropping out of the web. Egg sacs are round (in Caribbean species elongated), covered by a barely visible sparse layer of silk (Figs 3, 4), and contain up to ~ 35 eggs; egg diameters range from 0.54 to 0.71 mm. For more detailed observations on Brazilian species, see Huber et al. (2014). For detailed life history data of M. fauroti under lab conditions see Ahmad and Abou-Setta (2017). For anecdotal observations on further Old World species, see individual species descriptions below.

Figure 15. 

Section of cave ceiling (16 × 11 cm), showing nine adult specimens of M. tanomah Huber, sp. nov.; from NW of Tanomah, ‘Asir, Saudi Arabia.

The molecular analysis of Eberle et al. (2018) placed Micropholcus as sister to the South-East Asian genus Cantikus Huber, 2018, within a clade that included three further Old World genera: Leptopholcus Simon, 1893; Pehrforsskalia Deeleman-Reinhold & van Harten, 2001; and Micromerys Bradley, 1877. That analysis included ten species of Micropholcus: the type species M. fauroti, two further Old World species (M. agadir and M. bukidnon sp. nov.) and seven New World species. The monophyly of the genus received maximum support. New World species were nested within a paraphyletic Old World group.

Our NJ tree (Fig. 1) is not expected to reliably reflect phylogenetic relationships. However, some clades that receive reasonable to high support are either congruent with the results of Eberle et al. (2018) (Caribbean clade) or include geographically neighbouring species: the Moroccan clade, the southern Saudi Arabian clade, and the northern Saudi Arabian clade. The latter two are also supported by several morphological similarities each, but it is not clear which of these are synapomorphies and which not. Thus, relationships within Micropholcus are largely unresolved and Fig. 1 should not be misinterpreted in a phylogenetic context.

The genus now includes 30 described species: the Dominican amber fossil M. kiskeya (Huber & Wunderlich, 2006) and 29 extant species. Of the latter, seven occur in South America, six on the Caribbean islands, and 16 in the Old World. All Old World species are treated below except for M. tegulifer Barrientos, 2019 (a loan request was denied by the curator of arthropods, Museu de Ciències Naturals de Barcelona). Numerous undescribed New World species are available in collections, in particular from Brazil (L.S. Carvalho, pers. comm. 2 July 2020). At least one further undescribed species is known to occur in Morocco, represented by a single male specimen deposited in the Muséum d’histoire naturelle, Genève, Switzerland (“sp. Gen377” in Fig. 13D). It resembles M. tegulifer but has a very different uncus. It originates from the Gorges du Dades area in the Drâa-Tafilalet Region, ~ 31.535°N, 5.918°W. Our molecular data indicate that the “Pholcus sp.” CO1 barcode published in Dimitrov et al. (2008) is also from a Micropholcus, different from M. agadir, M. ghar sp. nov., and M. khenifra sp. nov. (Figs 1, 2). It could be M. tegulifer, M. sp. Gen377, or a different new species. Its geographic origin cannot be reconstructed, and the only available (juvenile) specimen is lost (D. Dimitrov and C. Ribera, pers. comm. 20 Mar. and 19 Apr. 2024).

For synonymy, type information, and redescription, see Huber (2011). Numerous further records and an updated distribution map were published in Huber et al. (2017). Since then, new records have been published for Egypt (Ahmad and Abou-Setta 2017), Sri Lanka (Huber 2019), Venezuela (Huber and Villarreal 2020) and India (Vishnudas and Sudhikumar (2021). The map in Fig. 13A summarises all the previous records plus the new records below.

Figure 16. 

Micropholcus fauroti (Simon, 1887); male from Mexico, Nuevo León, Santiago (ZFMK Ar 24655). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Abbreviations: b, genital bulb; c, coxa; f, femur; hp, dorsal hinged process; pa, patella; pr, procursus; ta, tarsus; ti, tibia; tr, trochanter. Scale bar: 0.3 mm.

Colombia: La Guajira • 3 ♂♂, 5 ♀♀; Palomino; 11.2451°N, 73.5619°W; 10 m a.s.l.; in building; 17 Sep. 2022; B.A. Huber leg.; ZFMK Ar 24653.

Mexico: Guerrero • 1 ♂, 3 ♀♀; Coyuca de Benitez; 17.0075°N, 100.0893°W; 20 m a.s.l.; in building; 3 Oct. 2019; B.A. Huber leg.; ZFMK Ar 24654. Nuevo León • 1 ♂, 8 ♀♀, 1 juv.; Santiago; 25.4237°N, 100.1463°W; 450 m a.s.l.; in building; 14 Oct. 2019; B.A. Huber leg.; ZFMK Ar 24655 • 5 ♂♂, 5 ♀♀, in pure ethanol (one male palp and two female abdomens transferred to ZFMK Ar 24655); same collection data as for preceding; ZFMK Mex286.

United Arab Emirates: Dubai • 2 ♂♂, 1 ♀ (“Micropholcus cf. fauroti” in Feulner and Roobas 2016); Dubai, near Emirates Towers; 25.219°N, 55.282°E; 5 m a.s.l.; 3 Jun. 2015; G.R. Feulner leg.; ZFMK Ar 24680.

Oman: Ash Sharqiyah South • 3 ♂♂, 5 ♀♀, 2 juvs; Wadi Tiwi; 22.801°N, 59.240°E; on banana leaves; 60 m a.s.l.; 22 Mar. 2017; B.A. Huber leg.; ZFMK Ar 24656 • 1 ♂, 2 juvs, in pure ethanol; same collection data as for preceding; ZFMK Om27.

Males are easily distinguished from known congeners by long and slender dorsal hinged process on procursus (Fig. 17C; similar but relatively shorter in some Saudi Arabian species, cf. Figs 24C, 40C, etc.); also by unique prolateral process on procursus (arrowed in Fig. 17A) and by unique shapes of processes of genital bulb (Fig. 17D, E). Females are distinguished by distinct U-shaped internal structure visible through epigynal plate in uncleared specimens (Fig. 18A); similar dark internal structures occur in some Saudi Arabian species (e.g., Figs 26A, 30A); also by very large pore plates and large anterior membranous element of internal genitalia (Fig. 18D).

Figure 17. 

Micropholcus fauroti (Simon, 1887); male from Mexico, Nuevo León, Santiago (ZFMK Ar 24655) A–C left procursus in prolateral, dorsal, and retrolateral views; arrow in A points at distinctive prolateral process D, E left genital bulb in prolateral and retrolateral views; bold arrows in D point at distinctive processes of unclear homology. Abbreviations: e, embolus; hp, dorsal hinged process; ps, proximal bulbal sclerite. Scale bars: 0.3 mm.

Figure 18. 

Micropholcus fauroti (Simon, 1887); female from Mexico, Nuevo León, Santiago (ZFMK Ar 24655) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Abbreviations: k, epigynal ‘knob’; pp, pore plate. Scale bars: 0.5 mm (A, B); 0.2 mm (C, D).

Yemen – Al Mahwit • 1 ♂, 1 ♀, paratypes; Khamis Bani Sa’d; 15.185°N, 43.510°E (see Note below); 490 m a.s.l.; 11 Oct. 1999; A. van Harten leg.; RMNH ARA 15019.

The coordinates in Deeleman-Reinhold and van Harten (2001) (15°11'N, 43°25'E) mark a spot 10 km W of Khamis Bani Sa’d, at ~ 440 m a.s.l. (rather than 550 m as reported in the original description). We suspect that our coordinates above are closer to the actual collecting site that could only be reconstructed as being “close to Khamis Bani Sa’d, but not in the village” (A. van Harten, pers. comm. 22 Apr. 2021, 13 Mar. 2024).

Easily distinguished from known congeners by numerous details of male palp: long ventral apophysis on trochanter (Fig. 19C; similar in some Saudi Arabian species, cf. Figs 27C, 31C); distinct dorsal process on femur (arrowed in Fig. 19C; similar only in M. abha sp. nov., cf. Fig. 35C); dorsal-distal hinged process on procursus short and directed towards prolateral (Fig. 20A–C); unique processes of genital bulb (Fig. 20E, F), and by female epigynum and internal genitalia (Figs 21C, 22): extensible knob in posterior position; pair of strongly curved lateral internal sclerites; long pore plates widening and only slightly converging anteriorly.

Figure 19. 

Micropholcus jacominae Deeleman-Reinhold & van Harten, 2001; male paratype from Yemen, Al Mahwit, Khamis Bani Sa’d (RMNH). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views; arrow in C points at distinctive dorsal process on femur. Scale bar: 0.3 mm.

Figure 20. 

Micropholcus jacominae Deeleman-Reinhold & van Harten, 2001; male paratype from Yemen, Al Mahwit, Khamis Bani Sa’d (RMNH) A–C left procursus in prolateral, dorsal, and retrolateral views D tip of left trochanter apophysis E, F left genital bulb in prolateral and retrolateral views; bold arrows in E point at distinctive processes of unclear homology. Abbreviations: e, embolus; hp, dorsal hinged process; mf, membranous prolateral flap; ps, proximal bulbal sclerite; rr, retrolateral ridge; Scale bars: 0.3 mm (A–C, E, F); 0.05 mm (D).

Figure 21. 

Micropholcus jacominae Deeleman-Reinhold & van Harten, 2001; paratypes from Yemen, Al Mahwit, Khamis Bani Sa’d (RMNH) A, B male chelicerae, frontal and lateral views C cleared female genitalia, dorsal view. Abbreviations: k, epigynal ‘knob’; pp, pore plates. Scale bars: 0.3 mm.

Figure 22. 

Micropholcus jacominae Deeleman-Reinhold & van Harten, 2001; female paratype from Yemen, Al Mahwit, Khamis Bani Sa’d (RMNH) A epigynum, ventral view B, C cleared female genitalia, ventral and dorsal views. Scale bars: 0.3 mm.

