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

description: Chthonius (E.) sardous Gardini, 2008
(Figs 191–195, 285)
Chthonius (E.) sardous Gardini 2008a: 11, figs 22–27.
Type locality: Italy, Sardinia, Cagliari Prov., Domusnovas, Grotta Rolfo 1301 Sa/CA (39°20ʹ53ʺN 8°37ʹ11ʺE).
Distribution. Italy: Sardinia.
Diagnosis (Ƥ). An anophthalmic hypogean Chthonius (Ephippiochthonius) from Sardinia that differs from other species of the C. tetrachelatus group in the following combination of characters: movable cheliceral finger without isolated subapical tooth (di) and with spinneret in both sexes; posterior margin of carapace with 2 macrosetae; fixed and movable chelal finger respectively with 33–36 and 16–18 triangular teeth; fixed chelal finger at level of est-it with 4 teeth occupying 0.1 mm (distance between successive apices 0.028 mm); length of chela 1.77–1.83 (3), 1.68–1.77 (Ƥ) mm, length of movable chelal finger 1.07–1.14 (3), 1.02–1.07 (Ƥ) mm; chela 7.6– 7.9 (3), 7.3–7.4 (Ƥ) times as long as deep; ratio of pedipalpal femur/carapace 1.9–2.0 (3Ƥ).
Type material examined. ITALY— Sardinia: Cagliari Prov.— 1 3 (holotype) 1 Ƥ (paratype), Domusnovas, Su Corovau, Grotta Rolfo 1301 Sa/CA, 286 m a.s.l., 22.I.1995, G. Marini leg., under stones; 1T (paratype), id., 21.XI.1994, G. Pani leg., landslip at 200 m from entrance, on rotten wood; 1 3 1T (paratypes), id., 16.IX.1997, J. De Waele & A. Saba leg., in mine tunnel; 1T 2D (paratypes), id., 15.XI.1997, G. Marini leg., at 100 m from entrance; 1 Ƥ (paratype), Iglesias, Corongiu de Mari, Grotta del Cancello 1423 Sa/CA, 190 m a.s.l., 22.VI.1996, J. De Waele leg., on paper in Sala; 1T (paratype), id., 27.X.1996, D. Deidda & R. Spiga leg., on rotten wood at 100 m from entrance.
Other material examined. ITALY— Sardinia: Cagliari Prov.— 1 Ƥ, Domusnovas, Punta Planotzara-S’Ega de is Reburras, Grotta dei Picchi n.c. Sa/CA, 29.X.2006, C. Onnis & S. Papinuto leg.
Description of adults (Ƥ). Marked troglomorphic facies. Integument depigmented. Weak hispid granulation on lateral surfaces of carapace, on cheliceral palm and on dorsodistal surface of chelal hand. Carapace 1.0–1.1 times longer than broad, posteriorly slightly constricted; anterior margin (fig. 191) with long and sharp denticles between median macrosetae, slightly produced as a weak epistome in both sexes; ocular area as in fig. 191, eyes strongly reduced (anterior ocular structures with reduced tapetum); chaetotaxy mm 4mm:6:4:2:2(18), macrosetae fine; length of anteromedian macrosetae 0.14 mm. Chaetotaxy of tergites I–X 4:4:4:4:6:6:6:6:6:4. Chaetotaxy of sternites II–X 9–10:(3)8–9(3):(2)8–9(2):9:6–7:6–7:6:6:7; genital opening of males mostly flanked by 8 (rarely 9) setae on each side. Chelicerae (figs 192–193) 2.3–2.4 times as long as broad, palm with 6 (rarely 5) setae and 2 microsetae laterally, dentition as in figs 192–193, movable cheliceral finger without isolated subapical tooth (di), gl ratio 0.60–0.62; spinneret of males triangular, small, little prominent, larger in females. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 10–14 coxal spines, coxa III with 7–12 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 9.3–9.6 (3), 8.4–9.2 (Ƥ) times as long as broad; chela (figs 194–195) 7.6–7.9 (3), 7.3–7.4 (Ƥ) times as long as deep; hand of chela 2.9–3.1 (3), 2.8–2.9 (Ƥ) times as long as deep, weakly depressed at level of ib-isb and with a plane dorsolateral area between isb and eb; ventrodistal surface of chelal hand with a group of 11–17 gland pores; fixed chelal finger with 33–36 triangular, upright, pointed teeth and, proximally, with 8–10 rounded teeth, all with dental canals, rarely with a small triangular tooth proximad of the modified accessory tooth (td); fixed chelal finger at level of est-it with 4 teeth occupying 0.1 mm (distance between successive apices 0.028 mm); distal half of movable chelal finger with 16–18 triangular, upright, pointed teeth and 17–19 rounded teeth in proximal half, all with dental canals; movable chelal finger rarely with a very small subdistal triangular tooth; coupled sensilla pc distad of sb, between 3rd and 8th teeth; trichobothria as in fig. 200; basal apodeme of movable chelal finger strongly sclerotized, long, fine and rounded apically; ratio of movable finger/hand of chela 1.5–1.6 (3Ƥ); ratio of pedipalpal femur/movable finger 1.2 (3Ƥ); ratio of pedipalpal femur/carapace 1.9–2.0 (3Ƥ).
