Chthonius

Gardini, Giulio, 2013, A revision of the species of the pseudoscorpion subgenus Chthonius (Ephippiochthonius) (Arachnida, Pseudoscorpiones, Chthoniidae) from Italy and neighbouring areas, Zootaxa 3655 (1), pp. 1-151: 126-130

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http://dx.doi.org/10.11646/zootaxa.3655.1.1

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Chthonius
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Chthonius   (E.) troglophilus   Beier, 1930

( Figs 242–251 View FIGURES 242 – 248 View FIGURES 249 – 251 , 291 View FIGURES 290 – 293 )

Chthonius (Ephippiochthonius) troglophilus Beier 1930 b: 73   .

Chthonius   (E.) troglophilus   : Beier 1932: 58, fig. 72; Gardini 1990: 236, figs 9–16. Chthonius   (E.) cavicola   Gardini 1990: 240, figs 17–21 (n. syn.).

Type locality: Italy, Liguria, Savona Prov., Castelbianco, Tana do Scovero 86 Li/SV (44 °06ʹ 55 ʺN 8 °03ʹ 40 ʺE).

Distribution. Italy: Piedmont, Liguria.

Diagnosis (Ƥ). An anophthalmic hypogean (rarely endogean) Chthonius   ( Ephippiochthonius   ) from southwestern Alps that differs from other species of the C. fuscimanus   group in the following combination of characters: movable cheliceral finger with isolated subapical tooth (di) and subequal teeth; male with low spinneret; chelal hand (in lateral view) without a rounded hump distad of trichobothria ib-isb, weakly depressed behind ib-isb; fixed and movable chelal finger respectively with 13–17 and 8–11 triangular teeth, fixed finger at level of est-it with 3-4 teeth occupying 0.1 mm (distance between successive apices 0.027–0.031 mm); proximal half of movable chelal finger with straight, thick marginal lamina; length of chela 1.0– 1.29 (3), 0.77–1.39 (Ƥ) mm, length of movable chelal finger 0.60–0.745 (3), 0.455–0.80 (Ƥ) mm; chela 6.7–7.6 (3), 5.45–6.9 (Ƥ) times as long as deep; ratio of pedipalpal femur/carapace 1.6–1.85 (3), 1.3–1.7 (Ƥ).

Type material examined. ITALY — Liguria: Imperia Prov.— 1 Ƥ (holotype, Chthonius   (E.) cavicola   Gardini, 1990), Pigna, Buggio, Grotta dei Rugli 19 Li/IM, 740 m a.s.l., 6.IX. 1978, E. Gardini, G. Gardini & S. Zoia leg.

Other material examined. ITALY— Piedmont: Cuneo Prov. – 1 Ƥ, Borgo San Dalmazzo, Monserrato, Baus d’la Magna Catlina 1059, 1.VII. 2010, M. Isaia leg.; 1 Ƥ, id., 10.VI. 2010 / 10.VI. 2011; 1 3, Eca, Arma dei Grai 120 Pi/CN, 25.VIII. 1968, A. Vigna leg. Liguria: Imperia Prov. – 1 Ƥ, Rocchetta Nervina, Grotta degli Strassasacchi 1176 Li/IM, 560 m a.s.l., 26.I. 2003, S. Zoia & F. Polese leg. Liguria: Savona Prov.— 2 3, Castelbianco, Tana do Scovero 86 Li/SV, 460 m a.s.l., 24.IV. 1986, G. Gardini & R. Rizzerio leg.; 2 3 1 Ƥ, Ceriale, Grotta sopra la Cava 312 Li/SV, 8.X. 1985, G. Gardini & R. Rizzerio leg.; 1 T, id., 4.II. 1986; 1 3 1 Ƥ, id., 8.III. 1986, R. Rizzerio & S.