Male. Measurements. Total body length 2.3, carapace width 0.85. Distance PME-PME 200 µm; diameter PME 65 µm; distance PME-ALE 20 µm; distance AME-AME 25 µm; diameter AME 45 µm. Leg 1: 23.3 (5.9 + 0.4 + 5.7 + 10.2 + 1.1), tibia 2: 3.5, tibia 3: 2.1, tibia 4: 2.9; tibia 1 L/d: 76; diameters of leg femora (at half length) 0.08–0.09; of leg tibiae 0.07–0.08.

Colour (in ethanol). Prosoma and legs pale ochre-whitish, carapace with complex brown median mark similar to Saudi Arabian species (cf. Fig. 3); legs with darkened patellae and tibia-metatarsus joints; abdomen pale grey to whitish.

Body. Habitus similar to Saudi Arabian species (cf. Fig. 3). Ocular area raised (distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.50/0.40), unmodified. Abdomen oval, almost twice as long as wide.

Chelicerae. As in Fig. 21A, B; with pair of relatively long distal apophyses near laminae, each with two modified (cone-shaped) hairs; pair of proximal lateral processes weakly sclerotised and directed towards proximal; and pair of small but distinct proximal frontal processes.

Palps. As in Fig. 19; coxa unmodified; trochanter with long ventral apophysis with very indistinct retrolateral hump proximally and modified hair at tip (Fig. 20D); femur with weakly sclerotised but distinct processes retrolateral-dorsally and prolateral-ventrally; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 20A–C) proximally with sclerotised prolateral hump; at half length with prolateral sclerotised ridge transforming distally into transparent membrane, and brush of dorsal hairs; distally with retrolateral ridge, membranous ventral-prolateral flap, pointed prolateral process, and distinctive dorsal hinged process. Genital bulb (Fig. 20E, F) with strong proximal sclerite; two sclerites of unclear homology, with two pointed processes each; and mostly semi-transparent short embolus, proximally sclerotised, distally membranous with pointed transparent extension.

Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs (many hairs missing); retrolateral trichobothrium of tibia 1 at 8%; prolateral trichobothrium absent on tibia 1; tarsus 1 with > 20 pseudosegments, distally distinct.

Female. In general very similar to male but ocular area slightly less raised and triads closer together (PME-PME 170 µm), carapace pattern more fragmented than in male. Tibia 1: 4.4. Epigynum (Fig. 22A) anterior plate oval, protruding, with membranous, possibly expandable knob in posterior position, tip directed towards posterior; lateral internal sclerites clearly visible in untreated specimens; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 21C, 22B, C) with pair of long pore plates converging and widening anteriorly, pair of lateral sclerites, and transversal ventral sclerotised band; with sclerotised anterior arc continued to posterior margin.

Known from type locality only, in western Yemen (Fig. 13C).

Deeleman-Reinhold and van Harten (2001) report that the spiders were shaken from dry plant debris in an irrigated banana plantation. This microhabitat is unusual for Micropholcus on the Arabian Peninsula and needs confirmation.

Holotype. Saudi Arabia – ‘Asir • ♂; W of Dhahran Al Janub, ‘site 2'; 17.7010°N, 43.3891°E; 2000 m a.s.l.; 24 Mar. 2024; B.A. Huber leg.; KSMA. Paratypes. Saudi Arabia – ‘Asir • 2 ♂♂, 1 ♀, and 1 cleared ♀ abdomen; same collection data as for holotype; ZFMK Ar 24657.

Saudi Arabia – ‘Asir • 1 ♀ (abdomen cleared and transferred to ZFMK Ar 24657), in pure ethanol; same collection data as for holotype; ZFMK SA121.

Distinguished from known congeners by unique shapes of bulbal processes (Fig. 24D, E; similar only in M. abha sp. nov. but without strong retrolateral spine; without distinctive pointed prolateral sclerite as in geographically closest species, M. harajah sp. nov. and M. alfara sp. nov.); from most congeners (except M. harajah sp. nov. and M. alfara sp. nov.) by rectangular dorsal hinged process of procursus with obtuse tip and ventral terminal pointed process and small proximal spine (in other Saudi Arabian species procursus wider and more curved dorsally, without proximal spine; in M. fauroti relatively longer and without spine); most congeners (except for three species above and M. jacominae and M. darbat sp. nov.) also by long trochanter apophysis (Fig. 23C; longer than palpal femur). Female with pair of distinct internal crescent-shaped structures (arrows in Fig. 25C), similar only in M. harajah sp. nov. and M. alfara sp. nov., but without external pockets as in M. harajah sp. nov., crescent-shaped structures farther apart than in M. alfara sp. nov., and anterior arc wider and with different curvature than in M. harajah sp. nov. and M. alfara sp. nov.

Figure 23. 

Micropholcus dhahran Huber, sp. nov.; male from Saudi Arabia, ‘Asir, W of Dhahran Al Janub (ZFMK Ar 24657). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 24. 

Micropholcus dhahran Huber, sp. nov.; male from Saudi Arabia, ‘Asir, W of Dhahran Al Janub (ZFMK Ar 24657) A–C left procursus in prolateral, dorsal, and retrolateral views; bold arrow in C points at proximal spine on hinged process D, E left genital bulb in prolateral and retrolateral views; bold arrows in D point at distinctive processes of unclear homology. Abbreviations: e, embolus; hp, dorsal hinged process; mf, membranous prolateral flap; ps, proximal bulbal sclerite; rr, retrolateral ridge; tm, transparent membrane; Scale bars: 0.3 mm.

Figure 25. 

Micropholcus dhahran Huber, sp. nov.; from Saudi Arabia, ‘Asir, W of Dhahran Al Janub (ZFMK Ar 24657) A, B male chelicerae, frontal and lateral views C cleared female genitalia, dorsal view; bold arrows point at crescent-shaped structures. Abbreviation: pp, pore plate. Scale bars: 0.3 mm.

Male (holotype). Measurements. Total body length 2.5, carapace width 0.8. Distance PME-PME 180 µm; diameter PME 85 µm; distance PME-ALE 20 µm; distance AME-AME 20 µm; diameter AME 55 µm. Leg 1: 27.1 (6.9 + 0.4 + 6.7 + 12.0 + 1.1), tibia 2: 4.0, tibia 3: 2.1, tibia 4: 3.1; tibia 1 L/d: 84; diameters of leg femora (at half length) 0.09–0.10; of leg tibiae 0.08.

Colour (in ethanol). Carapace pale ochre-yellow with distinct brown mark, ocular area and clypeus without darker pattern; sternum monochromous whitish; legs ochre-yellow, patellae brown, tibia-metatarsus joints with indistinct brown ring, femur 1 proximally barely darkened; abdomen pale ochre-grey, dorsally and laterally with whitish internal marks.

Body. Habitus as in Fig. 3A. Ocular area slightly raised. Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.62/0.50), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 25A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs; with pair of low proximal frontal humps; with proximal lateral processes in relatively distal position and directed towards distal.

Palps. As in Fig. 23; coxa unmodified; trochanter with long ventral apophysis with distinct proximal retrolateral hump and modified hair on distal tip; femur distally widened, with distinct ventral hump; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 24A–C) 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 and strong ventral apophysis, large bifid membranous ventral-prolateral flap, and distinctive dorsal hinged process. Genital bulb (Fig. 24D, E) with strong proximal sclerite; with two sclerotised processes of unclear homology: prolateral process with dorsal row of teeth with short hair-like processes, retrolateral process originating from basis of embolus, S-shaped and distally slightly spiralling; and mostly semi-transparent short embolus with distinct pointed extension.

Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs; retrolateral trichobothrium of tibia 1 at 7%; prolateral trichobothrium absent on tibia 1; tarsus 1 with > 20 pseudosegments, only distally distinct.

Variation (male). Tibia 1 in two other males: 6.5, 6.7.

Female. In general very similar to male. Tibia 1 in one female: 4.3 (missing in second female). Epigynum (Fig. 26A, B) barely protruding, anterior plate oval, with indistinct knob-shaped process posteriorly; with pair of lateral and median internal dark structures visible through cuticle; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 25C, 26C, D) with pair of elongated pore plates in transversal position; with pair of lateral sclerites, median crescent-shaped structures, and large membranous anterior arc.

Figure 26. 

Micropholcus dhahran Huber, sp. nov.; female from Saudi Arabia, ‘Asir, W of Dhahran Al Janub (ZFMK Ar 24657) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.3 mm.

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

Known from type locality only, in Saudi Arabia, ‘Asir Province (Fig. 13C).

The spiders were found sitting on the undersides of large boulders, in small cave-like spaces between ground and boulder.

Holotype. Saudi Arabia – ‘Asir • ♂; SE of Al Harajah, ‘site 1’; 17.8681°N, 43.3943°E; 2370 m a.s.l.; 22 Mar. 2024; B.A. Huber leg.; KSMA. Paratypes. Saudi Arabia – ‘Asir • 2 ♂♂, 7 ♀♀; same collection data as for holotype; ZFMK Ar 24658 and 24659.

Saudi Arabia – ‘Asir • 3 ♀♀, in pure ethanol; same collection data as for holotype; ZFMK SA114.

Distinguished from known congeners by unique shapes of bulbal processes, in particular distinctive prolateral sclerite (arrowed in Fig. 28D; similar only in M. alfara sp. nov.) and by unique subdistal conical projection on hinged process of procursus (arrowed in Fig. 28C); from most congeners (except M. alfara sp. nov. and M. dhahran sp. nov.) also by rectangular hinged process of procursus with obtuse tip and small ventral terminal pointed process and small proximal spine (in other Saudi Arabian species procursus wider and more curved dorsally, without proximal spine; in M. fauroti relatively longer and without spine); from most congeners (except for three species above and M. jacominae and M. darbat sp. nov.) also by long trochanter apophysis (Fig. 27C; longer than palpal femur). Female with unique pair of external epigynal pockets (arrowed in Fig. 30A); with distinct internal crescent shaped structures (Fig. 29C; similar only in M. dhahran sp. nov. and M. alfara sp. nov.), crescent-shaped structures farther apart than in M. alfara sp. nov., and anterior arc narrower and with different curvature than in M. dhahran sp. nov.

