Chthonius
Creators: name: Gardini, Giulio
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Chthonius

description: Chthonius (E.) pieltaini Beier, 1930
(Figs 179–186, 291)
Chthonius (Ephippiochthonius) pieltaini Beier 1930a: 327, fig. 5. Chthonius (E.) pieltaini: Gardini 1991: 178.
Type locality: Italy, Veneto, Vicenza Prov., Longare, Covoli di Costozza 274 V/VI (45°28ʹ22.7ʺN 11°36ʹ0 3.7ʺE).
Distribution. Italy: Veneto, Lombardy.
Diagnosis (Ƥ). An anophthalmic hypogean Chthonius (Ephippiochthonius) from the southeastern 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), in females proximal with respect to the spinneret; movable cheliceral finger of 3 without spinneret; tergite I with 4 setae; chelal hand (in lateral view) without a rounded hump distad of trichobothria ib-isb, with a weak depression proximad of ib-isb; fixed and movable chelal finger respectively with 12–14 and 7–9 triangular teeth; fixed chelal finger at level of est-it with 3–4 teeth occupying 0.1 mm (distance between successive apices 0.030–0.036 mm); proximal half of movable chelal finger with straight, thick marginal lamina; length of chela 0.75–1.04 (3), 0.93–1.14 (Ƥ) mm, length of movable chelal finger 0.44– 0.59 (3), 0.57–0.66 (Ƥ) mm; chela 6.5–7.4 (3), 6.3–6.9 (Ƥ) times as long as deep; ratio of pedipalpal femur/ carapace 1.3–1.7 (3Ƥ).
Material examined. ITALY— Veneto: Belluno Prov.— 1 Ƥ, Lamon, Bus de la Bela, 670 m a.s.l., 23.IV.1984, F. Gasparo leg.; 1 Ƥ, id., Grotta di San Donato 133 V/BL, 644 m a.s.l., 10.VII.1982, F. Gasparo leg. (MCST); 1 3 1 Ƥ, id., 15.IV.1986, E. Piva & I. Ferrari leg. (MSNV); 1 3, Quero, Grotta del Marmo 1202 V /BL, 30.IX.1995, M. Grottolo leg. Veneto: Treviso Prov.— 1 3, Nervesa della Battaglia, Grotta grande di Val Boera 1143 V /TV, 160 m a.s.l., 24.X.2008, D. Bianco & E. Piva leg. Veneto: Vicenza Prov.— 1 3, Alonte, Case Peretto, 75 m a.s.l., 21.V.1994, G. Peretto leg., digging in small valley; 1 3 1 Ƥ, Arcugnano, Grotta della Moreieta 329 V/VI, 375 m a.s.l., 14.VII.1985, E. Piva leg. (MSNV); 2 3, id., 3.IV.2005, D. Bianco & A. Casa leg. (EPV); 1 3, id., Il Longo Bricco 5947 V/VI, 150 m a.s.l., 26.I.2003, E. Piva leg. (EPV); 1 Ƥ, Brendola, Grotta di San Vito 96 V /VI, 71 m a.s.l., 22.VI.1982, E. Piva leg. (MSNV); 1 Ƥ, Cornedo Vicentino, Grotta ai Cocchi 2000 V /VI, 290 m a.s.l., 19.IX.1982, E. Piva leg. (MSNV); 1 Ƥ, Isola Vicentina, Grotta del Convento a quota superiore, 5.II.1986, E. Piva & I. Ferrari leg. (MSNV); 1 Ƥ, id., 8.X.1989, S. Zoia leg.; 1 Ƥ, Longare, Grotta del Tesoro 166 V/VI, 17.X.1982, E. Piva leg.; 1 Ƥ, Valdagno, Grotta dei Partigiani 1783 V /VI, 475 m a.s.l., 12.VIII.2004, D. Bianco leg. (EPV); 1 Ƥ, Zovencedo, Grotta dei due cani 1318 V /VI, 360 m a.s.l., 13.III.1997, R. Monguzzi leg. (RMM); 1 Ƥ 4T, id., 6.IV.2008, E. Piva leg.; 1 Ƥ, id., 19.X.2008, E. Piva leg.; 3 3 7 Ƥ 1T, id., 19.IV.2009, E. Piva leg. Veneto: Verona Prov.— 1 Ƥ, Ponte di Veja, Grotta A, 5.IV.1978, G. Caoduro leg. (MSNV); 1 3, Roverè Veronese, Loneri, Buso del Gatto 1421 V /VR, 22.V.1988, G. Comotti & A. Baldan leg.; 1 3, Sant’Ambrogio di Valpolicella, Cava n. 5, 18.IV.1999, E. Piva leg.; 1 Ƥ, id., Cava n. 3, 600 m a.s.l., 21.XI.1999, E. Piva leg.; 1 3, Sant’Anna d’Alfaedo, Grotta Lorenzo Bertola 1120 V /VR, 600 m a.s.l., 2.IX.2007, E. Piva leg. (EPV); 1 Ƥ, Tregnago, Grotta dei Damati 9 V /VR, 17.VI.2006, M. Grottolo leg. Lombardy: Bergamo Prov.— 1 Ƥ, Grone, Colle San Fermo, 1100 m a.s.l., 4.IV.1996, R. Monguzzi leg.
