Troglohyphantes vignai Brignoli, 1971

Isaia, Marco & Pantini, Paolo, 2010, New data on the spider genus Troglohyphantes (Araneae, Linyphiidae) in the Italian Alps, with the description of a new species and a new synonymy, Zootaxa 2690, pp. 1-18 : 11

Troglohyphantes vignai Brignoli, 1971

Figures 15–18

Troglohyphantes vignai Brignoli, 1971 : Brignoli, 1971d: 170, f. 52–58., Pesarini, 2001b: 116; Isaia et al. (2010). Troglohyphantes rupicapra Brignoli, 1971 : Brignoli, 1971d: 172, f. 59–60; Brignoli, 1979l: 321, f. 13–14; Pesarini, 1988c: 238, f. 3.

Material examined. Italy, Piemonte, Province of Cuneo: Garessio, Voragine della Ciuaiera cave (146 Pi/CN), 09/09/2001, 1 ɗ, 2 Ψ, S. Bugalla, M. Chiamenti and T. Pascutto legerunt (CI); 12/10/2008, 3 ɗ, 4 Ψ, E. Lana legit (CI); Casteldelfino, Pertus dal Drai cave (1017 Pi/CN), 25/08/2001, 1 ɗ, 6 Ψ, E. Lana legit (CI); Sampeyre, Buco del Nebin 1 cave (1158 Pi/CN), 17/11/2008, 1 Ψ, E. Lana legit (CI); Briga Alta, Abisso Vento (3500 Pi/CN), 30/06/2001, 1 ɗ, 1 Ψ, S. Bugalla and T. Pascutto legerunt (CI); Province of Torino, Roure, Val Chisone, Tana del Diavolo cave (1591 Pi/TO), 11/11/2006, 3 ɗ, M. Isaia legit (CI); Perrero, Tuna dal Diau cave (1621 Pi/TO), 23/10/2006, 1 ɗ, M. Isaia and E. Lana legerunt (CI).

Note. Specimens collected in the caves of the high Pesio Valley, including type locality of T. rupicapra Brignoli, 1971 (= T. vignai Brignoli, 1971 after Pesarini, 2001), exhibit higher degree of troglomorphism (higher depigmentation, reduction of PLE and PME, lowering of the profile of cephalothorax; Figures 15–18 ) in respect to the northern populations of the same species. Deeleman-Reinhnold (1978) underlines that the troglomorphism in Troglohyphantes species (i.e. loss of pigmentation, reduction of the eyes apparatus, thinning of the integuments, richer spinulation) is directly related to regressive evolutionary phenomena. The same author also points out that the degree of eye reduction within the same population is “astonishingly uniform” and that “the reduction of the optical apparatus keeps pace with the rise of isolating mechanism” ( Deeleman-Reinhold, 1978). Accordingly, we assume an incipient phenomenon of speciation for these populations, previously considered by Brignoli (1971) as separate species.

Figures

FIGURES 15 – 18. Troglohyphantes vignai Brignoli, 1971. 15 – 16. Male from Tana del Diavolo cave (1591 Pi / TO), Chisone Valley, Roreto Chisone, Province of Torino (19 / 09 / 2007, M. Isaia legit). 17 – 18. Male from Abisso Rangipur (761 Pi / CN), High Pesio Valley, Conca delle Carsene, Province of Cuneo (14 / 10 / 2001, E. Lana legit). 15, 17. Prosoma and chelicerae, frontal view. 16, 18. Prosoma, lateral view. Scale 15 – 18: 0.5 mm. Illustration by Elena Pelizzoli.