Figure 27. 

Micropholcus harajah Huber, sp. nov.; male from Saudi Arabia, ‘Asir, SE of Harajah (ZFMK Ar 24658). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 28. 

Micropholcus harajah Huber, sp. nov.; male from Saudi Arabia, ‘Asir, SE of Harajah (ZFMK Ar 24658) A–C left procursus in prolateral, dorsal, and retrolateral views; bold arrowed in C points at distinctive subdistal projection on hinged process D, E left genital bulb in prolateral and retrolateral views; bold arrowed in D points at distinctive cone on prolateral bulbal process. Abbreviations: e, embolus; ps, proximal bulbal sclerite. Scale bars: 0.3 mm.

Figure 29. 

Micropholcus harajah Huber, sp. nov.; from Saudi Arabia, ‘Asir, SE of Harajah A, B male chelicerae, frontal and lateral views (ZFMK Ar 24658) C cleared female genitalia, dorsal view (ZFMK Ar 24659). Scale bars: 0.3 mm.

Figure 30. 

Micropholcus harajah Huber, sp. nov.; female from Saudi Arabia, ‘Asir, SE of Harajah (ZFMK Ar 24659) A, B abdomen, ventral and lateral views; arrows in A point at unique epigynal pockets C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.3 mm.

Male (holotype). Measurements. Total body length 2.7, carapace width 0.9. Distance PME-PME 200 µm; diameter PME 80 µm; distance PME-ALE 20 µm; distance AME-AME 25 µm; diameter AME 55 µm. Leg 1: 26.2 (6.5 + 0.5 + 6.4 + 11.6 + 1.2), tibia 2: 4.0, tibia 3: 2.3, tibia 4: 3.3; tibia 1 L/d: 75; diameters of leg femora (at half length) 0.10–0.11; of leg tibiae 0.085.

Colour (in ethanol). Carapace pale ochre-yellow with large brown median mark connected posteriorly to series of small lateral marks, ocular area slightly darkened, clypeus without darker pattern; sternum mostly whitish, posteriorly slightly darkened; legs ochre-yellow, patellae brown, tibia-metatarsus joints with indistinct brown ring, femur 1 proximally slightly darkened; abdomen pale ochre-grey, dorsally and laterally with larger whitish internal marks.

Body. Habitus as in M. dhahran sp. nov. (cf. Fig. 3A). Ocular area slightly raised (more distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.66/0.50), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 29A, 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. 27; coxa unmodified; trochanter with very long ventral apophysis with small proximal retrolateral hump and modified hair on distal tip; femur small relative to tibia, distally widened, with distinct ventral hump; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 28A–C) proximally with sclerotised prolateral hump; at half-length with prolateral-ventral sclerotised ridge, prolateral thick sclerotised ridge, 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. 28D, E) with strong proximal sclerite; two sclerotised processes of unclear homology: prolateral process with distinctive strong pointed cone directed towards bulbous part of genital bulb; retrolateral process originating from basis of embolus, heavily sclerotised with retrolateral row of four variably strong pointed processes; and mostly semi-transparent short embolus with distinct pointed process and subdistal row of transparent hair-like processes prolaterally.

Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs; retrolateral trichobothrium of tibia 1 not seen in holotype, in paratype at 7%; prolateral trichobothrium absent on tibia 1; tarsus 1 with > 25 pseudosegments, distally distinct.

Variation (male). Tibia 1 in other male: 5.9; missing in third male.

Female. In general very similar to male. Tibia 1 in ten females: 4.3–5.9 (mean 4.9). Epigynum (Fig. 30A, B) variably protruding, anterior plate oval, with indistinct knob-shaped process posteriorly; with pair of lateral sclerites, each provided at posterior end with small pocket, and median internal dark structure visible through cuticle; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 29C, 30C, D) with pair of elongated pore plates in transversal position; with pair of lateral sclerites, median crescent-shaped structures, and large membranous anterior arc.

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

Known from type locality only, in Saudi Arabia, ‘Asir Province (Fig. 13C).

The spiders were found sitting on the undersides of large boulders (Fig. 14A), in small cave-like spaces between boulders and between the ground and boulder. Two egg sacs contained ~ 30–35 eggs each, with an egg diameter of 0.58–0.60 mm.

Holotype. Saudi Arabia – ‘Asir • ♂; S of Al Fara; 18.0487°N, 42.7096°E; 2250 m a.s.l.; 21 Mar. 2024; B.A. Huber leg.; KSMA. Paratypes. Saudi Arabia – ‘Asir • 4 ♂♂, 5 ♀♀ (1 ♂, 1 ♀ used for SEM); same collection data as for holotype; ZFMK Ar 24660 to 24661.

Saudi Arabia – ‘Asir • 1 ♂, 1 ♀, in pure ethanol; same collection data as for holotype; ZFMK SA112.

Distinguished from known congeners by unique shapes of bulbal processes, in particular distinctive prolateral sclerite (arrowed in Fig. 32D; similar only in M. harajah sp. nov., cf. Fig. 28D); from most congeners (except M. harajah sp. nov. and M. dhahran sp. nov.) also by rectangular hinged process of procursus with obtuse tip and small ventral terminal pointed process and small proximal spine (in other Saudi Arabian species procursus wider and more curved dorsally, without proximal spine; in M. fauroti relatively longer and without spine); from most congeners (except for three species above and M. jacominae and M. darbat sp. nov.) also by long trochanter apophysis (Fig. 31C; longer than palpal femur). Female with distinct internal crescent-shaped structures (Fig. 33C), similar only in M. dhahran sp. nov. and M. harajah sp. nov., but closer together; anterior arc narrow (Fig. 33C), similar only in M. harajah sp. nov. (cf. Fig. 29C), in M. dhahran sp. nov. wider and with different curvature. From M. harajah sp. nov. also distinguished by absence of subdistal conical projection on hinged process of procursus (cf. Fig. 28C) and by absence of pair of external epigynal pockets (cf. Fig. 30A).

Figure 31. 

Micropholcus alfara Huber, sp. nov.; male from Saudi Arabia, ‘Asir, S of Al Fara (ZFMK Ar 24660). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 32. 

Micropholcus alfara Huber, sp. nov.; male from Saudi Arabia, ‘Asir, S of Al Fara (ZFMK Ar 24660) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views; arrow in D points at distinctive cone on prolateral bulbal process. Scale bars: 0.3 mm.

Figure 33. 

Micropholcus alfara Huber, sp. nov.; from Saudi Arabia, ‘Asir, S of Al Fara A, B male chelicerae, frontal and lateral views (ZFMK Ar 24660) C cleared female genitalia, dorsal view (ZFMK Ar 24661). Scale bars: 0.3 mm.

Male (holotype). Measurements. Total body length 2.6, carapace width 1.0. Distance PME-PME 185 µm; diameter PME 80 µm; distance PME-ALE 25 µm; distance AME-AME 20 µm; diameter AME 55 µm. Leg 1: 28.4 (7.1 + 0.4 + 6.9 + 12.8 + 1.2), tibia 2: 4.1, tibia 3: 2.3, tibia 4: 3.3; tibia 1 L/d: 81; diameters of leg femora (at half length) 0.09–0.10; of leg tibiae 0.085.

Colour (in ethanol). Carapace pale ochre-yellow with large brown median mark connected posteriorly to series of small lateral marks, ocular area slightly darkened, clypeus without darker pattern; sternum whitish; legs ochre-yellow, patellae brown, tibia-metatarsus joints with indistinct brown ring, femur 1 proximally slightly darkened (very indistinct); abdomen ochre-grey, dorsally and laterally with large whitish internal marks.

Body. Habitus as in Fig. 3C. Ocular area slightly raised (more distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.64/0.48), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 33A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs (Fig. 6A, B); with pair of proximal frontal processes; with prominent pair of proximal lateral processes.

Palps. As in Fig. 31; coxa unmodified; trochanter with very long ventral apophysis with small proximal retrolateral hump and modified hair on distal tip (Fig. 9A); femur small relative to tibia, distally widened, with distinct ventral hump; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 32A–C) proximally with sclerotised prolateral hump; at half-length with prolateral-ventral sclerotised ridge, prolateral thick sclerotised ridge, and brush of dorsal hairs; distally with small retrolateral ridge and strong ventral apophysis, membranous ventral-prolateral flap (Fig. 7A), and dorsal hinged process. Genital bulb (Figs 7B, 32D, 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; retrolateral process originating from basis of embolus, heavily sclerotised with retrolateral row of pointed cones of similar sizes; and mostly semi-transparent short embolus with membranous pointed extension and subdistal row of transparent hair-like processes prolaterally.

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: 6.8–7.2 (mean 7.0).

Female. In general very similar to male. Tibia 1 in five females: 4.6–5.4 (mean 5.0). Epigynum (Fig. 34A, B) variably protruding, anterior plate oval, with small and indistinct knob-shaped process posteriorly; with pair of lateral sclerites bent towards lateral anteriorly, without small pockets at posterior ends; and median internal dark structure visible through cuticle. Posterior epigynal plate very short and indistinct. Internal genitalia (Figs 33C, 34C, D) with pair of elongated pore plates in transversal position; with pair of lateral sclerites, median crescent-shaped structures, and large membranous anterior arc.

Figure 34. 

Micropholcus alfara Huber, sp. nov.; female from Saudi Arabia, ‘Asir, S of Al Fara (ZFMK Ar 24661) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.3 mm.

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

Known from type locality only, in Saudi Arabia, ‘Asir Province (Fig. 13C).

