Crossopriza dhofar sp. nov.

urn:lsid:zoobank.org:act: 52766710-5651-40D5-8657-3E484C5AB946

Figs 352, 396–398, 450–474

Diagnosis

Easily distinguished from all described congeners by details of male palp (Figs 453–457; procursus tip with ventral sclerite and two further pointed processes; bulbal sclerite with two simple pointed processes), by male chelicerae (Figs 458–459; modified hairs on frontal face), and female genitalia (Figs 460–466, 473–474; pair of large pockets; large internal median sclerite; pair of lateral internal sclerites) (see also Remark below).

Remark

A very similar undescribed species occurs in Yemen (Seyoun, 15.95° N, 48.78°E). It shares the distinctive configuration of the distal procursus and bulb elements as well as the presence of modified hairs proximally on the male chelicerae. However, the shapes and positions of these elements differ from C. dhofar sp. nov. The species is not formally described because the female is unknown. A single male specimen and one juvenile are deposited in ZFMK Ar 22409–10.

Etymology

The species name refers to the type locality; noun in apposition.

Type material

Holotype OMAN – Dhofar • ♂; Ain Razad cave; 17.1301° N, 54.2364° E; 115 m a.s.l.; 22 Feb. 2018; B.A. Huber leg.; in cave; ZFMK Ar 22411.

Other material examined

OMAN – Dhofar • 1 ♂, 2 ♀♀; same collection data as for holotype; ZFMK Ar 22412 • 1 ♀, 1 juv. (in pure ethanol); same collection data as for holotype; ZFMK Om 130 • 12 ♀♀, 3 juvs (partly used for SEM); Wadi Nahiz; 17.140° N, 54.123° E; 140 m a.s.l.; 21 Feb. 2018; B.A. Huber leg.; under rocks; ZFMK Ar 22413 • 1 ♀, 4 juvs (in pure ethanol); same collection data as for preceding; ZFMK Om 125 • 1 ♂, 10 ♀♀; same collection data as for preceding; 26 Feb. 2018; Ar 22493 • 1 ♀, 2 juvs; same collection data as for preceding; ZFMK Om 143 • 1 ♂, 3 ♀♀; Ain Athoom; 17.116° N, 54.369° E; 290 m a.s.l.; 28 Feb. 2018; B.A. Huber leg.; under rocks in wadi; ZFMK Ar 22414 • 1 ♀ (in pure ethanol); same collection data as for preceding; ZFMK Om 148 • 4 ♀♀; Wadi Darbat; 17.09° N, 54.45° E; 200 m a.s.l.; 23 Feb. 2018; B.A. Huber leg.; ZFMK Ar 22415 • 1 ♀ (in pure ethanol); same collection data as for preceding; ZFMK Om 132 • 1 ♀; Tayq Cave; 17.182° N, 54.534° E; 790 m a.s.l.; 23 Feb. 2018; B.A. Huber leg.; among rocks near cave; ZFMK Ar 22416 • 1 ♀ (in pure ethanol); same collection data as for preceding; ZFMK Om 134 • 1 ♀; Wadi Shalyon; 17.1844° N, 54.9538° E; 360 m a.s.l.; 1 Mar. 2018; B.A. Huber leg.; under rocks in wadi; ZFMK Ar 22417 • 2 ♀♀; NE of Rawiyyah; 17.4733° N, 54.1195° E; 540 m a.s.l.; 27 Feb. 2018; B.A. Huber leg.; among palms near ground; ZFMK Ar 22418 • 1 ♀, 1 juv. (in pure ethanol); same collection data as for preceding; ZFMK Om 145 • 3 juvs (in pure ethanol); E of Thumrait; 17.670° N, 54.163° E; 460 m a.s.l.; 27 Feb. 2018; B.A. Huber leg.; among rocks and in low palms near ground; ZFMK Om 144 • 1 ♂, 2 ♀♀, 1 juv.; Shaat sinkhole, in wadis leading to sinkhole; 16.774° N, 53.587° E; 850 m a.s.l.; 24 Feb. 2018; B.A. Huber leg.; ZFMK Ar 22419 • 1 ♂, 2 ♀♀, 1 juv.; same collection data as for preceding; 25 Feb. 2018; Ar 23863.

Description

Male (holotype)

MEASUREMENTS. Total length 3.3, carapace width 1.1. Distance PME–PME 80 µm; diameter PME 80 × 90 µm; distance PME–ALE 30 µm; diameter AME 75 µm; distance AME–AME 20 µm. Leg 1: 28.3

(7.9 + 0.5 + 7.8 + 10.3 + 1.8), tibia 2: 5.1, tibia 3: 4.1, tibia 4: 4.4; tibia 1 L/d: 74; femora 1–4 diameters: 0.14, 0.11, 0.11, 0.11.

