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

description: Chthonius (E.) genuensis Gardini, 1990
(Figs 85–88, 291)
Chthonius (E.) genuensis Gardini 1990: 243, figs 22–26.
Type locality: Italy, Liguria, Genoa Prov., Genova Sestri Ponente, Grotta del Monte Gazzo 401 Li/GE (44°26ʹ27ʺN 8°51ʹ0 2ʺE).
Distribution. Italy: Liguria.
Diagnosis (Ƥ). An anophthalmic hypogean Chthonius (Ephippiochthonius) from Ligurian Apennines that differs from other species of the C. fuscimanus group in the following combination of characters: movable cheliceral finger with isolated subapical tooth (di) proximal with respect to spinneret; pedipalpal hand (in lateral view) without a rounded hump distad of trichobothria ib-isb, weakly depressed at level of ib-isb; pedipalpal fixed finger with 12 triangular teeth, at level of est-it with 4 teeth occupying 0.1 mm (distance between successive apices 0.025 mm); distal half of movable chelal finger with 7 triangular teeth, proximal half with thick and weakly undulated marginal lamina; length of chela 0.75 mm, length of movable chelal finger 0.44 mm; chela 6.25 times as long as deep; ratio of pedipalpal femur/carapace 1.4.
Type material examined. ITALY — Liguria: Genoa Prov.— 1 Ƥ (holotype), Genoa, Sestri Ponente, Grotta del Monte Gazzo (= Gr. del Rospo) 401 Li/GE, 295 m a.s.l., 29.XII.1980, R. Sciaky, A. Torchia & S. Zoia leg.
Description of adult (Ƥ; 3 unknown). Facies weakly troglomorphic. Integument with weak pigmentation. Carapace 1.05 times longer than broad, posteriorly constricted; anterior margin (fig. 85) dentate between median microsetae, without epistome; no eyes or eye-spots (fig. 86); chaetotaxy 4:6:4:2:2(18), macrosetae fine; length of anteromedian macrosetae 0.08 mm. Chaetotaxy of tergites I–X 4:4:4:4:6:6:6:6:6:4. Chaetotaxy of sternites II–IX 8:(3)8(3):(2)7(2):8:7:6:6:6. Chelicerae (fig. 87) 2.1 times as long as broad, palm with 6 setae and 2 microsetae laterally; fixed finger with 6 teeth proximally reduced in size and 5 proximal microtubercles; movable finger with 5 teeth (the distal one bicuspid) and 3 proximal microtubercles; subapical isolated tooth (di) proximal with respect to the spinneret; gl ratio 0.55; spinneret prominent and apically rounded; rallum with 11 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 8 coxal spines, coxae III with 3–4 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 5.9 times as long as broad; chela (fig. 88) 6.25 times as long as deep; hand of chela 2.4 times as long as deep, weakly depressed at level of ib-isb; fixed finger with 13 teeth: the first proximal tooth with tip rounded, the others upright, triangular, all with dental canals; base of fixed finger with 8–9 microtubercles; tip of fixed finger with a modified accessory tooth (td) on antiaxial face; fixed chelal finger at level of est-it with 4 teeth occupying 0.1 mm (distance between successive apices 0.025 mm); distal half of movable finger with 8 teeth: the last proximal tooth with tip rounded, the others upright, triangular, all with dental canals; proximal half of movable chelal finger with thick marginal lamina weakly undulated, becoming thinner between sb and b; coupled sensilla pc on a prominent tubercle halfway between b and sb; trichobothria as in fig. 88, eb-esb-ist placed in a straight line; basal apodeme of movable finger strongly sclerotized, rectangular, apically pointed; ratio of movable finger/hand of chela 1.5; ratio of pedipalpal femur/ movable finger 1.2; ratio of pedipalpal femur/carapace 1.4.
Measurements (in mm). Body length 1.16. Carapace 0.38 × 0.36. Chelicerae 0.33 × 0.155, movable finger length 0.17. Pedipalp: femur 0.53 × 0.09; chela 0.75 × 0.12; hand length 0.29; movable finger length 0.44.
Remarks. Among the species of the Chthonius fuscimanus group, C. genuensis is related to the epigean C. nanus, a widespread species in the same geographical area, from which it differs in many troglomorphic characters. C. genuensis is also related to the hypogean C. zoiai from eastern Liguria, from which it differs in the position of the isolated subapical tooth (di) on the movable cheliceral finger (di proximad with respect to spinneret in C. genuensis, level with spinneret in C. zoiai) and in the smaller size [length of femur 0.53 (Ƥ) mm in C. genuensis, 0.65–0.74 (Ƥ) mm in C. zoiai; length of chela 0.75 (Ƥ) mm in C. genuensis, 0.92–1.07 (Ƥ) mm in C. zoiai].
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 48-50, DOI: 10.11646/zootaxa.3655.1.1, http://zenodo.org/record/223358