Description of adults (Ƥ). Troglomorphic facies, integument depigmented; lateral surfaces of carapace, cheliceral palm and distal surface of chelal hand with strong hispid granulation. Carapace 0.9–1.1 times longer than broad, subquadrate, slightly constricted posteriorly; anterior margin (figs 179–180) strongly dentate between median macrosetae, without epistome, sometimes weakly prominent in females; no eyes or eye-spots, ocular area as in fig. 181; chaetotaxy mm 4mm:6:4:2:2(18), macrosetae fine (thicker and more abruptly acuminate in specimens from Lamon), rarely 3 or 4 preocular microsetae on each side; length of anteromedian macrosetae 0.13– 0.16 mm. Chaetotaxy of tergites I–X 4:4:4:4:6:6:6:6:6:4. Chaetotaxy of sternites II–X 9:(3)8(3):(2)8(2):8–10:8:6– 8:6:6:7; genital opening of males flanked by 6–7 setae on each side. Chelicerae (figs 183–183) 2.2–2.4 times as long as broad, palm with 6 setae and 2 (rarely 3) microsetae laterally; fixed finger with 7–10 teeth, proximally reduced in size, and 6–8 proximal microtubercles; movable finger with a large isolated subapical tooth (di), proximal with respect to spinneret in females, 5–8 contiguous teeth and 3–4 proximal microtubercles; gl ratio 0.50– 0.57; spinneret almost absent in males, prominent, cone-shaped and apically rounded in females; rallum with 11 blades; serrulae interior and exterior respectively with 12–13 and 14–15 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 4 +3 marginal microsetae, II 4 (rarely 5), III 5 (rarely 6), IV 6; coxa II with 7–12 coxal spines, coxa III with 3–6 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 6.35–7.5 (3), 6.9–7.3 (Ƥ) times as long as broad; chela (figs 184–186) 6.5–7.4 (3), 6.3–6.9 (Ƥ) times as long as deep; hand of chela 2.6–2.85 (3), 2.5–2.75 (Ƥ) times as long as deep, clearly depressed at level of ib-isb in males; fixed chelal finger with 12–14 large triangular teeth, with dental canals: the first proximal tooth (rarely the first two proximal teeth) squat and apically rounded, other teeth pointed and weakly reclined; base of fixed finger with 10–14 microtubercles; tip of fixed 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 0.030–0.036 mm); distal half of movable finger with 7–9 large, upright, triangular teeth with dental canals and proximally to halfway between sb and st, with 1–4 vestigial teeth, without dental canals; marginal lamina between b and sb finer and with 4–10 microtubercles; coupled sensilla pc halfway between b and sb, rarely nearer to sb; trichobothria as in figs 185–186, ist mostly distad of line eb-esb; basal apodeme of movable finger strongly sclerotized, fine, bent and apically crenate; ratio of movable finger/hand of chela 1.45–1.5 (3), 1.4–1.6 (Ƥ); ratio of pedipalpal femur/movable finger 1.15–1.3 (3Ƥ); ratio of pedipalpal femur/carapace 1.3–1.7 (3Ƥ).