COLOR (in ethanol). Carapace ochre-yellow, with light brown median band including ocular area; clypeus not darkened; sternum densely covered with dark brown spots; legs ochre-yellow, without darker rings, with black marks on femora and (few) on tibiae; abdomen gray, with dorsal pattern of dark marks among many internal whitish marks; ventrally with distinct black pattern (disrupted median band), three longitudinal bands behind gonopore.

BODY. Habitus as in Fig. 396. Ocular area slightly raised. Shallow but wide thoracic pit and pair of furrows diverging from pit toward posterior margin. Clypeus unmodified, only rim slightly more sclerotized than in female. Sternum wider than long (0.80/0.55), unmodified. Abdomen elongated and pointed above spinnerets.

CHELICERAE. As in Figs 458–459, with pair of distal lateral apophyses provided with one modified cone-shaped hair each, two pairs of large conical hairs frontally near median line, and pair of smaller modified hairs more proximally (slightly asymmetric); distance between tips of modified hairs on lateral apophyses: 405 µm; with distinct lateral stridulatory ridges.

PALPS. As in Figs 450–452; coxa with very low retrolateral hump; trochanter barely modified; femur distally strongly widened, with rounded ventral protrusion, proximally with prolateral stridulatory pick, without retrolateral transversal line, without retrolateral proximal process; femur-patella joints shifted toward prolateral side; tibia large relative to femur; tibia-tarsus joints slightly shifted toward retrolateral side; tarsus without macrotrichia; procursus (Figs 453–454) slightly curved towards ventral, short, long dorsal hairs not curved, with two strong humps proximally on prolateral side, ventral hump densely set with long hairs; procursus tip complex, with ventral hinged sclerite accompanied by flat parallel sclerite, pointed dorsal sclerite, and median partly membranous elements; genital bulb (Figs 455–457) with simple basal sclerite connected to distal (main) sclerite, sperm duct opening not seen; distal sclerite with distinctive ventral process, smaller prolateral process, and partly semitransparent pointed tip.

LEGS. Femur 1 with single row of ~10 ventral spines; without curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 2.5%; prolateral trichobothrium absent on tibia 1, present on other leg tibiae; tarsi without regular pseudosegments (except for 2–3 at tip).

Male (variation)

Tibia 1 in six males (incl. holotype): 6.4–9.9 (mean 8.2). Larger males with more spines of femur 1 (~ 23 in largest male); sternum sometimes uniformly dark, almost black; ventral abdominal pattern slightly variable, three longitudinal bands sometimes fused; frontal hairs on chelicerae slightly variable, but usually with two pairs of strong hairs and 1–3 more proximal pairs of smaller hairs, often asymmetric. Males from Shaat sinkhole with slightly shorter dorsal process at tip of procursus.

Female

In general similar to male (Figs 397–398) but without spines on legs, with very indistinct stridulatory files on chelicerae (Fig. 469; barely visible in dissecting microscope), and with stridulatory organ consisting of pair of weakly sclerotized but distinct processes posteriorly on carapace (arrow in Fig. 468) and pair of light brown plates anteriorly on abdomen. Tarsal organ capsulate (Fig. 472); ALS with one widened spigot and one pointed spigot (Fig. 471). Tibia 1 in 36 females: 5.2–8.7 (mean 6.5). Epigynum as in Figs 462–463 and 473–474, protruding area in anterior part whitish, posterior part with triangular brown plate; with pair of large pockets (250 µm apart); internal median sclerite (pouch?) clearly visible in untreated specimens; posterior plate short but wide. Internal genitalia (Figs 460–461, 464–466) with oval pore plates converging anteriorly, with pair of distinct lateral sclerites embedded in membrane, dorsal arc simple, ventral arc with strong median sclerite (pouch?) of unknown function.

Natural history

Most specimens were found on the undersides of rocks on the floor. In Wadi Nahiz, they shared this microhabitat with an undescribed Buitinga (generic assignment tentative)and an undescribed Micropholcus. Relatively few males were found (Wadi Nahiz: one male vs 24 females; all other localities combined: five males vs 22 females), suggesting that the species might be seasonal. At Ain Razad, this species shared a small cavity in the deepest part of a shallow cave with Smeringopus lineiventris Simon, 1890 and Artema dhofar Huber, 2019. At Shaat sinkhole, the spiders were found in small holes in the karstic rocks, sitting on small silk mats directly on the rock. In the desert NE of Rawiyyah and E of Thumrait, the spiders were found in rock crevices and hidden among the spiny leafs of palm bushes close to the ground.

Distribution

Widespread in the Dhofar Region of Oman, where it is the only known representative of Crossopriza (Fig. 352).