Bioacoustics of Piniphantes agnellus

DESCRIPTION OF THE MALE (Specimen from Valdieri, Galleria Valscura): overall size and leg length small. Prosoma 0.49 long, 0.40 wide, light-yellowish. Thoracic region yellowish with grey shades. Cephalic region not elevated with a few bristles interspersed among the eyes. Clypeus 0.04 long, slightly indented under the eyes, then convex, with one bristle just below the head region. Eyes normally developed, with pigment and black margins. AME smallest. PLE, PME and ALE almost equal in diameter. ALE and PLE contiguous. PLE–PME distance: 0.011, ALE–AME distance: 0.012, PME–PME distance: 0.013. Eye diameters: AME: 0.015, PME: 0.020, ALE: 0.021, PLE: 0.210. Sternum heart-shaped, yellowish with blackish shades. Chelicerae 0.10 long, light brownish, with 18-20 lateral stridulatory ridges and armed with four contiguous posterior teeth grouped close to the base of the fang (the distal bigger) and three anterior teeth, equally distributed along the cheliceral margin, the median bigger. Legs uniformly light yellowish. Leg I: femur 0.56, other articles missing; leg II: femur 0.39, patella 0.09, tibia‰.65, metatarsus‰.42, tarsus‰.36, TLL 1.91; leg III: femur 1.84, patella 0.11, other articles missing; leg IV: femur 0.48, patella 0.12, other articles missing. Abdomen 0.54 long, 0.38 wide; light-brownish, darker than the prosoma. Palp ( Fig. 6 ): femur 0.12, patella 0.04, tibia 0.03, cymbium 0.12. Cymbium faintly convex, roughly rectangular when seen from above, ending proximally with a straight border, perpendicular to the main axis ( Fig. 6B ). Paracymbium U-shaped in lateral view, bearing some hairs on the proximal part, apical part gradually narrowed anteriorly ( Figs 6A , 7D ). Distal suprategular apophysis directed upwards, with a sharp end ( Fig. 7C ). Proximal part of the embolus with elongated projection bearing numerous finger-like protrusions ( Fig. 7A ). Embolus sickle shaped, thumb well-developed. Embolus proper bifid ( Fig. 7A ). Lamella characteristica duck-head shaped with an upper sclerotized horizontal branch and a lower one, smaller and less sclerotized ( Fig. 7B ). SPINATION (BASED ON ALL MALES EXAMINED) Femur I with one prolateral spine; femur II, III and IV with no spines. Patella I-IV with one dorsal spine. Tibia I with two dorsal, one prolateral, and one retrolateral spines; tibia II with one dorsal, and one prolateral and one retrolateral spines; tibia III and IV with one dorsal and one retrolateral spines. Metatarsus I–IV with one dorsal spine. Position of TmI: 0.19. Trichobothrium on Mt IV absent. ECOLOGY AND DISTRIBUTION Specimens of P. agnellus n. comb. have been collected primarily in talus caves and rocky areas at medium-high altitudes, between 1900 and 2600 m a.s.l. Mammola et al. (2018) consider the species as a troglophile elements. The distribution of the species is centred on the Alpine districts of Maritime Alps and Ligurian Alps. However, the record of one male in Champlas Janvier (Cottian Alps) let envisage a wider distribution, extending north.

TAXONOMICAL REMARKS In the original description, Maurer & Thaler (1988) assigned the newly described species to the genus Lepthyphantes Menge, 1866 . In lack of males, the diagnosis – and presumably the genus assignation – was based on the morphology of the epigyne, bearing some characteristic lateral extensions at the base of the proscape. The occurrence of males of a possible undescribed species together with females of former Lephtyphantes agnellus at two sites (Galleria Valscura, Valdieri, Maritime Alps and Monte Grai, Triora, Ligurian Alps) allowed to pair males and females. Moreover, the match was confirmed by morphological characters shared by males and females, such as chaetotaxy, cheliceral teeth, stridulatory ridges, abdominal pattern and ocular pattern. Some years after the description of L. agnellus , Saaristo & Tanasevitch (1993 , 1996 ) reclassified the genus Lepthyphantes using a typological approach, examining the morphology of the genital organs, especially males. As a result, most of the European Lepthyphantes species were transferred or assigned to new genera. On the other hand, given the lack of males, L. agnellus was not transferred to any of the newly created genera. Our finding of the unknown male now allows the placement of this species within the genus Piniphantes Saaristo & Tanasevitch, 1996 . According to the original description, the genus Piniphantes includes small Linyphiids, having in males an elongated projection at the proximal part of the embolus bearing numerous finger-like protrusion ( Saaristo & Tanasevitch 1996 ). Such character is particularly remarkable in our case ( Fig. 7A ). Moreover, other details given in the genus description ( Saaristo & Tanasevitch 1996 ) match our case, such as chaetotaxy and lack of abdominal pattern. The species is then assigned to the genus Piniphantes , with representatives in the area of Tian Shian Mountains (Central Asia) (5 species : P. cinereus (Tanasevitch, 1986) , P. macer (Tanasevitch, 1986) , P. plumatus (Tanasevitch, 1986) , P. uzbekistanicus (Tanasevitch, 1983) , P.zonsteini (Tanasevitch, 1989)) , Himalaya (one species , P. himalayensis (Tanasevitch, 1987)) , Centro-Asiatic-European region (one species , P.pinicola (Simon, 1884)) and Corsica (one species , P. cirratus (Thaler, 1986)) . According to the morphology of the male genitalia, P. agnellus n. comb. is similar to P. cirratus , for which the only holotype male is known, preventing any comparison of the female.