Measurements (in mm). Body length 2.4–2.7 (3Ƥ). Carapace 0.69–0.71 × 0.62–0.66 (0.58–0.63 anteriorly) (3), 0.64–0.69 × 0.62–0.63 (0.59 anteriorly) (Ƥ). Chelicerae 0.61–0.66 × 0.26–0.29 (3), 0.62–0.64 × 0.27 (Ƥ), movable finger length 0.33–0.34 (3), 0.335–0.34 (Ƥ). Pedipalp: femur 1.30–1.35 × 0.14 (3), 1.26–1.29 × 0.14– 0.15 (Ƥ); chela 1.77–1.83 × 0.225–0.24 (3), 1.68–1.77 × 0.23–0.24 (Ƥ); hand length 0.69–0.70 (3), 0.64–0.69 (Ƥ); movable finger length 1.07–1.14 (3), 1.02–1.07 (Ƥ).
Description of tritonymph. Integument depigmented. Carapace 1.0–1.1 times longer than broad, anterior margin denticulate, without epistome; no eyes or eye-spots; chaetotaxy mm(or m) 4mm (or m):6:4:2:2(18). Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II–X 6:(2)6–7(2):(1)6(1):7:6–7:6:6:6:6. Chelicerae 2.0– 2.1 times as long as broad, palm with 5 (rarely 4) setae and 1 or 2 microsetae laterally; fixed and movable fingers with about 6 teeth; movable finger without isolated subapical tooth (di); gl ratio 0.57–0.59; spinneret as in females. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 2 marginal microsetae, II 4, III 5, IV 5; coxa II with 10–12 coxal spines, coxa III with 6–8 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 7.3–7.6 times as long as broad; chela 6.8–7.0 times as long as deep; hand of chela 2.6–27 times as long as deep, ventral hand surface with 6–10 gland pores; fixed chelal finger with 30–36 triangular, upright, pointed teeth and proximally with 4–6 rounded teeth; fixed chelal finger with 2–3 small triangular tooth proximad of the modified accessory tooth (td); distal half of movable chelal finger with 1–2 distal small teeth followed by 15–16 triangular teeth; proximal half of movable chelal finger with 12–13 apically rounded teeth; coupled sensilla pc distad of b, at level of 10th tooth; ratio of movable finger/hand of chela 1.5–1.6; ratio of pedipalpal femur/movable finger 1.2; ratio of pedipalpal femur/carapace 1.6.
Measurements (in mm). Body length 1.95–2.0. Carapace 0.53–0.57 × 0.52 (0.50 anteriorly). Chelicerae 0.48 × 0.23–0.24, movable finger length 0.25–0.26. Pedipalp: femur 0.88–0.92 × 0.12; chela 1.23–1.30 × 0.175–0.19; hand length 0.46–0.51; movable finger length 0.73–0.78.
Remarks. Among the species of the Chthonius tetrachelatus group, C. sardous is presumably related to the epigean C. siculus because of the serrated dentition of the chelal fingers. They differ clearly by most troglomorphic characters. Comparisons between similar hypogean species were made by Gardini (2008).
C. sardous, which is endemic to karstic complexes of SW Sardinia, represents the most specialized subterranean species of Ephippiochthonius on this island.
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 100-102, DOI: 10.11646/zootaxa.3655.1.1, http://zenodo.org/record/223358