Measurements (in mm). Body length 1.3–1.45 (3), 1.4–1.8 (Ƥ). Carapace 0.41–0.45 × 0.36–0.43 (0.32–0.40 anteriorly) (3), 0.42–0.51 × 0.42–0.52 (0.37–0.48 anteriorly) (Ƥ). Chelicerae 0.31–0.41 × 0.14–0.17 (3), 0.39– 0.47 × 0.17–0.20 (Ƥ), movable finger length 0.16–0.21 (3), 0.20–0.24 (Ƥ). Pedipalp: femur 0.54–0.75 × 0.085– 0.10 (3), 0.66–0.84 × 0.095–0.115 (Ƥ); chela 0.75–1.04 × 0.115–0.15 (3), 0.93–1.14 × 0.14–0.19 (Ƥ); hand length 0.30–0.40 (3), 0.36–0.47 (Ƥ); movable finger length 0.44–0.59 (3), 0.57–0.67 (Ƥ).
Description of tritonymph. Integument depigmented, hispid granulation less marked than in adults. Carapace 1.0 times longer than broad, anterior margin as in adults; no eyes or eye-spots; chaetotaxy m 4m:6:4:2:2(18); length of anteromedian macrosetae 0.115 mm. Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II–X 5:(2)6(2):(1)6(1):8:7:6:6:6:7. Chelicerae 2.2 times as long as broad, palm with 5 setae and 1 lateral microseta; fixed finger with 7 teeth and few proximal microtubercles, movable finger with 6 teeth and an isolated subapical tooth (di) proximal with respect to spinneret; gl ratio 0.52. Pedipalp: femur 5.9 times as long as broad; chela 6.3 times as long as deep; hand of chela 2.6 times as long as deep, clearly depressed at level of trichobothrium ib; fixed finger with 12 large, triangular teeth and trace of one proximal tooth; base of fixed finger with 10 microtubercles; tip of fixed finger with a modified accessory tooth (td) on antiaxial face; distal half of movable chelal finger with 7 triangular pointed teeth and 2 proximal vestigial teeth; base of movable finger with a few microtubercles; coupled sensilla pc just distad of trichobothrium b; ratio of movable finger/hand of chela 1.45; ratio of pedipalpal femur/ movable finger 1.2; ratio of pedipalpal femur/carapace 1.4.
Measurements (in mm). Body length 1.2. Carapace 0.37 × 0.36 (0.33 anteriorly). Chelicerae 0.33 × 0.15, movable finger length 0.17. Pedipalp: femur 0.53 × 0.09; chela 0.76 × 0.12; hand length 0.31; movable finger length 0.45.
Remarks. Chthonius pieltaini is a subterranean species, with a high degree of troglomorphy, known from the Dolomites to the Bergamasque pre-Alps westwards. Among the species of the C. fuscimanus group, with an isolated subapical tooth (di) on the movable cheliceral finger, C. pieltaini is probably related to the epigean C. nanus, widespread in the same geographical area, because of the shape of chelal hand and the form of the dentition. They clearly differ from each other in most troglomorphic characters and in the shape of the male spinneret. The epigean C. fuscimanus also partially occupies the same area (East of Lake Garda), but its relationship with C. pieltaini is doubtful. Both species are similar in size (length of pedipalpal chela 0.75–1.04 (3) 0.93–1.14 (Ƥ) mm in C. pieltaini, 1.0–1.12 (3) 0.85–1.25 (Ƥ) mm in C. fuscimanus) and show an identical ratio of pedipalpal femur/ carapace (1.3–1.7 in both species): since hypogean species usually show, with respect to the related epigean species, remarkable troglomorphy such as greater size and slender appendages, I suppose that C. fuscimanus is not related to C. pieltaini.
Among the species of the Chthonius fuscimanus group with troglomorphic facies, C. pieltaini is related to the hypogean C. monguzzii from Carnic Alps to Bergamasque pre-Alps westwards (see Remarks under latter for comparison).
description: Published as part of Gardini, Giulio, 2013, A revision of the species of the pseudoscorpion subgenus Chthonius (Ephippiochthonius) (Arachnida, Pseudoscorpiones, Chthoniidae) from Italy and neighbouring areas, pp. 1-151 in Zootaxa 3655 (1) on pages 93-97, DOI: 10.11646/zootaxa.3655.1.1, http://zenodo.org/record/223358