Zoia leg.; 1 3 2 Ƥ 1 T, id., 23.X. 1986, G. Gardini & R. Rizzerio le.; 1 3 2 Ƥ “ Chthonius Gestroi E. Sim.   (pullus)”, “Gr. Verzi, 16.IV. 1897, A. Dodero leg.” [Loano, Grotta di Verzi 91 Li/SV, 160 m a.s.l.] (MSNG); 1 Ƥ “ Chthonius Gestroi E. Simon   ”, “Gr. Verzi., 28.IV. 1897, R. Gestro leg.” [id.] (MSNG); 1 Ƥ “ Chthonius Gestroi E. Simon   ”, “Gr. Verzi, 30 Apr 1898, A. Dodero leg.” [id.] (MSNG); 1 3 1 Ƥ, “Gr. Verzi, 27.V. 1900, A. Dodero leg.” [id.] (MSNG); 1 Ƥ, “ Chthonius Gestroi E. Simon   ” “Gr. Verzi, Apr. 1901, A. Dodero leg.” [id.] (MSNG); 1 3, Loano, Grotta di Verzi 91 Li/SV, 160 m a.s.l., 17.II. 1985, G. Gardini leg.; 1 Ƥ, id., Grotta di Verzi 91 Li/SV, 160 m a.s.l., 31.X. 1985, G. Gardini & R. Rizzerio leg.; 1 T, Magliolo, Tana dell’Ermellino 767 Li/SV, 21.X. 1973, L. Briganti & G. Gardini leg.; 1 Ƥ (M. Beier det.), Magliolo, Tana del Pecetto 569 Li/SV, 30.IX. 1973, G. Gardini leg.; 5 Ƥ, id., 25.I. 1976, R. Poggi & S. Zoia leg.; 1 Ƥ, id., 18.V. 1981, D. Bruzzone, G. Gardini & G. Troiano leg.; 1 3, id., 25.IV. 1985, G. Gardini leg.; 1 3 3 Ƥ 1 T, id., 23.X. 1985, G. Gardini & R. Rizzerio leg.; 1 Ƥ, id., 28.V. 1986, G. Gardini & R. Rizzerio leg.; 1 Ƥ, Vendone, N slope Monte Castell’Ermo, 16.V. 1976, G. Gardini leg. under stone; 3 3 1 Ƥ 1 T, Vendone, Abisso di Montenero 306 Li/SV, 23.XI 1980, G. M. Schiaffino, A. Torchia & S. Zoia leg.

Description of adults (Ƥ). Troglomorphic facies. Integument depigmented; hispid granulation on lateral surfaces of carapace and on cheliceral palm. Carapace 1.0– 1.1 times longer than broad, slightly constricted posteriorly; anterior margin (fig. 242–243) between median macrosetae with sharp denticles, more prominent and strongly dentate in female, but always without epistome; no eyes or eye-spots (fig. 244); chaetotaxy mm 4mm: 6: 4: 2: 2 (18), macrosetae thin; rarely 1 preocular microseta on one side; median row rarely with 6 macrosetae (Ƥ from Pigna: Grotta dei Rugli); length of anteromedian macrosetae 0.11–0.13 mm. Chaetotaxy of tergites I –X 4: 4: 4: 4: 6: 6: 6: 6: 6: 4. Chaetotaxy of sternites II –X 10:(3) 7–10 (3):(2) 7–8 (2): 8–9: 6–7: 6: 6: 6: 7; genital opening of males flanked by 5–7 setae on each side. Chelicerae (figs 245–247) 2.05–2.55 times as long as broad, palm with 6 (rarely 5) setae and 2 or 3 microsetae laterally; fixed finger with 8–12 teeth proximally reduced in size and few proximal microtubercles; movable finger with 6–10 teeth and an isolated subapical tooth (di), in females a little proximal with respect to the spinneret; gl ratio 0.53–0.57; spinneret almost absent in males, prominent and apically rounded in females; rallum with 11 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 8–13 coxal spines, coxa III with 3–8 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 7.2–8.6 (3), 6.1–8.2 (Ƥ) times as long as broad; chela (figs 248–251) 6.7–7.6 (3), 5.45–6.9 (Ƥ) times as long as deep; hand of chela 2.7–3.1 (3), 2.3–2.9 (Ƥ) times as long as deep, weakly depressed proximally trichobothria ib-isb; fixed chelal finger with 13–17 triangular, large and pointed teeth but the proximal one, rounded, all teeth with dental canals; base of fixed finger with 8–11 microtubercles; tip of fixed chelal finger with a modified accessory tooth (td) on antiaxial face; fixed chelal finger at level of est-it with 3 (rarely 4) teeth occupying 0.1 mm (distance between successive apices 0.027–0.031 mm); distal half of movable chelal finger with 8–11 triangular, upright, pointed teeth—the proximal one sometimes reduced and rounded—all with dental canals; marginal lamina, distad of sb, thick and mostly straight, rarely irregularly undulated; coupled sensilla pc variable in position between sb and halfway between b and sb; trichobothria as in figs 249–251; basal apodeme of movable chelal finger strongly sclerotized, rectangular and thin; trichobothria eb-esb-ist mostly placed in a straight line, rarely ist proximad of line eb-esb; ratio of movable finger/hand of chela 1.3–1.55 (3 Ƥ); ratio of pedipalpal femur/movable finger 1.2–1.3 (3 Ƥ); ratio of pedipalpal femur/carapace 1.6–1.85 (3), 1.3–1.7 (Ƥ).

