Amaurobius caucasicus, Marusik & Otto & Japoshvili, 2020

Marusik, Yuri M., Otto, S. & Japoshvili, G., 2020, Taxonomic notes on Amaurobius (Araneae: Amaurobiidae), including the description of a new species, Zootaxa 4718 (1), pp. 47-56 : 48-49

Amaurobius caucasicus sp. n.

Figs 3–4, 7–8 , 15

Types: Holotype ♂, GEORGIA, Kakheti Region, Lagodekhi Reserve , 41.87147°N, 46.31153°E, 1351m, intermediate mixed montane forest with dominant beech, malaise trap, 12–23.IV.2014, leg. Japoshvili & Kirkitadze, deposited in the Museum für Naturkunde Berlin under the acronym ZMB / Arach 49131 (ex coll. Otto KVS 452/N37) . Paratypes. 1 ♂, same location, 23.IV.–3.V.2014, ZMB / Arach 49132 (ex coll. Otto KBS 258/N38) ; 1 ♂, same location, 5– 15.V.2014, Entomological Collection of the Manchester Museum, MMUE G7628.1 (ex coll. Otto KBS 259/N39) .

Etymology: The name is derived from the Caucasus Major, where the specimens have been found. See also comments below.

Diagnosis. The new species differs from A. antipovae Marusik et Kovblyuk, 2004 , the only other species described from the Caucasus, by having a gradually tapering dorsal tibial apophysis (vs. widened in the terminal 2/3), an intermediate apophysis shorter than the retrolateral one (vs. subequal), presence of a baso-ventral projection of the tegulum (vs. lacking) ( Figs 8 & 13). Amaurobius caucasicus sp. n. clearly differs from A. hercegovinensis by having a thinner retrolateral apophysis, a triangle shaped tegulum in lateral view with a baso-ventral projection (Bp) (vs. rounded tegulum lacking projection), and a tegular apophysis longer than wide (vs. as wide as long).

Description. Male. Body length 6.00±0.65. Carapace 3.13±0.41 long, 2.20±0.16 wide. Abdomen 2.62±0.28 long. Carapace clay colored, cephalic region with hue of black (in one specimen very dark), especially on the sides and black hue extending towards the fovea; thoracic region brighter, with 3 pairs of darker radial marks towards the bright fringe ( Fig. 15 ); clypeus thin (approx. 1.1–1.3 of AME diameter); labium and gnathocoxae light brown to brown, darker than coxae and sternum, distal fringes white. Sternum yellow, towards the sides darker brownish. Chelicerae dark brown; anterior row with 4 teeth; second proximal tooth largest, posterior row with 3 teeth. Palp: femur yellow, patella, tibia and cymbium yellow with darkened bases of apophyses and cymbium, leg coxae yellow. Legs yellow to light brown, distal segments somewhat darker; femur, tibia and metatarsus of all legs with 3 more or less visible darker rings, variable leg spination and segment lengths given in Tabs 1–2 . Leg I 3.7–3.9 times longer than carapace. Abdomen dark gray to black, heart region gray with 2 pairs of lateral black spots or broad black fringe and surrounded by a pale area, posterior half with rows of transversal and posteriorly smaller marks, venter pale, with three longitudinal dark bands, median band thinner than lateral bands, spinnerets pale to clay colored; cribellum reduced.

Palp as in Figs. 3–4, 7–8 . Cymbium length 1.05±0.11; tibia with 5 apophyses: dorsal apophysis (Da) long (as long as tibia), tapering, with a sharp tip, directed antero-prolateraly ( Fig. 4 ); retrolateral apophysis (Ra) straight, with rounded and somewhat widened tip, ca. 2/3 of tibia length (in lateral view) and about 3 times longer than stem width 2.9–3.3 times the width of the stem part ( Fig. 8 ); intermediate apophysis (Ia) located between Da and Ra, digitiform and somewhat longer than half the length of Ra ( Fig. 4 ); ventral apophysis (Va) short wider than long, with claw-like tip directed dorsally (lateral view), cymbium with a distinct fold (Cf) shaped like a three-sided pyramid (tetrahedron). Tegulum triangle-shaped in lateral view, with baso-ventral process (Bp); sperm duct straight in lateral view; tegular apophysis (Ta) longer than wide; tegulum with anterior process, and a spine is absent. Conductor bifurcate near the tip.

Female unknown.

Distribution. The new species is known from the type locality only.

Comments: Among the spiders collected by D.E. Charitonov in the Lagodekhi Reserve, and stored in Janashia Museum (Tbilisi), there is a poorly preserved specimen labelled “ A. caucasicus ” and collection information: “ 25. VI.38, Lagodekhi, Giromsk”, which is very probably conspecific with our specimens (S. Otto, personal observation). Unfortunately, we were not able to obtain these specimens for further study. The here described species was mentioned in Otto & Japoshvili (2018) as Amaurobius sp.

Figures

FIGURES 1–12. Copulatory organs of A. hercegovinensis (1–2, 5–6, 9–12) and A. caucasicus sp. n. (3–4, 7–8). 1, 3—right male palp, ventral; 2, 4—ibid., dorsal; 5, 7—ibid., prolateral; 6, 8—ibid, retrolateral; 9, 11—epigyne, ventral; 10, 12—ibid., dorsal. Figs 9–10 and 11–12 belong to the same paralectotypes.

FIGURES 13–15. Right male palp of Amaurobius antipovae (13) and male habitus of A. antipovae (14) and A. caucasicus sp. n. (15). 14—shows considerable variation of size in specimens collected on the same spot.