The spiders were found sitting on the undersides of large boulders (Fig. 14B), in small cave-like spaces between ground and boulder. Two egg sacs had diameters of 2.0–2.2 mm, and contained ~ 25–35 eggs each, with an egg diameter of 0.58–0.62 mm.

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.

Saudi Arabia – ‘Asir • 1 ♂, 3 ♀♀ (one abdomen transferred to ZFMK Ar 24662), in pure ethanol; same collection data as for holotype; ZFMK SA111.

Distinguished from known congeners by presence of dorsal process on palpal femur (arrowed in Fig. 35C; similar only in M. jacominae), by bipartite tip of dorsal hinged process of procursus (arrowed in Fig. 36C), and by unique shapes of bulbal processes (Fig. 36D, 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. 35C; longer than palpal femur). Female with unique lateral sacs in internal genitalia (arrows in Fig. 37C); 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. 28C) and by absence of pair of external epigynal pockets (cf. Fig. 30A).

Figure 35. 

Micropholcus abha Huber, sp. nov.; male from Saudi Arabia, ‘Asir, N of Abha (ZFMK Ar 24662). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views; arrow in C points at distinctive dorsal process on femur. Scale bar: 0.3 mm.

Figure 36. 

Micropholcus abha Huber, sp. nov.; male from Saudi Arabia, ‘Asir, N of Abha (ZFMK Ar 24662) A–C left procursus in prolateral, dorsal, and retrolateral views; arrow in C pointsat distinctive bipartite tip of hinged process D, E left genital bulb in prolateral and retrolateral views; arrow in E points at distinctive retrolateral pointed process. Scale bars: 0.3 mm.

Figure 37. 

Micropholcus abha Huber, sp. nov.; from Saudi Arabia, ‘Asir, N of Abha (ZFMK Ar 24662) A, B male chelicerae, frontal and lateral views C cleared female genitalia, dorsal view; arrows point at distinctive lateral sacs. Scale bars: 0.3 mm.

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. 3E. 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. 37A, 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. 36A–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. 36D, 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. 38A, 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 37C, 38C, 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.

Figure 38. 

Micropholcus abha Huber, sp. nov.; female from Saudi Arabia, ‘Asir, N of Abha (ZFMK Ar 24662) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.3 mm.

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

Known from type locality only, in Saudi Arabia, ‘Asir Province (Fig. 13C).

The spiders were found in small caverns at rock outcrops in an open environment (Fig. 14C), i.e., in less sheltered microhabitats than most other species.

Holotype. Saudi Arabia – ‘Asir • ♂; NW of Tanomah; 19.0220°N, 42.1247°E; 2250 m a.s.l.; 19 Mar. 2024; B.A. Huber leg.; KSMA. Paratypes. Saudi Arabia – ‘Asir • 21 ♂♂, 24 ♀♀, 1 juv. (1 ♂, 1 ♀ used for SEM); same collection data as for holotype; ZFMK Ar 24663 to 24664.

Saudi Arabia – ‘Asir • 3 ♀♀, 4 juvs; in pure ethanol; same collection data as for holotype; ZFMK SA100.

Distinguished from similar species in the northern Saudi Arabian group (M. bashayer sp. nov., M. maysaan sp. nov.) by very slender main bulbal process (Fig. 40D; wider in other species), and by epigynal ‘knob’ in posterior rather than central position on epigynal plate (Fig. 42A, B); from M. maysaan sp. nov. also by less widened hinged process of procursus (Fig. 40C); from species of the southern Saudi Arabian group and M. jacominae by shorter male palpal trochanter apophysis (Fig. 39C), internal female genitalia with membranous central element rather than distinct arc (Fig. 41C), and without crescent-shaped structures.

Figure 39. 

Micropholcus tanomah Huber, sp. nov.; male from Saudi Arabia, ‘Asir, NW of Tanomah (ZFMK Ar 24663). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 40. 

Micropholcus tanomah Huber, sp. nov.; male from Saudi Arabia, ‘Asir, NW of Tanomah (ZFMK Ar 24663) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views. Abbreviation: hp, dorsal hinged process. Scale bars: 0.3 mm.

Figure 41. 

Micropholcus tanomah Huber, sp. nov.; male from Saudi Arabia, ‘Asir, NW of Tanomah A, B male chelicerae, frontal and lateral views (ZFMK Ar 24663) C cleared female genitalia, dorsal view (ZFMK Ar 24664); bold arrow points at membranous central element. Abbreviations: k, epigynal ‘knob’; pp, pore plate. Scale bars: 0.3 mm.

Figure 42. 

Micropholcus tanomah Huber, sp. nov.; female from Saudi Arabia, ‘Asir, NW of Tanomah (ZFMK Ar 24664) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.5 mm.

Male (holotype). Measurements. Total body length 3.4, carapace width 1.2. Distance PME-PME 210 µm; diameter PME 80 µm; distance PME-ALE 20 µm; distance AME-AME 20 µm; diameter AME 45 µm. Leg 1: 28.7 (7.0 + 0.5 + 7.1 + 12.7 + 1.4), tibia 2: 4.5, tibia 3: 2.9, tibia 4: 4.0; tibia 1 L/d: 71; diameters of leg femora (at half length) 0.11–0.12; of leg tibiae 0.10.

Colour (in ethanol). Carapace pale ochre-yellow with distinct brown mark, ocular area not darkened, clypeus with very indistinct darker pattern; sternum monochromous whitish; legs ochre-yellow to light brown, patella dark brown, tibia-metatarsus joints with small brown ring, femur 1 ventrally proximally brown (less distinct also femur 2); abdomen pale ochre-grey, with indistinct darker internal marks.

Body. Habitus as in Fig. 3F. Ocular area slightly raised (distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.74/0.58), unmodified. Abdomen oval, approximately twice as long as wide. Gonopore with four epiandrous spigots (Fig. 10A). Spinnerets as in Fig. 9F, G.

Chelicerae. As in Fig. 41A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs (Fig. 6C); with pair of distinct proximal frontal apophyses; with pair of very low and indistinct lateral humps.

Palps. As in Fig. 39; coxa unmodified; trochanter with long ventral apophysis with distinct proximal retrolateral hump and modified hair on distal tip (Fig. 9B); femur distally widened, with subdistal ventral hump; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 40A–C) 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, large bifid membranous ventral-prolateral flap (Fig. 7C, D), and dorsal hinged process. Genital bulb (Fig7F, G, 40D, E) with strong proximal sclerite; with two sclerotised processes of unclear homology: prolateral process long and slender, with small, pointed branch on retrolateral side; retrolateral process simple, originating from basis of embolus and directed parallel to prolateral process; and mostly semi-transparent short embolus with membranous 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 > 20 pseudosegments, distally distinct.

Variation (male). Tibia 1 in 21 other males: 5.1–7.3 (mean 6.5). Carapace pattern very consistent. Abdomen usually with large white marks dorsally and laterally.

Female. In general very similar to male but anterior leg femora proximally not darkened; ocular area with large median and small lateral brown marks. Tibia 1 in 24 females: 4.4–5.9 (mean 5.2). Epigynum (Figs 10B, 42A, B) protruding, anterior plate oval, mostly dark brown except medially posteriorly, with small knob-shaped process (Fig. 11A) near posterior margin; posterior epigynal plate very short and indistinct, light brown. Internal genitalia (Figs 41C, 42C, D) with pair of elongated pore plates in transversal position; with pair of lateral sclerites and complex system of membranous structures.

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

Known from type locality only, in Saudi Arabia, ‘Asir Province (Fig. 13C).

The spiders were found in caverns among and under boulders, often together with a representative of Smeringopus Simon, 1890 (Araneae: Pholcidae). Both species sometimes occurred in very high densities. In one case, a ceiling of a cave was estimated to measure ~ 3 m² and to contain ~ 250 large (adult and penultimate instar) specimens (i.e., with average distances between specimens of ~ 10 cm) (Fig. 15). One egg sac had a diameter of 2.5 mm, and contained ~ 35 eggs. Egg diameters ranged from 0.69 to 0.71 mm.

Holotype. Saudi Arabia – ‘Asir • ♂; NW of Al Bashayer; 19.8194°N, 41.8824°E; 1850 m a.s.l.; 19 Mar. 2024; B.A. Huber leg.; KSMA. Paratypes. Saudi Arabia – ‘Asir • 8 ♂♂, 10 ♀♀; same collection data as for holotype; ZFMK Ar 24665 to 24666.

Saudi Arabia – ‘Asir • 2 ♂♂, 3 ♀♀; in pure ethanol; same collection data as for holotype; ZFMK SA96.

Distinguished from most similar known species (M. maysaan sp. nov.) by less widened dorsal hinged process of procursus (Fig. 44C), by pointed projection of bulbal process (arrowed in Fig. 44E) not directed towards bulbous part, and by darkened central area of epigynal plate (Fig. 46A; rather than anterior part, cf. Fig. 50A). From third species in northern Saudi Arabian group (M. tanomah sp. nov.) by wider main bulbal process (Fig. 44D), by epigynal ‘knob’ in central rather than posterior position on epigynal plate (Fig. 46A). From species of the southern Saudi Arabian group and M. jacominae by shorter male palpal trochanter apophysis (Fig. 43C), internal female genitalia with membranous central element rather than distinct arc (Fig. 45C) and without crescent-shaped structures.

Figure 43. 

Micropholcus bashayer Huber, sp. nov.; male from Saudi Arabia, ‘Asir, NW of Al Bashayer (ZFMK Ar 24665). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 44. 

Micropholcus bashayer Huber, sp. nov.; male from Saudi Arabia, ‘Asir, NW of Al Bashayer (ZFMK Ar 24665) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views; bold arrow in E points at retrolateral process originating from embolus. Abbreviation: e, embolus. Scale bars: 0.3 mm.

Figure 45. 

