Artema ghubrat Huber, 2019

Huber, Bernhard A. & Carvalho, Leonardo S., 2019, Filling the gaps: descriptions of unnamed species included in the latest molecular phylogeny of Pholcidae (Araneae), Zootaxa 4546 (1), pp. 1-96 : 11-14

Artema ghubrat Huber sp. n.

Figs 3–4 , 9–10 , 15–16 , 21–22 , 26 , 29, 31 , 35–36

Artema sp. a: Aharon et al. 2017: 44 , fig. 170 (♀).

Artema sp. n. “Om42”: Huber 2018b: 4.

Type material. OMAN: ♂ holotype, ZFMK ( Ar 20593), Ad Dakhiliyah, between Tanuf and Al Hamra, Al Ghubrat Cave (23.0718°N, 57.3680°E), lower entrance, in cave, 665 m a.s.l., 15.ii.2018 (B.A. Huber) .

Other material examined. OMAN: 6♂ 3♀, ZFMK (Ar 20594) and 1♀ in pure ethanol, ZFMK ( Om 104), same data as holotype . 1♀, NHMW, Al Ghubrat Cave , same entrance (“ Al Ghubrat, Quellhöhle ”), xi.2001 (Sattmann) . 2♂ 5♀, ZFMK ( Ar 20595), Al Ghubrat Cave (23.0723°N, 57.3679°E), upper entrance, in cave, 675 m a.s.l., 15.ii.2018 (B.A. Huber) .

Note. The coordinates of Al Ghubrat Cave in Aharon et al. (2017) are slightly wrong (4.5 km NE). At that time we did not know the precise location of this cave.

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

Diagnosis. Pale species without dark abdominal marks ( Figs 3–4 ), distinguished from known congeners by male chelicerae ( Figs 21–22 ; median ridges leading to distal apophyses, pair of rounded lateral projections), and by shape of epigynum ( Fig. 31 ; simple anterior plate wider than long, anterior epigynal projections barely visible). From most species also by combination of procursus distally without light notch in dorsal view ( Fig. 9 ), and genital bulb with large rounded process c ( Figs 10 , 15–16 ).

Description. Male (holotype). MEASUREMENTS. Total length 8.1, carapace width 3.1. Distance PME-PME 190 µm; diameter PME 160 µm; distance PME-ALE 30 µm; distance AME-AME 40 µm, diameter AME 140 µm. Leg 1: 61.4 (15.7 + 1.3 + 17.2 + 24.3 + 2.9), tibia 2: 13.5, tibia 3: 9.7, tibia 4: 12.1; tibia 1 L/d: 57.

COLOR (in ethanol). Carapace pale ochre-yellow, slightly darker pit and light brown ocular area; clypeus with indistinct light brown median band and dark brown rim; sternum ochre-yellow with light brown margins; legs ochre-yellow, patellae slightly darker, femora 1 proximally red-brown. Abdomen monochromous pale gray.

BODY. Habitus as in Fig. 3 . Ocular area barely elevated, on posterior part with ~20 very strong hairs. Deep thoracic pit behind ocular area, without thoracic furrow in posterior part of carapace. Clypeus unmodified except for slightly thickened brown rim. Sternum wider than long (2.1/1.4), unmodified. Gonopore with four epiandrous spigots.

CHELICERAE. As in Figs 21–22 , with several sclerotized cone-shaped hairs in distinctive arrangement, with median ridges leading to distal apophyses and pair of rounded lateral projections; with very fine and barely visible stridulatory ridges.

PALPS. In general very similar to known congeners ( Fig. 29 ); coxa unmodified, trochanter ventrally slightly projecting and strongly sclerotized, femur strongly widened, with retrolateral apophysis proximally pointing towards ventral, with stridulatory pick (modified hair) prolaterally near joint to trochanter, patella very short, ventrally closed, i.e. not reduced; tibia retrolateral trichobothrium in very proximal position; procursus with distinct dorsal apophysis and ventral pocket in very proximal position, distally widened, without light notch in dorsal view ( Fig. 9 ); genital bulb with short membranous embolus accompanied by two processes (processes a and b in Aharon et al. 2017), with distinct and large process c and small process d ( Figs 10 , 15–16 ).

