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

description: Chthonius (E.) berninii Callaini, 1983
(Figs 18–27, 286)
Chthonius (E.) gibbus (not Beier, 1953): Mahnert 1975: 186, fig. 1b (Majorca: misidentification). Chthonius (E.) berninii Callaini 1983b: 406, figs Ia–g, IIa–b; Gardini 2008a: 5; Gardini 2008b: 630; Gardini 2011: 825. Chthonius (E.) bauneensis Callaini 1983b: 415, figs IIIa–g, IVa–b (n. syn.).
Chthonius (E.) aegatensis Callaini 1989: 138, figs 1A–F (n. syn.).
Type locality: Italy, Sardinia, Cagliari Prov., Narcao, Colle della Campanasissa (39°12ʹ0 4ʺN 8°46ʹ18ʺE).
Distribution. Sicily (Egadi Isl.), central and southern Sardinia, Majorca.
Diagnosis (Ƥ). An eyed epigean Chthonius (Ephippiochthonius) that differs from other species of the C. fuscimanus group in the following combination of characters: movable cheliceral finger with isolated subapical tooth (di), spinneret mostly absent in males; carapace with 2 preocular microsetae on each side; ocular series with 6 macrosetae; posterior margin of carapace with 4 macrosetae, pedipalpal hand (in lateral view) with a rounded hump distad of trichobothria ib-isb; fixed chelal finger with 12–16 triangular teeth (proximal rounded teeth excepted); proximal half of fixed chelal finger with 2–5 rounded and spaced teeth, marginal lamina not prominent; proximal half of movable chelal finger with thick marginal lamina, with rounded or vestigial teeth with high base; genital opening of males flanked by 5–8 setae on each side, partly scattered along sides of genital opening; length of chela 0.45–0.57 (3), 0.50–0.66 (Ƥ) mm, length of movable chelal finger 0.26–0.35 (3), 0.28–0.40 (Ƥ) mm; chela 4.0– 5.3 (3), 3.6–4.6 (Ƥ) times as long as deep; ratio of pedipalpal femur/carapace 1.0–1.2.
Type material examined. ITALY — Sicily: Trapani Prov.— 1 3 1 Ƥ (paratypes), “Marettimo 5.4.82 Contrada Cisterna. humus e fogliame sotto macchia mediterranea” “ Chthonius aegatensis Callaini paratypus ” (MSNG). Sardinia: Cagliari Prov.— 1 3 1 Ƥ (paratypes), “Sardegna. Colle della Campanasissa 22.3.76 15 Km. da Narcao. humus di leccio e corbezzolo” “ Chthonius berninii Callaini paratypus ” (MSNG). Sardinia: Nuoro Prov.— 1 3 (with broken opisthosoma) 1 Ƥ (paratypes), “Sardegna. Baunei 4.4.78 fogliame di leccio” “ Chthonius bauneensis Callaini paratypus ” (MSNG).
Other material examined. ITALY — Sardinia: Cagliari Prov.— 2 3, Arbus, near Miniera Ingurtosu, 257 m a.s.l., 14.XI.2009, G. Ruzzante leg., under stone; 2 Ƥ, Ballao, Rio Bintinoi, 2.XII.1986, L. Fancello & P. Leo leg.; 1 3 1 Ƥ, Burcei, Monte Sette Fratelli, 26.I.1990, L. Fancello & P. Leo leg.; 1 Ƥ, id., 8.III.1991; 1 3, id., 17.V.1991; 4 Ƥ, Cagliari, Cala Regina, 15.III.1989, L. Fancello & P. Leo leg.; 2 Ƥ, Carbonia, Barbusi, 11.XI.1986, L. Fancello & P. Leo leg.; 1 Ƥ, Carbonia, Monte Sirai, 22.XII.1990, L. Fancello & P. Leo leg.; 1 3 3 Ƥ, Domus de Maria, 29.XII.1991, P. Leo leg.; 1 3 1 Ƥ, id., Cala de sa Musica, 56 m