Micropholcus bashayer Huber, sp. nov.; from Saudi Arabia, ‘Asir, NW of Al Bashayer A, B male chelicerae, frontal and lateral views (ZFMK Ar 24665) C cleared female genitalia, dorsal view (ZFMK Ar 24666). Scale bars: 0.3 mm.

Figure 46. 

Micropholcus bashayer Huber, sp. nov.; female from Saudi Arabia, ‘Asir, NW of Al Bashayer (ZFMK Ar 24666) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.5 mm.

Male (holotype). Measurements. Total body length 3.0, carapace width 1.0. Distance PME-PME 195 µm; diameter PME 80 µm; distance PME-ALE 20 µm; distance AME-AME 20 µm; diameter AME 50 µm. Leg 1: 23.7 (6.0 + 0.5 + 5.9 + 10.1 + 1.2), tibia 2: 3.6, tibia 3: 2.3, tibia 4: 3.4; tibia 1 L/d: 66; diameters of leg femora (at half length) 0.10–0.11; of leg tibiae 0.09.

Colour (in ethanol). Carapace pale ochre-yellow with distinct brown mark, ocular area and clypeus also with indistinct darker pattern; sternum monochromous whitish; legs ochre-yellow to light brown, patella dark brown, tibia-metatarsus joints with small brown ring, femur 1 ventrally proximally brown (less distinct also femur 2); abdomen pale ochre-grey, dorsally and laterally with whitish internal marks.

Body. Habitus as in M. maysaan sp. nov. (cf. Fig. 3H). Ocular area slightly raised. Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.68/0.48), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 45A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs; with pair of distinct proximal frontal apophyses; without proximal lateral processes.

Palps. As in Fig. 43; coxa unmodified; trochanter with long ventral apophysis with distinct proximal retrolateral hump and modified hair on distal tip; femur distally widened, otherwise unmodified; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 44A–C) 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, large bifid membranous ventral-prolateral flap, and distinctive dorsal hinged process. Genital bulb (Fig. 44D, E) with strong proximal sclerite; with two sclerotised processes of unclear homology: prolateral process large but simple, with small, pointed side branch; retrolateral process very simple, originating from basis of embolus and directed parallel to prolateral process; and mostly semi-transparent short embolus with membranous extension.

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 nine males (incl. holotype): 5.5–6.7 (mean 6.0).

Female. In general, very similar to male but anterior leg femora proximally not darkened. Tibia 1 in ten females: 4.4–5.4 (mean 4.9). Epigynum (Fig. 46A, B) protruding, anterior plate oval, with knob-shaped process medially; with large brown mark slightly divided medially, anteriorly light, posteriorly with small median dark line; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 45C, 46C, D) with pair of pore plates in transversal position; with pair of lateral sclerites and complex system of membranous structures.

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

Known from type locality only, in Saudi Arabia, ‘Asir Province (Fig. 13C).

The spiders were found sitting on the undersides of large boulders, in small cave-like spaces between boulder and ground. One egg sac contained approximately 30 eggs, with an egg diameter of 0.60 mm. One female had an acrocerid larva in her book lung (Fig. 76A–D).

Holotype. Saudi Arabia – Mecca • ♂; NW of Maysaan; 20.7717°N, 40.7985°E; 2560 m a.s.l.; 29 Mar. 2024; B.A. Huber leg.; KSMA. Paratypes. Saudi Arabia – Mecca • 4 ♂♂, 5 ♀♀; same collection data as for holotype; ZFMK Ar 24667 to 24668.

Saudi Arabia – Mecca • 2 ♀♀, 4 juvs; in pure ethanol; same collection data as for holotype; ZFMK SA140 – Al Bahah • 2 ♂♂, 6 ♀♀; NW of Al Bahah, ‘site 2’; 20.2095°N, 41.3700°E; 2250 m a.s.l.; 16 Mar. 2024; B.A. Huber leg.; ZFMK Ar 24669 • 1 ♂, 4 ♀♀; in pure ethanol; same collection data as for preceding; ZFMK SA88 • 1 ♂; S of Al Bahah, ‘site 2’; 19.9896°N, 41.4373°E; 1250 m a.s.l.; 17 Mar. 2024; B.A. Huber leg.; ZFMK Ar 24670.

Distinguished from other species in northern Saudi Arabian group (M. bashayer sp. nov., M. tanomah sp. nov.) by strongly widened dorsal hinged process of procursus (Fig. 48C), by pointed process originating from embolus directed towards bulbous part (arrowed in Fig. 48E); from M. bashayer sp. nov. also by darkened anterior area of epigynal plate (Fig. 50A; rather than central area, cf. Fig. 46A); from M. tanomah sp. nov. also by wider main bulbal process (Fig. 48D), and by epigynal ‘knob’ in central rather than posterior position on epigynal plate (Figs 50A, B, 51A, B). From species of the southern Saudi Arabian group and M. jacominae by shorter male palpal trochanter apophysis (Fig. 47C), internal female genitalia with membranous central element rather than distinct arc (Fig. 49C), and without crescent-shaped structures.

Male (holotype). Measurements. Total body length 3.1, carapace width 1.1. Distance PME-PME 200 µm; diameter PME 90 µm; distance PME-ALE 30 µm; distance AME-AME 40 µm; diameter AME 50 µm. Leg 1: 26.3 (6.6 + 0.5 + 6.6 + 11.3 + 1.3), tibia 2: 4.2, tibia 3: 2.7, tibia 4: 3.7; tibia 1 L/d: 69; diameters of leg femora (at half length) 0.10–0.11; of leg tibiae 0.09–0.10.

Colour (in ethanol). Carapace pale ochre-yellow with distinct brown mark, clypeus also with indistinct darker pattern; sternum monochromous whitish; legs ochre-yellow to light brown, patella dark brown, tibia-metatarsus joints with small brown ring, femur 1 ventrally proximally brown (less distinct also femur 2); abdomen pale ochre-grey, dorsally and laterally with whitish internal marks.

Body. Habitus as in Fig. 3H. Ocular area slightly raised. Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.72/0.58), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 49A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs; with pair of distinct proximal frontal apophyses; without proximal lateral processes.

Palps. As in Fig. 47; coxa unmodified; trochanter with long ventral apophysis with distinct proximal retrolateral hump and modified hair on distal tip; femur distally widened, otherwise unmodified; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 48A–C) 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, large bifid membranous ventral-prolateral flap, and distinctively widened dorsal hinged process. Genital bulb (Fig. 48D, E) with strong proximal sclerite; with two sclerotised processes of unclear homology: prolateral process large but simple, with small, pointed side branch; retrolateral process very simple, originating from basis of embolus and pointing towards globular part of bulb; and mostly semi-transparent short embolus with membranous extensions.

Figure 47. 

Micropholcus maysaan Huber, sp. nov.; male from Saudi Arabia, Mecca, NW of Maysaan (ZFMK Ar 24667). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 48. 

Micropholcus maysaan Huber, sp. nov.; male from Saudi Arabia, Mecca, NW of Maysaan (ZFMK Ar 24667) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views; bold arrow in E points at retrolateral process originating from embolus. Abbreviation: e, embolus. Scale bars: 0.3 mm.

Figure 49. 

Micropholcus maysaan Huber, sp. nov.; male from Saudi Arabia, Mecca, NW of Maysaan (ZFMK Ar 24667), female from Saudi Arabia, Al Bahah, NW of Al Bahah (ZFMK Ar 24669) A, B male chelicerae, frontal and lateral views C cleared female genitalia, dorsal view. Scale bars: 0.3 mm.

Figure 50. 

Micropholcus maysaan Huber, sp. nov.; female from Saudi Arabia, Mecca, NW of Maysaan (ZFMK Ar 24668) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars. 0.5 mm.

Figure 51. 

Micropholcus maysaan Huber, sp. nov.; female from Saudi Arabia, Mecca, NW of Al Bahah (ZFMK Ar 24669) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.5 mm.

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 eight males (incl. holotype): 5.1–7.1 (mean 6.1). Males from NW of Maysaan and from NW of Al Bahah appear essentially identical. In the single male from S of Al Bahah, the shape of the dorsal hinged process of the procursus is slightly different: its widest point is at one third of its length rather than at half-length. Also, the retrolateral bulbal process in this specimen is (in prolateral view) less strongly protruding from behind the prolateral process.

Female. In general, very similar to male but anterior leg femora proximally not darkened. Tibia 1 in ten females: 4.6–5.5 (mean 4.9). Epigynum (Fig. 50A, B) protruding, anterior plate oval, with prominent knob-shaped process medially; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 49C, 50C, D, 51C, D) with pair of oval pore plates in transversal position; with pair of lateral sclerites and complex system of membranous structures. Females from NW of Maysaan and from NW of Al Bahah appear essentially identical. No female is available from S of Al Bahah.

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

Known from three localities in Saudi Arabia, in Mecca and Al Bahah Provinces (Fig. 13C).

At the type locality, the spiders were found in small caverns under large boulders on a hill (Fig. 14D), where they were tightly pressed against the rock on the ceiling. Upon disturbance, they were very reluctant to move; only when the sparse sheet of silk covering the spider was removed, they started to run away over the rock. NW of Al Bahah most specimens were collected from a small hole under a flat rock; distances between specimens ranged from ~ 10–20 cm. One egg sac contained ~ 12 eggs, with an egg diameter of 0.62 mm.

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.

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 Om133 • 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 Om147 • 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 Om146 • 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 Om142.

Males are easily distinguished from known congeners by shape of procursus with distinctive dorsal hinged process split into two branches (Fig. 53C); also by shapes of bulbal processes (Fig. 53D, E; prolateral apophysis simple, with small proximal prolateral hump) and cheliceral processes (Fig. 54A, 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. 52C). 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. 55A), pore plates oval and converging anteriorly (Fig. 55C), and internal genitalia without large membranous sac.

Figure 52. 

Micropholcus darbat Huber, sp. nov.; male from Oman, Dhofar, Wadi Darbat (ZFMK Ar 24672). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 53. 