Measurements (in mm). Body length 1.45–1.78 (3) 1.4–1.95 (Ƥ). Carapace 0.45–0.54 × 0.43–0.50 (3), 0.41– 0.60 × 0.38–0.55 (Ƥ). Chelicerae 0.41–0.51 × 0.18–0.20 (3), 0.35–0.55 × 0.16–0.235 (Ƥ), movable finger length 0.20–0.26 (3), 0.175–0.27 (Ƥ). Pedipalp: femur 0.72–0.95 × 0.10–0.11 (3), 0.55–1.02 × 0.09–0.125 (Ƥ); chela 1.0– 1.29 × 0.15–0.17 (3), 0.77–1.39 × 0.13–0.21 (Ƥ); hand length 0.41–0.52 (3), 0.31–0.57 (Ƥ); movable finger length 0.60–0.745 (3), 0.455–0.80 (Ƥ).

Description of tritonymph. Integument depigmented, hispid granulation less marked than in adults. Carapace 1.1 times longer than broad, no eyes or eye-spots, no epistome; chaetotaxy m 4m: 6: 4: 2: 2 (18). Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II –X 5:(2) 8 (2):(1) 6 (1): 7: 6: 6: 6: 6: 7. Cheliceral palm with 5 setae and 2 microsetae laterally; spinneret prominent as in females. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 2 marginal microsetae, II 4, III 5, IV 5; intercoxal tubercle bisetose. Pedipalp: femur 6.2–6.65 times as long as broad; chela (see Gardini 1990, fig. 16) 6.3 times as long as deep; hand of chela 2.6–2.7 times as long as deep; fixed finger with 14 large, triangular teeth and 7–8 proximal microtubercles; tip of fixed chelal finger with a modified accessory tooth (td) on antiaxial face; movable chelal finger with 8 triangular teeth; coupled sensilla pc a little distad of b; ratio of movable finger/hand of chela 1.36–1.41; ratio of pedipalpal femur/movable finger 1.2– 1.25.

Measurements (in mm). Body length 1.4. Pedipalp: femur 0.59–0.665 × 0.095–0.10; chela 0.85–0.91 × 0.135– 0.145; hand length 0.36–0.375; movable finger length 0.49–0.53.

Remarks. Chthonius troglophilus   was redescribed from type material and further specimens from the Ligurian Alps and pre-Alps by Gardini (1990). In the same paper he described the hypogean species C. cavicola   , from the same geographical area, based on a single female showing the carapace with 6 macrosetae on the median row (as opposed to 4, the normal number in all species of the C. fuscimanus   group) and dimensions a little smaller than those of C. troglophilus   . Examination of further material from Imperia Province and Piedmont, together with an endogean specimen (the smallest of all) from Vendone (Savona Prov.) extends the dimensional limits of C. troglophilus   and leads me to suppose that the unusual chaetotaxy of carapace in holotype of C. cavicola   is a chance variation (the female from the near Grotta degli Strassasacchi, Rocchetta Nervina, shows the standard chaetotaxy 4: 6: 4: 2: 2). The following synonymy is therefore proposed: Chthonius   (E.) cavicola   Gardini, 1990 is a junior subjective synonym of Chthonius   (E.) troglophilus   Beier, 1930 (n. syn.).

Among the species of the Chthonius fuscimanus   group, C. troglophilus   is related to the epigean C. nanus   , a widespread species in the same geographical area, from which it evidently differs in troglomorphic characters. C. troglophilus   is closely related to the hypogean C. gestroi   from western Liguria (Finalese), from which it differs in the more moderate troglomorphic facies. For a comparison between the two species, see Remarks under C. gestroi   .