Chthonius monguzzii, Gardini, Giulio, 2013

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 : 76-79

Chthonius (E.) monguzzii n. sp.

( Figs 155–162 , 291 )

Type locality: Italy, Lombardy, Brescia Prov., Sulzano, Oricina de la Pofa del Giardì 438 Lo/BS (45°40ʹ24ʺN 10°06ʹ43ʺE).

Distribution. Italy: Lombardy, Friuli.

Diagnosis (Ƥ). An anophthalmic hypogean Chthonius (Ephippiochthonius) from 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) at level of the spinneret; both sexes with pointed spinneret; tergite I with 2 setae; pedipalpal hand (in lateral view) without a rounded hump distad of the trichobothria ib-isb, weakly depressed at level of ib-isb; fixed and movable chelal fingers respectively with 14–17 and 8–11 triangular teeth; fixed chelal finger at level of est-it with 3–4 teeth occupying 0.1 mm (distance between successive apices 0.040–0.048 mm); proximal half of movable chelal finger with straight, thick marginal lamina; length of chela 1.15–1.27 (3), 1.24–1.35 (Ƥ), length of movable chelal finger 0.68–0.77 (3), 0.73–0.81 (Ƥ); chela 7.05–7.9 (3), 6.7–7.5 (Ƥ) times as long as deep; ratio of pedipalpal femur/carapace 1.7–2.0 (3Ƥ).

Type material. ITALY— Lombardy: Brescia Prov.— 1 3 (holotype) 1 3 1 Ƥ (paratypes), Sulzano, Oricina (or Uricina) de la Pofa del Giardì 438 Lo/BS (45°40ʹ24ʺN 10°06’43ʺE), 702 m a.s.l., 4.IV.2007, L. Bodei leg. Lombardy: Bergamo Prov.— 1 Ƥ (paratype), Parre, Miniere di Monte Trevasco, 16.III.2003, R. Monguzzi leg. Friuli: Pordenone Prov.— 1 3 1 Ƥ (paratypes), Tramonti di Sotto, Grotta della Foos (= Bus del Fous) 229 Fr/PN, 410 m a.s.l., 10.IV.2002, R. Monguzzi leg. (holotype deposited in MHNG, paratypes in G. Gardini coll., Genoa).

Derivatio nominis. The species is dedicated to Riccardo Monguzzi (Milan), entomologist and biospeleologist, in appreciation of his contributions to our knowledge of the Italian subterranean fauna.

Description of adults (Ƥ). Highly specialized troglomorphic facies; integument without pigmentation; hispid granulation on lateral surfaces of carapace, on cheliceral palm and on chelal hand. Carapace 1.0–1.2 times longer than broad, weakly constricted basally; anterior margin (figs 155–156) without epistome, with small and spaced denticles between median macrosetae; ocular area as in fig. 157, no eyes or eye-spots; standard chaetotaxy 4:6:4:2:2(18), macrosetae fine; number of preocular microsetae not constant: 0+0, 0+1 or 1+ 1 in specimens from Lombardy, 2 microsetae on each side in specimens from Friuli; length of anteromedian macrosetae 0.12–0.14 mm, length of median macrosetae of the median row 0.19 mm. Standard chaetotaxy of tergites I–X 2:4:4:4:6:6:6:6:6:4; tergite II of Ƥ from Parre with 3 setae, of 3 and Ƥ from Tramonti di Sotto respectively with 3 and 2 setae. Chaetotaxy of sternites II–X 8–11:(3)8(3):(2)6–8(2):9–10:8:6–8:6–8:6–8:7; genital opening of males flanked by 6– 9 setae on each side. Chelicerae (figs 158–159) 2.4–2.5 times as long as broad, palm with 6 setae and 3 microsetae laterally; fixed finger with 8–10 teeth proximally reduced in size and 4–10 proximal microtubercles; movable finger with an isolated subapical tooth (di) level with spinneret, 8–10 teeth (distal 5 subequal in size) and 3–5 proximal microtubercles; gl ratio 0.50–0.61; spinneret triangular, prominent, apically pointed, larger in females; rallum with 11 blades; serrulae interior and exterior respectively with 12–14 and 16–17 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3–4 + 3 marginal microsetae, II 4–5, III 6, IV 6 (rarely 5 or 7); coxa II with 6–12 coxal spines, coxa III with 3–4 coxal spines; intercoxal tubercle bisetose (with one microseta in Ƥ from Sulzano). Pedipalp: femur 8.3–9.0 (3), 8.0–8.7 (Ƥ) times as long as broad, with laterobasal hispid granulation; chela (figs 160–162) 7.05–7.9 (3), 6.7–7.5 (Ƥ); hand of chela 2.9 (3), 2.7–2.9 (Ƥ) times as long as deep, weakly depressed at level of ib-isb in males; fixed chelal finger with 14–17 triangular teeth with dental canals: the first 2–3 distal ones small and the first 1–2 proximal ones squat and apically rounded, the other teeth large, sharp and weakly reclined; base of fixed finger with 10–18 microtubercles on the marginal lamina; tip of fixed finger with a modified accessory tooth (td) on antiaxial face; fixed chelal finger at level of est-it with 3–4 teeth occupying 0.1 mm (distance between successive apices 0.040–0.048 mm); distal half of movable finger with 10–11 (rarely 8) upright triangular teeth with dental canals (specimens of Sulzano with a small distal tooth without dental canals) and, proximally to halfway between sb–st, with 1–3 vestigial teeth without dental canals; marginal lamina between b and sb more slender, sometimes with few microtubercles; coupled sensilla pc at level of sb or a little distad or proximad of sb; trichobothria as in figs 161–162, ist very distad of the line eb-esb, at level of b; basal apodeme of movable finger strongly sclerotized, bent and apically truncated; ratio of movable finger/hand of chela 1.4–1.7 (3), 1.5–1.65 (Ƥ); ratio of pedipalpal femur/movable finger 1.2–1.25 (3Ƥ); ratio of pedipalpal femur/ carapace 1.7–2.0 (3Ƥ).