Micropholcus darbat Huber, sp. nov.; male from Oman, Dhofar, Wadi Darbat (ZFMK Ar 24672) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views; bold arrow in D points at proximal hump on prolateral bulbal process. Abbreviations: e, embolus; hp, dorsal hinged process; ps, proximal bulbal sclerite. Scale bars: 0.3 mm.

Figure 54. 

Micropholcus darbat Huber, sp. nov.; from Oman, Dhofar, Wadi Darbat (ZFMK Ar 24672) A, B male chelicerae, frontal and lateral views C cleared female genitalia, dorsal view. Scale bars: 0.3 mm.

Figure 55. 

Micropholcus darbat Huber, sp. nov.; female from Oman, Dhofar, Wadi Darbat (ZFMK Ar 24672) A epigynum, ventral view B, C cleared female genitalia, ventral and dorsal views. Arrows point at distinctive internal pockets. Scale bars: 0.3 mm.

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. 4A. Ocular area raised (distinct in frontal view; Fig. 5B). 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. 10C).

Chelicerae. As in Figs 6D, 54A, B; with pair of distal apophyses near laminae, each with two cone-shaped hairs (Fig. 6E); 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. 9C); 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 7H, 53A–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. 8A, B), and distinctive dorsal hinged process split into two branches. Genital bulb (Figs 8C, 53D, 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 10D, 55A) anterior plate oval, protruding, with membranous knob (Fig. 11B) 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. 54C, 55B, 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.

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

Known from several localities in Dhofar, western Oman (Fig. 13C).

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. 76E, F).

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.

Oman – Dhofar • 4 ♂♂, 2 ♀♀, 1 juv.; same collection data as for holotype; ZFMK Ar 24677 • 1 ♀, 1 juv.; same collection data as for holotype but 24 Feb. 2018; ZFMK Ar 24678 • 3 ♀♀, in pure ethanol; same collection data as for holotype but 24–25 Feb. 2018; ZFMK Om137.

Males are easily distinguished from known congeners by several details of male palp (Figs 56, 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. 58C), by distinctive sclerotised band medially on epigynal plate (Fig. 59A), and by presence of large membranous sac in internal genitalia (Fig. 59D); from geographically close M. darbat sp. nov. also by larger and wider pore plates (Fig. 58C).

Figure 56. 

Micropholcus shaat Huber, sp. nov.; male from Oman, Dhofar, Shaat sinkhole (ZFMK Ar 24677). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views; arrow in C points at distinctive process proximally on trochanter apophysis. Scale bar: 0.3 mm.

Figure 57. 

Micropholcus shaat Huber, sp. nov.; male from Oman, Dhofar, Shaat sinkhole (ZFMK Ar 24677) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views. Abbreviation: hp, dorsal hinged process. Scale bars: 0.3 mm.

Figure 58. 

Micropholcus shaat Huber, sp. nov.; from Oman, Dhofar, Shaat sinkhole (ZFMK Ar 24677) A, B male chelicerae, frontal and lateral views C cleared female genitalia, dorsal view. Abbreviations: k, epigynal ‘knob’; pp, pore plates. Scale bars: 0.3 mm.

Figure 59. 

Micropholcus shaat Huber, sp. nov.; two females from Oman, Dhofar, Shaat sinkhole (ZFMK Ar 24677) A epigynum, ventral view B, C cleared female genitalia, ventral and dorsal views, same specimen as in A; membranous sac removed D, E cleared female genitalia of second female, dorsal views; membranous sac is shown in D (arrows), but was removed for E. Abbreviation: k, epigynal ‘knob’. Scale bars: 0.3 mm.

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. 4C. 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. 58A, B; 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; 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. 57A–C) 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. 57D, E) 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. 59A) 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 58C, 59B–E) with pair of large sclerotised pore plates, with roughly square-shaped sclerotised opening leading into large round membranous sac (collapsed in Fig. 59D; removed in Fig. 59B, C, E); with complex system of lateral membranous structures.

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

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

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

Morocco: Souss-Massa • 3 ♂♂, 2 ♀♀; Paradise Valley; 30.588°N, 9.528°W; 305 m a.s.l.; 13 Sep. 2018; B.A. Huber leg.; ZFMK Ar 24679 • 2 ♂♂, 2 ♀♀ (one abdomen transferred to ZFMK Ar 24679), in pure ethanol; same collection data as for preceding; ZFMK Mor76 • 2 ♀♀, in pure ethanol; Agadir, path to Kasbah Hill; 30.4289°N, 9.6186°W; 60 m a.s.l.; 28 Nov. 2016; S. Huber leg.; ZFMK Sieg27 • 4 ♀♀, in pure ethanol; Agadir, path to Kasbah Hill; 30.4297°N, 9.6189°W; 110 m a.s.l.; 7 Sep. 2014; S. Huber leg.; ZFMK Sieg11 • 1 ♂, in pure ethanol; Road Agadir-Alma; 30.4864°N, 9.5650°W; 440 m a.s.l.; 27 Nov. 2016; S. Huber leg.; ZFMK Sieg25. Marrakech-Safi • 1 ♀; NE of Tizi n’Test; 30.897°N, 8.339°W; 2075 m a.s.l.; 12 Sep. 2018; B.A. Huber leg.; ZFMK Ar 24683.

Distinguished from similar congeners (M. tegulifer, M. ghar sp. nov.) by short and distally widened dorsal hinged process of procursus (Fig. 61C), by rounded uncus with scales (Fig. 61D, E; similar only in M. khenifra sp. nov., cf. Fig. 69E), and by flat and oval appendix with small proximal spine and prolateral ridge (Fig. 61D); from M. tegulifer also by presence of two pairs of processes proximally on male chelicerae (Fig. 62A, B; absent in M. tegulifer), by lateral marks on carapace (Fig. 4D, E; absent in M. tegulifer), and by oval rather than elongate pore plates in female internal genitalia. From M. ghar sp. nov. also distinguished by smaller triangular plate posteriorly on epigynum (compare Fig. 63B with Fig. 67A).

Figure 60. 

Micropholcus agadir (Huber, 2011); male from Morocco, Souss-Massa, Paradise Valley (ZFMK Ar 24679). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 61. 

Micropholcus agadir (Huber, 2011); male from Morocco, Souss-Massa, Paradise Valley (ZFMK Ar 24679) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views. Abbreviations: a, putative appendix; e, embolus; hp, dorsal hinged process; ps, proximal bulbal sclerite; u, putative uncus. Scale bars: 0.3 mm.

Figure 62. 

Micropholcus agadir (Huber, 2011); male from Morocco, Souss-Massa, Paradise Valley (ZFMK Ar 24679), female from Morocco, Souss-Massa, 7 km N Agadir (IRSB) A, B male chelicerae, frontal and lateral views C cleared female genitalia, dorsal view (from Huber 2011). Abbreviation: pp, pore plate. Scale bars: 0.3 mm.

Figure 63. 

Micropholcus agadir (Huber, 2011); female from Morocco, Souss-Massa, Paradise Valley (ZFMK Ar 24679) A, C abdomen, ventral and lateral views B epigynum, ventral view D, E cleared genitalia, ventral and dorsal views. Abbreviations: aep, anterior epigynal plate; k, epigynal ‘knob’; pep, posterior epigynal plate. Scale bars: 0.5 mm (A, C); 0.3 mm (B, D, E).

Description (amendments; see also Huber 2011). Tibia 1 length in seven males (incl. holotype): 6.0–7.4 (mean 6.7); in 12 females (including those in Huber 2011): 4.8–5.9 (mean 5.6). The drawings in Huber (2011) are from the male holotype and from a topotypical female. Compared to the newly collected males, the procursus of the holotype was slightly twisted towards prolateral; thus, the dorsal hinged process was described as “prolateral branch”. The new material also shows that the dorsal process is connected to the main part of the procursus by slightly membranous cuticle, i.e., it is hinged, comparable with the dorsal processes of congeneric species. The female epigynal knob was originally said to be on the posterior plate (Huber 2011). Instead, it is situated on a small, slightly separate triangular part of the anterior plate. The posterior epigynal plate in M. agadir is indistinct (Fig. 63B); it was indicated by a row of hairs in Huber (2011: fig. 1610), but not explicitly drawn.

Known from several localities in southern Morocco, in Souss-Massa and Marrakech-Safi regions (Fig. 13D).

In Paradise Valley, the spiders were found on overhanging rock-surfaces, often in very close proximity to Holocnemus reini (C. Koch, 1873). While the latter had large and distinct webs, the webs of Micropholcus were barely visible. Two egg sacs had diameters of 1.9 and 2.4 mm, respectively, contained 23/31 eggs with an egg diameter of 0.60–0.63 (Huber and Eberle 2021).

Holotype. Morocco – Fès-Meknès • ♂; Kef el Ghar (=Rhar); 34.4788°N, 4.2766°W; 620 m a.s.l.; 22 Sep. 2018; B.A. Huber leg.; ZFMK Ar 24684.

Morocco – Fès-Meknès • 14 ♂♂, 12 ♀♀ (1 ♂, 1 ♀ used for SEM); same collection data as for holotype; ZFMK Ar 24685 to 24686 • 2 ♂♂, 2 ♀♀, 1 juv., in pure ethanol; same collection data as for holotype; ZFMK Mor100 • 1 ♂, 2 ♀♀; same locality as for holotype, 2 Jun. 1978; P. Strinati leg.; MHNG • 1 ♂, 4 ♀♀, 6 juvs; same locality as for holotype, 2 Jun. 1978; B. Hauser leg.; MHNG.

