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 : 108-110

[ Chthonius (E.) siscoensis Heurtault, 1975 ]

( Figs 205–209 )

Chthonius (E.) siscoensis Heurtault 1975: 313 , figs 1–6. Chthonius (E.) siscoensis : Mahnert 1978: 381, fig. 1.

Type locality: France, Corsica, Dept. Haute-Corse, Sisco, Grotte de Sisco 2C (42°48ʹN 9°26ʹE).

Distribution. France: Corsica.

Diagnosis (Ƥ). A microphthalmic endogean Chthonius (Ephippiochthonius) from Corsica that differs from other species of the C. fuscimanus group in the following combination of characters: movable cheliceral finger without isolated subapical tooth (di); fixed chelal finger with 13–15 triangular teeth, at level of est-it with 2–3 teeth occupying 0.1 mm (distance between successive apices 0.038–0.043 mm); length of chela 1.03–1.21 (3), 1.24 (Ƥ) mm, length of movable chelal finger 0.61–0.70 (3), 0.70 (Ƥ) mm; chela 6.6–6.7 (3), 5.5 (Ƥ) times as long as deep; ratio of pedipalpal femur/carapace 1.7–1.75 (3Ƥ).

Material examined. FRANCE— Corsica: 1 3, Bastia, Brando, Grotta di Brando, 22.V.1982, S. Zoia & A. Torchia leg.

Description of adults (Ƥ). Weak troglomorphic facies. Integument depigmented; hispid granulation on lateral surfaces of carapace, on cheliceral palm, on distal surface of chelal hand and on base of movable chelal finger. Carapace 1.0–1.1 times longer than broad, posteriorly constricted; anterior margin (fig. 205) closely denticulate between median macrosetae, weakly produced as a small epistome in male; anterior eyes reduced to ocular spots, posterior ones absent (fig. 206); chaetotaxy mm 4mm:6:4:2:2(18), macrosetae fine; length of anteromedian macrosetae 0.12 mm. Chaetotaxy of tergites I–X 4:4:4:4:6:6:6:6:6:4. Chaetotaxy of sternites II–X 10:(3)8(3):(2)6–7(2):8:6:6:6:6:7; genital opening of males flanked by 6–9 setae on each side. Chelicerae (fig. 207) 2.3 times as long as broad, palm with 6 setae and 2 microsetae laterally; fixed finger with 10 subequal teeth and a few proximal microtubercles; movable finger with 6 teeth, proximally reduced in size, without isolated subapical tooth (di); gl ratio 0.63; spinneret reduced or absent in males, prominent in female; rallum with 11 blades; serrula exterior with 15 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 9–12 coxal spines, coxa III with 5–8 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 8.2–8.3 (3), 7.0 (Ƥ) times as long as broad; chela (figs 208–209) 6.6–6.7 (3), 5.2–5.5 (Ƥ) times as long as deep; hand of chela 2.76–2.8 (3), 2.3–2.4 (Ƥ) times as long as deep, weakly depressed behind trichobothria ib-isb; fixed chelal finger with 13–15 large triangular, pointed teeth with dental canals and 1–2 proximal vestigial teeth; tip of fixed chelal finger with a modified accessory tooth (td) on antiaxial face; fixed chelal finger at level of est-it with 2–3 teeth occupying 0.1 mm (distance between successive apices 0.038–0.043 mm); distal half of movable chelal finger with 7 large triangular, pointed teeth and 1 proximal reduced, rounded tooth, all with dental canals; proximal half of movable chelal finger with straight, thick marginal lamina; coupled sensilla pc distad of sb (3); basal apodeme of basal chelal finger strongly sclerotized, long, apically truncate and indented; trichobothria eb-esb-ist placed in a straight line, in a male ist a little distad of the line eb-esb; ratio of movable finger/hand 1.3– 1.4 (3Ƥ); ratio of pedipalpal femur/movable finger 1.25–1.3 (3Ƥ); ratio of pedipalpal femur/carapace 1.7–1.75 (3Ƥ).

Measurements (in mm). Body length 1.7 (3). Carapace 0.45–0.53 × 0.41–0.48 (3), 0.50 × 0.525 (?) (Ƥ). Chelicerae 0.455 × 0.20 (3), movable finger length 0.22 (3). Pedipalp: femur 0.76–0.90 × 0.09–0.11 (3), 0.875 × 0.125 (Ƥ); chela 1.03–1.21 × 0.16–0.18 (3), 1.14–1.28 × 0.22–0.24 (Ƥ); hand length 0.43–0.51 (3), 0.51–0.595 (Ƥ); movable finger length 0.61–0.70 (3), 0.65–0.735 (Ƥ).

Remarks. Among the species of the Chthonius fuscimanus group, C. siscoensis is related to C. corsicus and C. giustii , both from Corsica, but it differs from them in many troglomorphic characters: length of chela 1.03–1.21 (3) 1.14–1.28 (Ƥ) in C. siscoensis , 0.655–0.67 (3) in C. corsicus , 0.47–0.54 (3) 0.53–0.61 (Ƥ) in C. giustii ; chela 6.6– 6.7 (3) 5.2–5.5 (Ƥ) times as long as deep in C. siscoensis , 5.5 (3) 5.8 (Ƥ) times as long as deep in C. corsicus , 4.8– 5.15 (3) 4.1–4.3 (Ƥ) times as long as deep in C. giustii ; ratio of pedipalpal femur/carapace 1.7–1.75 in C. siscoensis , 1.35–1.4 in C. corsicus , 1.1–1.2 in C. giustii ; fixed chelal finger at level of est-it with 2–3 teeth occupying 0.1 mm, distance between successive apices 0.038–0.043 mm in C. siscoensis , with 4 teeth occupying 0.1 mm, distanced 0.026 mm in C. corsicus , with 5–6 teeth occupying 0.1 mm, distanced 0.019–0.021 mm in C. giustii .

The above redescription of C. siscoensis incorporates the data reported by Heurtault (1975), Mahnert (1978) and Callaini (1981). The species is known from many localities in central and northern Corsica (Schawaller 1981, Callaini 1981).

Figures

FIGURES 205 – 209. Chthonius (E.) siscoensis Heurtault, 1975 (Corsica, Bastia, Grotta di Brando). 205, male, anterior margin of carapace; 206, id., anterolateral portion of carapace; 207, id., right chelicera; 208, id., tip of fixed chelal finger, dorsal view; 209, id., right chela, lateral view.