Chthonius ligur, 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 : 66-68

Chthonius (E.) ligur n. sp.

( Figs 129–137 , 293 )

Type locality: Italy, Liguria, Imperia Prov., around Baiardo (43°54ʹ0 0ʺN 7°42ʹ47ʺE).

Distribution. Italy: Liguria.

Diagnosis (Ƥ). A microphthalmic epigean Chthonius (Ephippiochthonius) from Ligurian pre-Alps that differs from other species of the C. fuscimanus group in the following combination of characters: movable cheliceral finger without isolated subapical tooth (di), spinneret absent or weakly raised in males; fixed chelal finger at level of est-it with 5 teeth occupying 0.1 mm (distance between successive apices 0.020–0.022 mm); length of chela 0.51–0.53 (3), 0.56–0.57 (Ƥ), length of movable chelal finger 0.30–0.305 (3), 0.32–0.33 (Ƥ); chela 5.1–5.3 (3), 4.6–4.75 (Ƥ) times as long as deep; ratio of movable chelal finger/hand of chela 1.3–1.4 (3Ƥ), ratio of pedipalpal femur/carapace 1.1–1.25 (3Ƥ).

Type material. ITALY— Liguria: Imperia Prov.— 1 3 (holotype), near Baiardo (43°54ʹ0 0ʺN 7°42ʹ47ʺE), 800 m a.s.l., 6.XI.1981, S. Zoia, G. Gardini & A. Boato leg., mixed wood on flysch; 2 Ƥ (paratypes), near Baiardo, 800 m a.s.l., 17.VI.1982, L. Ansaldo, C. Torti & S. Zoia leg.; 1 Ƥ (paratype), Diano San Pietro, Mt Colletto, 400 m a.s.l., 30.V.2007, T. Ardissone leg., sieved in Quercus pubescens wood. Liguria: Savona Prov.— 1 3 2 Ƥ (paratypes), Vendone, Curenna, 400 m a.s.l., 15.III.1982, G. Gardini & R. Rizzerio leg., sieved in chestnut wood (holotype deposited in MHNG, paratypes in G. Gardini coll., Genoa).

Derivatio nominis. The Latin adjective ligur means belonging to, or related to, the Italian region Liguria.

Description of adults (Ƥ). Integument with weak pigmentation, carapace, tergites, chelicerae and pedipalps yellow-brown; hispid granulation on lateral surface of carapace and on cheliceral palm. Carapace 0.9–1.1 times longer than broad, subquadrate, posteriorly slightly constricted; anterior margin (figs 129–131) strongly dentate between median macrosetae, sometimes with small epistome; ocular area as in fig. 132, anterior eyes with weakly convex lens (diameter 0.03–0.04 mm) with tapetum, posterior eyes absent or reduced to a very pale cuticular area with hispid granulation; distance from anterior eyes to anterior margin of carapace 0.020–0.025 mm; chaetotaxy mm 4mm:6:4:2:2 (18), macrosetae rather thick; length of anteromedian macrosetae 0.08–0.09 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)7(2):8:6:6:6:6:7; sternite IV rarely with 6 setae; genital opening of males flanked by 5–7 setae on each side. Chelicerae (figs 133–134) 2.0 times as long as broad, palm with 6 setae and 2 microsetae laterally; fixed finger with 6–9 teeth proximally reduced in size and 9– 10 proximal microtubercles; movable finger without isolated subapical tooth (di), with 6–7 teeth and 3–5 proximal microtubercles; gl ratio 0.55–0.61; spinneret absent or weakly raised in males, prominent, apically widely rounded in females; rallum with 11 blades; serrulae interior and exterior respectively with 12 and 14 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 5–8 coxal spines, coxa III with 3–5 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 5.2–5.5 (3), 4.8–5.0 (Ƥ) times as long as broad, with laterobasal hispid granulation; chela (figs 135–137) 5.1–5.3 (3), 4.6–4.75 (Ƥ) times as long as deep; hand of chela 2.1–2.2 (3), 1.9–2.0 (Ƥ) times as long as deep, depressed at level of ib-isb, with a weak hump distad of ib-isb; proximal half of chelal hand cone-shaped, weakly constricted towards the base; fixed finger with 11–13 large, triangular, faintly reclined teeth with dental canals: the first distal one very small, the first one or two proximal teeth apically rounded, sometimes reduced; base of fixed finger with 6–8 microtubercles; tip of fixed finger with a modified accessory tooth (td) on antiaxial face; fixed chelal finger at level of est-it with 5 teeth occupying 0.1 mm (distance between successive apices 0.020–0.022 mm); distal half of movable chelal finger with 6–7 upright, triangular teeth with dental canals and 1–2 vestigial proximal teeth; proximal half of movable finger with thick marginal lamina weakly irregular and undulated; coupled sensilla pc distad of sb; trichobothria as in figs 136–137, ist a little proximad of line eb-esb; basal apodeme of movable finger strongly sclerotized, squat; ratio of movable finger/hand of chela 1.4 (3), 1.3–1.4 (Ƥ); ratio of pedipalpal femur/movable finger 1.2 (3Ƥ); ratio of pedipalpal femur/carapace 1.1–1.25 (3Ƥ).

Measurements (in mm). Body length 1.0 (3), 1.1–1.2 (Ƥ). Carapace 0.29–0.325 × 0.28–0.30 (0.26 anteriorly) (3), 0.315–0.35 × 0.33–0.35 (0.29–0.31 anteriorly) (Ƥ). Chelicerae 0.235–0.245 × 0.115–0.12 (3), 0.27–0.275 × 0.13–0.135 (Ƥ), movable finger length 0.12–0.13 (3), 0.13–0.135 (Ƥ). Pedipalp: femur 0.36–0.365 × 0.065–0.07 (3), 0.385–0.40 × 0.08 (Ƥ); chela 0.51–0.53 × 0.10 (3), 0.56–0.57 × 0.12–0.125 (Ƥ); hand length 0.21–0.22 (3), 0.24 (Ƥ); movable finger length 0.30–0.305 (3), 0.32–0.33 (Ƥ).

Remarks. Among the species of the Chthonius fuscimanus group without an isolated subapical tooth (di) on movable cheliceral finger, C. ligur n. sp. is closely related to the epigean C. gallii from western Liguria (see Remarks under latter for comparison).

The sole objective character to distinguish between C. ligur and C. intemelius , both epigean species from western Liguria, is the absence (in C. ligur ) and the presence (in C. intemelius ) of the isolated subapical tooth (di) on the cheliceral movable finger (see Remarks under C. boldorii for a similar case).

Figures

FIGURES 129 – 135. Chthonius (E.) ligur n. sp. 129, male holotype, anterior margin of carapace; 130, male paratype (Vendone, Curenna), id.; 131, female paratype (near Baiardo, 17. VI. 1982), id.; 132, male holotype, anterolateral portion of carapace; 133, id., left chelicera; 134, female paratype (near Baiardo, 17. VI. 1982), right chelicera; 135, male holotype, tip of fixed chelal finger, dorsal view.

FIGURES 136 – 137. Chthonius (E.) ligur n. sp. 136, male holotype, right chela, lateral view; 137, female paratype (near Baiardo, 17. VI. 1982), 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.