Distinguished from similar congeners (M. agadir, M. tegulifer) by unique shape of uncus (Fig. 65D, E; with sickle-shaped process and series of pointed processes along edge), by unique shape of appendix (Fig. 65D, E; two small pointed processes proximally, larger process distally, and membranous distal area), and by large sclerotised triangular plate on epigynum with whitish median area (Fig. 67A); also by pair of distinctive membranous structures laterally in female internal genitalia (arrows in Fig. 66C); from M. tegulifer also by presence of two pairs of processes proximally on male chelicerae (Fig. 66A, B; absent in M. tegulifer), by lateral marks on carapace (Fig. 4F; absent in M. tegulifer), and by roundish rather than elongate pore plates (Fig. 66C).

Figure 64. 

Micropholcus ghar Huber, sp. nov.; male from Morocco, Fès-Meknès, Kef el Ghar (ZFMK Ar 24685). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 65. 

Micropholcus ghar Huber, sp. nov.; male from Morocco, Fès-Meknès, Kef el Ghar (ZFMK Ar 24685) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views; numbers 1–3 denote pointed processes of appendix. Abbreviations: a, putative appendix; e, embolus; hp, dorsal hinged process; ps, proximal bulbal sclerite; u, putative uncus. Scale bars: 0.3 mm.

Figure 66. 

Micropholcus ghar Huber, sp. nov.; from Morocco, Fès-Meknès, Kef el Ghar A, B male chelicerae, frontal and lateral views (ZFMK Ar 24685) C cleared female genitalia, dorsal view (ZFMK Ar 24686); arrows point at distinctive membranous structures. Scale bars: 0.3 mm.

Figure 67. 

Micropholcus ghar Huber, sp. nov.; female from Morocco, Fès-Meknès, Kef el Ghar (ZFMK Ar 24686) A epigynum, ventral view B, C cleared female genitalia, ventral and dorsal views. Scale bars: 0.3 mm.

Male (holotype). Measurements. Total body length 3.6, carapace width 1.2. Distance PME-PME 200 µm; diameter PME 85 µm; distance PME-ALE 25 µm; distance AME-AME 20 µm; diameter AME 45 µm. Leg 1: 37.6 (9.7 + 0.6 + 9.7 + 15.9 + 1.7), tibia 2: 6.8, tibia 3: 4.2, tibia 4: 5.7; tibia 1 L/d: 84; diameters of leg femora (at half length) ~ 0.13; of leg tibiae 0.11–0.12.

Colour (in ethanol). Prosoma and legs mostly pale ochre-yellow, carapace with light brown marks, ocular area and clypeus without darker pattern, sternum with brown margins and three light brown marks posteriorly; legs with slightly darkened patellae, tibia-metatarsus joints not darkened; abdomen monochromous pale grey to whitish.

Body. Habitus as in Fig. 4F. Ocular area raised (distinct in frontal view; Fig. 5C). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.80/0.60), unmodified. Abdomen oval, approximately twice as long as wide. Gonopore with four epiandrous spigots (Fig. 10E). Spinnerets as in Fig. 9H, I.

Chelicerae. As in Fig. 66A, B; with pair of long distal frontal apophyses, each with two cone-shaped hairs (Fig. 6F, G); and two pairs of smaller proximal processes.

Palps. As in Fig. 64; coxa unmodified; trochanter with retrolateral-ventral apophysis provided with terminal modified hair (Fig. 9D); femur cylindrical with distinct ventral process proximally; femur-patella joints shifted toward prolateral side; tibia-tarsus joints slightly shifted toward retrolateral side. Procursus (Figs 8D, 65A–C) proximally with sclerotised prolateral ridge; at half length with strong prolateral-ventral sclerotised ridge or process; distally with dorsal hinged process; tip of procursus partly sclerotised and apparently also hinged against proximal part. Genital bulb (Figs 8E, F, 65D, E) with strong proximal sclerite; putative appendix with three pointed processes directed towards bulbous part, distally widened and membranous, with fringed membrane; putative uncus flat with series of pointed processes and one long curved process; and mostly semi-transparent embolus.

Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs (many hairs missing in holotype but confirmed in other males); retrolateral trichobothrium of tibia 1 at 5%; prolateral trichobothrium absent on tibia 1; tarsus 1 with > 20 pseudosegments, distally distinct.

Variation (male). Tibia 1 in 18 males (incl. holotype): 6.2–10.2 (mean 8.1). While most elements of the bulbal processes (and procursus) appear to be very consistent, there is substantial variation in the row of pointed processes on the uncus. The number of larger processes ranges from two to four; the smaller processes may be absent or replaced by a single (sometimes larger) process; several males were asymmetric in this respect.

Female. In general very similar to male but abdomen often much wider. Tibia 1 in 14 females: 6.0–9.1 (mean 7.3). Epigynum (Figs 10F, 67A) anterior plate divided into two sections, anterior section weakly sclerotised, with curved ridges and hairs; posterior section smooth, medially whitish, laterally brown to black, i.e., heavily sclerotised; small knob-shaped process (Fig. 11C) between posterior and anterior parts; posterior epigynal plate short and very indistinct. Internal genitalia (Figs 66C, 67B, C) with pair of small oval pore plates, distinctive median sclerite, and pair of large membranous structures laterally.

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

Known from two localities in Morocco, both in Fès-Meknès Region (Fig. 13D). We could not examine the single male specimen mentioned in Lecigne et al. (2023: 71), originating from Tazekka National Park, Ghar Admam, 34.0278°N, 4.1509°W. However, photographs of the male palp kindly provided by S. Lecigne leave little doubt that this is the same species.

The spiders were very abundant within the first ~ 100 m of the cave; no specimens were seen outside the cave or in deeper sections. They built their fine and slightly domed webs close to the floor, often under small rock overhangs. They were hanging in the apex of the dome rather than sitting on the rock. At disturbance, they bounced slightly and walked towards the rock.

Holotype. Morocco – Béni Mellal-Khénifra • ♂; Imi n’Ifri; 31.724°N, 6.971°W; 1050 m a.s.l.; 26 Sep. 2018; B.A. Huber leg.; ZFMK Ar 24687.

Morocco – Béni Mellal-Khénifra • 5 ♂♂, 5 ♀♀; same collection data as for holotype; ZFMK Ar 24688 to 24689 • 2 ♂♂, 1 ♀, in pure ethanol; same collection data as for holotype; ZFMK Mor104 • 4 ♂♂, 4 ♀♀; near Sidi Ben Daoud; 32.5347°N, 6.1285°W; 700 m a.s.l.; 25 Sep. 2018; B.A. Huber leg.; ZFMK Ar 24690 to 24691 • 1 ♂, 1 ♀, 2 juvs, in pure ethanol; same collection data as for preceding; ZFMK Mor102 • 4 ♂♂, 3 ♀♀, 1 juv.; W of El Ksiba; 32.560°N, 6.053°W – 32.562°N, 6.050°W; 950 m a.s.l.; 25 Sep. 2018; B.A. Huber leg.; ZFMK Ar 24692 to 24693 • 1 ♀, 1 juv., in pure ethanol; same collection data as for preceding; ZFMK Mor103 • 1 ♀; Jbel Bou-Guergour, Ghar-el-Ghazi; 32.869°N, 5.689°W (?); 970 m a.s.l.; 26 May 2001; C. Ribera leg.; ZFMK Ar 24700.

Easily distinguished from known congeners by whitish dorsal process of male palpal tarsus (asterisk in Fig. 69C; absent in congeners), by large and prominent flat ventral process of procursus (arrowed in Fig. 69C; much smaller or absent in congeners), by complex tip of procursus with distinctive dorsal spine (Fig. 69A–C), by rounded uncus (Fig. 69E, F; similar only in M. agadir), by very small appendix (larger and more complex in Moroccan congeners), by long prominent embolus (Fig. 69E, F; in Moroccan congeners shorter and in prolateral view largely hidden behind uncus and appendix), by pair of dark internal structures visible at anterior margin of epigynum (Fig. 71A; absent in congeners), by distinctive m-shaped dorsal arc in female internal genitalia (Fig. 71C), and by very narrow (short) sclerotised band posteriorly on epigynum carrying epigynal ‘knob’ (Fig. 71A).

Figure 68. 

Micropholcus khenifra Huber, Lecigne & Lips, sp. nov.; male from Morocco, Béni Mellal-Khénifra, Imi n’Ifri (ZFMK Ar 24688). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.5 mm.

Figure 69. 

Micropholcus khenifra Huber, Lecigne & Lips, sp. nov.; male from Morocco, Béni Mellal-Khénifra, Imi n’Ifri (ZFMK Ar 24688) A–C left procursus in prolateral, dorsal, and retrolateral views; bold arrow in A points at pointed process that is absent in males from near Sidi Ben Daoud and from W of El Ksiba; asterisk in C marks distinctive whitish process of tarsus; bold arrow in C points at flat ventral process of procursus D tip of palpal trochanter apophysis E, F left genital bulb in prolateral and retrolateral views. Abbreviations: a, putative appendix; e, embolus; ps, proximal bulbal sclerite; u, putative uncus. Scale bars: 0.3 mm (A–C, E, F); 0.05 mm (D).

Figure 70. 

Micropholcus khenifra Huber, Lecigne & Lips, sp. nov.; from Morocco, Béni Mellal-Khénifra, Imi n’Ifri A, B male chelicerae, frontal and lateral views (ZFMK Ar 24688) C cleared female genitalia, dorsal view (ZFMK Ar 24689). Scale bars: 0.3 mm.

Figure 71. 

Micropholcus khenifra Huber,Lecigne & Lips, sp. nov.; female from Morocco, Béni Mellal-Khénifra, near Sidi Ben Daoud (ZFMK Ar 24689) A epigynum, ventral view B, C cleared female genitalia, ventral and dorsal views. Abbreviations: aep, anterior epigynal plate; k, epigynal ‘knob’; pep, posterior epigynal plate. Scale bars: 0.5 mm.