LEGS. Without spines and curved hairs, few vertical hairs; regular mechanoreceptive sensilla either thick and variably long (~0.15–1.5) or thin and short (~0.08–0.15); retrolateral trichobothrium of tibia 1 at 9%; prolateral trichobothrium present on all tibiae; tarsus 1 with ~15–20 pseudosegments, barely visible.

Male (variation). Tibia 1 in 8 other males: 14.1–16.8 (mean 15.7).

Female. In general similar to male ( Fig. 4 ) but with distinct stridulatory ridges on chelicerae, clypeus rim not brown, and femora 1 proximally not red-brown. Tibia 1 in 8 females: 10.4–14.0 (mean 12.4). Entire epigynal area ( Fig. 31 ) strongly protruding, anterior plate on frontal side of epigynal protuberance and posterior plate on rear side; anterior plate rectangular, dark brown laterally, lighter and slightly bulging medially; posterior plate simple, very wide. Anterior epigynal projections barely visible. Internal genitalia simple, with pair of elongated pore plates in transversal position ( Figs 26 , 35–36 ).

Distribution. Known from type locality only ( Fig. 342 ).

Natural history. This species was only found in total darkness in the cave, while the cave entrance area was occupied by Artema bahla (and an unnamed species of the genus Crossopriza Simon, 1893 ). Within the cave, the spiders were very abundant, but often too high to reach or hidden deep in rock cavities. Their webs appeared much less conspicuous than those of epigean congeners.

Figures

FIGURE 342. Known distributions of the three new species of Artema and of Magana velox sp. n.; UAE, United Arab Emirates.

FIGURES 1–6. Artema spp., live specimens. 1–2. A. bahla sp. n., male from Ibri-Rusdaq and female with egg-sac from Al Kittan Cave. 3–4. A. ghubrat sp. n., male and female with egg sac, Al Ghubrat Cave. 5–6. A. dhofar sp. n., male and female from Suhur Cave.

FIGURES 7–12. Artema spp., procursi in dorsal views, and genital bulbs in dorsal views. 7–8. A. bahla sp. n. (ZFMK, Ar 20587). 9–10. A. ghubrat sp. n. (ZFMK, Ar 20594). 11–12. A. dhofar sp. n. (ZFMK, Ar 20596). a, b, c, bulbal processes a–c; da, dorsal apophysis; em, embolus; n, light notches. Scale line: 0.5 (all figures at same scale).

FIGURES 13–18. Artema spp., genital bulbs in prolateral (13, 15, 17) and prolateral-ventral (14, 16, 18) views. 13–14. A. bahla sp. n. (ZFMK, Ar 20587). 15–16. A. ghubrat sp. n. (ZFMK, Ar 20594). 17–18. A. dhofar sp. n. (ZFMK, Ar 20596). a, b, c, d, bulbal processes a–d; em, embolus. Scale line: 0.5 (all figures at same scale).

FIGURES 19–24. Artema spp., male chelicerae in frontal and lateral views. 19–20. A. bahla sp. n. (ZFMK, Ar 20587). 21–22. A. ghubrat sp. n. (ZFMK, Ar 20594); arrows point at distinctive ridge and at lateral projection. 23–24. A. dhofar sp. n. (ZFMK, Ar 20596). Scale lines: 0.5.

FIGURES 25–27. Artema spp., cleared female genitalia in dorsal views. 25. A. bahla sp. n. (ZFMK, Ar 20587); pp, pore plates. 26. A. ghubrat sp. n. (ZFMK, Ar 20594). 27. A. dhofar sp. n. (ZFMK, Ar 20597). Scale lines: 0.5.

FIGURES 28–32. Artema spp., left male palps, retrolateral views (at same scale), and epigyna, ventral views. 28, 32. A. dhofar sp. n. (ZFMK, Ar 20596–97). 29, 31. A. ghubrat sp. n. (ZFMK, Ar 20594). 30. A. bahla sp. n. (ZFMK, Ar 20588); arrows point at distinctive deep cavities; aep, anterior epigynal projection. Scale lines: 1.0.

FIGURES 33–38. Artema spp., cleared female genitalia in ventral and dorsal views. 33–34. A. bahla sp. n. (ZFMK, Ar 20587). 35–36. A. ghubrat sp. n. (ZFMK, Ar 20594). 37–38. A. dhofar sp. n. (ZFMK, Ar 20597). Scale lines: 1.0.