Raveniola ambardzumyani, Marusik & Zonstein, 2021

Marusik, Yuri M. & Zonstein, Sergei L., 2021, Description of Raveniola ambardzumyani n. sp. from Armenia (Araneae: Nemesiidae), Israel Journal of Entomology (Oxford, England) 51 (1), pp. 93-101 : 96-98

Raveniola ambardzumyani n. sp.

( Figs 1–7, 11)

LSID: urn:lsid:zoobank.org:act:E44C3C21-E8C5-4968-A5BB-D39F076B15BC .

Etymology: The species is named in honour of Vartan Zh. Ambardzumyan (Yerevan, Armenia), who helped to arrange an expedition, during which the type series was collected.

Diagnosis: The structure of the spermathecae in the new species somewhat resembles that in R. zaitzevi (Charitonov, 1948) , and is more similar to their structure in R. niedermeyeri (Brignoli, 1972) and R. vonwicki Zonstein, 2000 .The new species can be distinguished from all three in the shape of their three-head receptacular branches arising from a narrow common base ( Figs 6, 7 cf. Figs 8–10).

Description: Female (holotype). Total length 17.8. Habitus as in Fig. 1.

Colour (in alcohol): Carapace, palps and legs light to medium ginger brown; eye tubercle not darkened, eyes are encircled each with obscure brownish area; chelicerae dorsally dark chestnut brown, ventrally dark orange; venter brownish orange (sternum and labium darker, maxillae lighter, coxae I–IV even paler), abdomen dorsally medium brownish grey with slighter darker and poorly distinct brownish chevron-like pattern; ventral part abdomen and spinnerets light yellowish brown.

Cephalothorax dorsally and ventrally as in Figs 2 and 3, respectively. Carapace 7.01 long, 6.05 wide. Cephalic region slightly elevated over thoracic portion of carapace; thoracic fovea nearly straight. Clypeus narrow, equal in length to AME diameter. Eye tubercle weakly developed with slightly raised AME ( Fig. 4). Eye diameter and interdistances: AME 0.14(0.20), ALE 0.12, PLE 0.08, PME absent, AME–AME 0.16(0.10), AME–ALE 0.19(0.16), ALE–PLE 0.17, PLE–PLE 0.91. Chelicerae without rastellum. Cheliceral furrow with 10 promarginal teeth and 10–11 uniformly very small mesobasal denticles. Labium 0.71 long, 1.25 wide. Sternum 3.29 long, 2.98 wide. Maxillae each with 5–6 large cuspules along probasal heel.

Palp and legs: Spines (all femora with 3–5 thin and long dorsal spines alongside midline; palpal patella, patellae I–II and tarsi I–IV aspinose): Palp: femur pd1; tibia p1–1, v3(2)–3(2)–3; tarsus v3–1–2. Leg I: femur pd1; tibia p1–0, v2(1)–1–2(1)–3; metatarsus v2–2(0)–1–2. Leg II: femur pd1–1; tibia p0–1, v3(2)–1–1–3; metatarsus v2–2–2. Leg III: femur pd1–1, rd1–1; patella p1, r1; tibia d1–0, p1–1, r1–1, v2–2–3; metatarsus p1–1–1, pd1–1–1, r1–1, rd1–1–1, v2–2–3. Leg IV: femur pd0–0–1, rd0–0–1; patella p1, r1; tibia d1–0–0, p0–1–1, r1–1–1, v2–2–3; metatarsus d0–1–0, p1–1–1, r1–1–1–1, v2–1–2–3. Trichobothria: 2 rows of 9–11 each on tibiae, 13–15 on metatarsi, 13–14 on tarsi, 10 on palpal tarsus. Scopula entire and distal on metatarsi I–II, entire on palpal tarsus, narrowly divided on tarsus I, widely divided on tarsus II, very widely divided and mixed with setae on tarsus III, absent on tarsus IV. Paired claws on tarsi I–IV with 7–8 teeth on each margin. Palpal claw with 4 promarginal teeth. Leg measurements:

Palp I II III IV Femur 4.14 5.53 5.09 4.35 5.82 Patella 2.36 3.43 2.94 2.52 2.92 Tibia 2.96 4.59 4.20 3.36 5.11 Metatarsus ― 3.67 3.38 4.37 6.82 Tarsus 2.53 2.34 2.28 2.38 2.88 Total 11.99 19.56 17.89 16.98 23.55

Spermathecae ( Figs 6, 7): Receptacle with 2 branches, more proximal branch located at about ⅓ distal part with distinct stalk and globular head; distal branch located at anterior tip of the stalk and composed of 2 globular heads; all heads of about same size, as wide as stalk; receptacles spaced by about length of stalk.

Spinnerets ( Fig. 11): PMS: length 0.48, diameter 0.18. PLS: maximal diameter 0.72; length of basal, medial and apical segments 0.97, 0.63, 0.64; total length 2.24; apical segment triangular. Male. Unknown.

Holotype: ♀ Armenia: Vayot Dzor Province : Gnishik River Canyon , road to Noravank Monastery, 39°41'14"S 45°13'21"E, 1400 m, 10.v.2021, Y.M. Marusik (ZMMU).

Paratype: 1 juv., collected together with the holotype (ZMMU).

Distribution: The species is known only from the type locality ( Fig. 12).

Comments: In the holotype, the PME pair is completely lacking, and the spider is in fact six-eyed, while the paratype juvenile has a normally looking pair of small PME ( Fig. 4 cf. Fig. 5) .

Ecology: The type series was collected in the midland mountain zone, on open clay slope with embedded small stones ( Figs 13–17). That appears to be unusual for Raveniola occurring in the Caucasus (the previously known Caucasian species were collected from more mesophilic biotopes; see Zonstein et al. 2018). Spiders were found dwelling in cavities among stones. This slope was inhabited by small pholcids, belonging to a seemingly new to science species of Spermophora Hentz, 1841 . They also were found dwelling along those cavities.