Male (holotype). Measurements. Total body length 3.9, carapace width 1.5. Distance PME-PME 205 µm; diameter PME 90 µm; distance PME-ALE 30 µm; distance AME-AME 20 µm; diameter AME 50 µm. Leg 1: 34.5 (8.7 + 0.6 + 9.0 + 14.4 + 1.8), tibia 2: 6.4, tibia 3: 4.0, tibia 4: 5.3; tibia 1 L/d: 75; diameters of leg femora (at half length) 0.14–0.15; of leg tibiae 0.12.

Colour (in ethanol). Prosoma and legs mostly ochre-yellow, carapace with brown median mark, ocular area and clypeus without darker pattern, sternum with brown margins; legs with slightly darkened patellae, anterior femora ventrally only very slightly darkened, tibia-metatarsus joints not darkened; abdomen monochromous pale grey.

Body. Habitus as in Fig. 4G. Ocular area raised (distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.88/0.72), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 70A, B; with pair of strong distal frontal apophyses, each with two cone-shaped hairs; and two pairs of smaller proximal processes.

Palps. As in Fig. 68; coxa unmodified; trochanter with ventral apophysis provided with terminal modified hair (Fig. 69D); femur cylindrical, proximally with small retrolateral process and larger prolateral-ventral process; femur-patella joints shifted toward prolateral side; tibia very large relative to femur; tibia-tarsus joints not shifted to one side; tarsus with cone-shaped light dorsal process carrying tarsal organ. Procursus (Fig. 69A–C) proximally with sclerotised prolateral ridge; proximal half with flat ventral process (arrowed in Fig. 69C), distally divided into dorsal and ventral parts and complex hinged structure between them (mostly on prolateral side), with pointed process originating from membranous connection between dorsal part and hinged process. Genital bulb (Fig. 69E, F) with strong proximal sclerite; putative appendix small; putative uncus flat with retrolateral process; and long, partly sclerotised embolus.

Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs; retrolateral trichobothrium of tibia 1 at 9%; prolateral trichobothrium absent on tibia 1; tarsus 1 with > 30 pseudosegments, distally distinct.

Variation (male). Tibia 1 in 14 males (incl. holotype): 6.9–9.2 (mean 8.2). There was very slight variation in palpal structures among localities: in males from near Sidi Ben Daoud and from W of El Ksiba, the uncus was slightly rounder, the appendix slightly larger, and one small, pointed element of the dorsal part of the procursus (arrowed in Fig. 69A) was absent. The number of modified hairs on the frontal cheliceral apophyses was two or three, and was sometimes asymmetrical (as in Fig. 70A).

Female. In general very similar to male. Tibia 1 in 12 females: 7.1–8.4 (mean 7.7). Epigynum (Fig. 71A) anterior plate mostly light, anteriorly with pair of dark internal structures variably visible in untreated specimens, posteriorly with narrow darker transversal band and median ‘knob’; posterior epigynal plate short and very indistinct. Internal genitalia (Figs 70C, 71B, C) with pair of small oval pore plates and distinctive ventral and dorsal anterior arches and sclerites.

The species name is derived from Béni Mellal-Khénifra, the region in Morocco where all available specimens were collected; noun in apposition.

Known from several localities in Morocco, all in Béni Mellal-Khénifra Region (Fig. 13D).

At Imi N’ifri (Fig. 14G) and west of Ksiba, the spiders were found in small cavities of rocks, on the undersides of very large boulders, and in small caverns at ground level. Near Sidi Ben Daoud, the spiders were found in a small cave from which a brook emerged. The spiders sat flat on the rock and appeared very unwilling to leave the spot upon disturbance. At all localities, M. khenifra sp. nov. was found in close proximity with Holocnemus reini.

Holotype. Philippines – Mindanao • ♂; Bukidnon Province, Central Mindanao University, Faculty Hill; 7.852°N, 125.048°E; 330 m a.s.l.; on rocks in degraded forest; 10 Feb. 2014; B.A. Huber leg.; ZFMK Ar 24694.

Philippines – Mindanao • 7 ♂♂, 10 ♀♀, 1 juv. (1 ♂, 1 ♀ used for SEM); same collection data as for holotype; ZFMK Ar 24695 to 24696 • 2 ♂♂, 3 ♀♀, in pure ethanol; same collection data as for holotype; ZFMK Phi 273 • 3 ♂♂, 2 ♀♀; Barangay San Jose, Blue Water Cave; 7.705°N, 125.035°E; 230 m a.s.l.; at rocks at cave entrance; 16 Feb. 2014; B.A. Huber leg.; ZFMK Ar 24697 • 2 ♂♂, 2 ♀♀, 1 juv., in pure ethanol; same collection data as for preceding; ZFMK Phi 250 • 7 ♀♀; Barangay San Jose, Kabyaw Cave; ~ 7.704°N, 125.038°E; ~ 260 m a.s.l.; at rocks at cave entrance; 16 Feb. 2014; B.A. Huber leg.; ZFMK Ar 24698.

Easily distinguished from known congeners by unusually long proximal frontal apophyses on male chelicerae (Fig. 74B); by long ventral process of palpal femur (Fig. 72C); by long rod-shaped putative appendix (Fig. 73D, E), and by distinctive shapes of processes on procursus (Fig. 73A–C; in particular large flat dorsal process). Female genitalia very simple externally (Fig. 75A), distinguished from congeners by absence of external knob (Fig. 10H) and by distinctive internal structures (round pore plates; m-shaped dorsal arch; concentric ventral arches; distinctive median membranous structures posteriorly).

Figure 72. 

Micropholcus bukidnon Huber, sp. nov.; male from Philippines, Mindanao, Central Mindanao University (ZFMK Ar 24695); left palp in prolateral (A), dorsal (B), and retrolateral (C) views; arrow in C points at distinctive ventral process on femur. Scale bar: 0.3 mm.

Figure 73. 

Micropholcus bukidnon Huber, sp. nov.; male from Philippines, Mindanao, Central Mindanao University (ZFMK Ar 24695) A–C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views. Abbreviations: a, putative appendix; e, embolus; ps, proximal bulbal sclerite. Scale bars: 0.3 mm.

Figure 74. 

Micropholcus bukidnon Huber, sp. nov.; from Philippines, Mindanao, Central Mindanao University A, B male chelicerae, frontal and lateral views (ZFMK Ar 24695) C, D cleared female genitalia, ventral and dorsal views (ZFMK Ar 24696). Scale bars: 0.3 mm.

Figure 75. 

Micropholcus bukidnon Huber, sp. nov.; females from Philippines, Mindanao, Central Mindanao University. (ZFMK Ar 24696) A abdomen, ventral view B, C epigyna of two females, ventral views D, E cleared genitalia, ventral and dorsal views. Scale bars: 0.5 mm (A); 0.3 mm (B–E).

Male (holotype). Measurements. Total body length 2.8, carapace width 1.1. Leg 1: 28.1 (6.7 + 0.5 + 7.1 + 12.4 + 1.4), tibia 2: 4.5, tibia 3: 2.9, tibia 4: 3.8; tibia 1 L/d: 77. Distance PME-PME 190 µm, diameter PME 100 µm, distance PME-ALE ~ 30 µm; distance AME-AME 30 µm, diameter AME 15 µm.

Colour (in ethanol). Carapace pale ochre with dark median band widening posteriorly, ocular area and clypeus only slightly darkened; sternum pale ochre with narrow dark margins; legs ochre to light brown, with dark brown patellae and tibia-metatarsus joints; abdomen monochromous pale grey.

Body. Habitus as in Fig. 4H; ocular area slightly raised (Fig. 5E); carapace without median furrow; clypeus unmodified; sternum wider than long (0.65/0.55), unmodified. Gonopore of scanned male with five epiandrous spigots (Fig. 10G). Anterior lateral spinnerets with one strongly widened, one pointed, and six cylindrically shaped spigots (Fig. 9J).

Chelicerae. As in Fig. 74A, B; proximally with pair of long frontal apophyses and pair of short lateral processes directed towards proximal, distally with pair of dark apophyses near laminae, each provided with five modified (globular) hairs (Fig. 6H).

Palps. As in Fig. 72; coxa unmodified; trochanter with retrolateral apophysis, tip of apophysis without modified hair (Fig. 9E); femur with low retrolateral hump proximally and with distinctive ventral process; procursus (Figs 8G, 73A–C) very complex distally, with apparently hinged ventral structures and large dorsal flap; genital bulb (Figs 8H, 73D, E) with strong proximal sclerite, with long weakly sclerotised embolus and heavily sclerotised cylindrical putative appendix with proximal round protrusion and short subdistal branch.

Legs. Without spines and curved hairs; without sexually dimorphic short vertical hairs; retrolateral trichobothrium on tibia 1 at 10%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 with ~ 15 pseudosegments, only distally distinct. Tarsus 4 comb-hairs as in Fig. 12H.

Variation (male). Tibia 1 in nine other males: 5.4–7.3 (mean 6.5); specimens from Barangay San Jose have consistently shorter legs than specimens from Faculty Hill (5.4–5.7 versus 6.6–7.3).

Female. In general similar to male; eye triads at almost same distance (PME-PME: 170 µm; Fig. 5F). Dark band on carapace in some females posteriorly not widened. Tibia 1 in 19 females: 4.3–6.0 (mean: 5.2). As in males, specimens from Barangay San Jose have consistently shorter legs than specimens from Faculty Hill (4.3–5.2 versus 5.4–6.0). Epigynum very simple (Figs 10H, 75A–C), weakly sclerotised, without external ‘knob’; internal genitalia (Figs 74C, D, 75D, E) with round pore plates, m-shaped dorsal arch, concentric ventral arches, and distinctive median membranous structures posteriorly.

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

Known from three localities (two of them very close to each other) in central Mindanao, Philippines (Fig. 13B).

The spiders were found on rocks, either on the undersides of large rocks with sufficient space to the ground, or in small depressions of near-vertical rock-surfaces (Fig. 14H). Two egg sacs contained 11 and 25 eggs, respectively, with an egg diameter of 0.54–0.57 mm (Huber and Eberle 2021).