Measurements (in mm). Body length 1.5–1.6 (3Ƥ). Carapace 0.47–0.50 × 0.41–0.45 (0.37–0.41 anteriorly) (3), 0.44–0.53 × 0.43–0.47 (0.38–0.43 anteriorly) (Ƥ). Chelicerae 0.41–0.455 × 0.17–0.185 (3), 0.43–0.48 × 0.18–0.20 (Ƥ); movable finger length 0.22–0.24 (3), 0.22–0.26 (Ƥ). Pedipalp: femur 0.83–0.90 × 0.10 (3), 0.88– 0.96 × 0.11 (Ƥ); chela 1.15–1.27 × 0.16–0.17 (3), 1.24–1.35 × 0.17–0.185 (Ƥ); hand length 0.46–0.49 (3), 0.49– 0.50 (Ƥ); movable finger length 0.68–0.77 (3), 0.73–0.81 (Ƥ).

Remarks. Among the species of the Chthonius fuscimanus group, C. monguzzii n. sp. is related to the hypogean C. pieltaini from Veneto and Lombardy, from which it differs in having only 2 setae on tergite I (4 in C. pieltaini ), the movable cheliceral finger with a spinneret in both sexes and in having the subapical tooth (di) level with the spinneret (males without spinneret and di proximad with respect to the spinneret in C. pieltaini ), the larger size (length of chela 1.15–1.27 (3) 1.24–1.35 (Ƥ) mm in C. monguzzii , 0.75–1.04 (3) 0.93–1.14 (Ƥ) mm in C. pieltaini ), the more slender appendages (chela 7.05–7.9 (3) 6.7–7.5 (Ƥ) times as long as deep, ratio of pedipalpal femur/carapace 1.7–2.0 in C. monguzzii ; 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 in C. pieltaini ) and the different dentition.

Figures

FIGURES 155 – 160. Chthonius (E.) monguzzii n. sp. 155, male holotype, anterior margin of carapace; 156, female paratype (Lombardy, Sulzano), id.; 157, male holotype, anterolateral portion of carapace; 158, id., right chelicera; 159, female paratype (Lombardy, Sulzano), id.; 160, male holotype, tip of fixed chelal finger, dorsal view.

FIGURES 161 – 162. Chthonius (E.) monguzzii n. sp. 161, male holotype, right chela, lateral view; 162, female paratype (Lombardy, Sulzano), id. (Scale bar 0.1 mm).

FIGURES 290 – 293. Distribution maps for the Italian species of the Chthonius fuscimanus group. 290, Chthonius (E.) boldorii Beier, 1934; 291, Chthonius (E.) genuensis Gardini, 1990, C. (E.) gestroi Simon, 1896, C. (E.) monguzzii n. sp., C. (E.) pieltaini Beier, 1930, C. (E.) troglophilus Beier, 1930 and C. (E.) zoiai Gardini, 1990; 292, Chthonius (E.) etruscus n. sp., C. (E.) latellai n. sp., C. (E.) magrinii n. sp. and C. (E.) sulphureus n. sp.; 293, Chthonius (E.) aeneae n. sp., C. (E.) gallii n. sp., C. (E.) intemelius n. sp. and C. (E.) ligur n. sp.