a.s.l., 31.X.2009, G. Ruzzante leg., under stone; 1 3 3 Ƥ, id., Punta Su Pisu, 19 m a.s.l., XII.2007, G. Ruzzante leg.; 1 Ƥ, id., V.2008; 4 3 3 Ƥ, id., XII.2008; 3 Ƥ, id., I.2009; 2 3 6 Ƥ, id., XI.2009, dried faggots; 3 3 3 Ƥ, Domusnovas, 12.I.1990, L. Fancello & P. Leo leg.; 1 Ƥ, Escalaplano, near provincial road n. 13, 230 m a.s.l., 14.III.2010, C. Torti leg., Mediterranean low scrub; 1 Ƥ, Sant’Antioco, Isola il Toro, 10.V.1988, R. Poggi leg. (MSNG); 1 3 1 Ƥ 1T, id., Isola Sant’Antioco, Cala Lunga, 11.II.1984, L. Fancello & P. Leo leg.; 1 Ƥ, id., 4.II.1990, L. Fancello leg.; 2 3, near Narcao, 1.IV.1997, S. Vit leg., mature Mediterranean forest; 3 3, Pula, Pixina Manna, 15.II.1992, L. Fancello & P. Leo leg.; 2 3 4 Ƥ, Santadi, 17.XII.1993, L. Fancello & P. Leo leg.; 2 Ƥ, id., Punta Sébera, Grotta 3a di Rocca Gravellus 1622 Sa/CA, 780 m a.s.l., 19.I.1997, J. De Waele & M. Pisano leg., under stone; 1 Ƥ 2T, Sarroch, 11.IV.1989, L. Fancello leg.; 1 3 2 Ƥ, id., 25.II.1991, L. Fancello & P. Leo leg.; 4 3 3 Ƥ 1T, id., 29.X.1986; 3 Ƥ, id., 6.V.1991; 1 3 1 Ƥ, Siliqua, Orbai, 1.IV.1991, G. Gardini leg., holm oak; 3 3 3 Ƥ, Soleminis, Monte Arrubiu, 390 m a.s.l., 10.X.2009, G. Ruzzante leg., under stone; 1 3, Teulada, 3.III.1991, P. Leo leg.; 2 3, Uta, Genna de su Cerbu, 8.XI.1989, L. Fancello leg.; 1 3 1 Ƥ 1T, Villacidro, 15.III.1987, P. Leo leg.; 4 Ƥ, Villasimius, 12.I.1993, L. Fancello & P. Leo leg.; 1 Ƥ, id., Isola Serpentara, 9.V.1988, R. Poggi leg. (MSNG). Sardinia: Nuoro Prov.— 1 3 2 Ƥ, Baunei, 18.XII.1992, P. Leo leg.; 1 3, Baunei, forestal area of Monte Lopene, 710 m a.s.l., 21.V.2010, C. Torti leg., Pinus pinaster; 1 Ƥ, near Baunei, 7.XII.1991, L. Fancello & P. Leo leg.; 1 3 2T, Baunei, near Perda Longa, 20 m a.s.l., [no date], C. Torti leg., scrub on limestone; 3 3 2 Ƥ, id., San Pietro, 550 m a.s.l., 5.VII.1984, C. Torti leg., scrub on limestone; 2T, Supramonte di Baunei, Grotta di Su Canale n.c. Sa/NU, X.2003, P. Marcia leg.; 1 3, Gairo, Gairo Cardedu, 26.VI.1984, C. Torti leg., holm oak; 1 3, id., Gairo Marina, 5/ 14.IV.2009, C. Torti leg.; 2 3, Lanusei, 10.I.1993, L. Fancello leg.; 2 3 1 Ƥ, id., near main road n. 198 km 89, 2.VII.1984, C. Torti leg., holm oak on granite; 3 3 5 Ƥ, id., main road n. 198 km 90, 19.VI.1985, C. Torti leg., holm oak; 1 3 1T, Ollolai, between SP 29 and SP 22, 800 m a.s.l., 12.III.2009, C. Torti leg., holm oak; 1 Ƥ, Perdasdefogu, 15.III.1990, L. Fancello & P. Leo leg. Sardinia: Oristano Prov.— 1 3, Ardauli, 30.XII.1994, L. Fancello & P. Leo leg.
Description of adults (Ƥ). Integument pigmented, carapace, tergites, chelicerae and pedipalps yellowbrown; lateral surface of carapace, cheliceral palm and base of movable chelal finger with weak hispid granulation. Carapace 0.9–1.1 times longer than broad, subquadrate; anterior margin (figs 18–19) strongly dentate between median macrosetae, with small epistome in both sexes; ocular area as in fig. 20, four eyes, the anterior ones with weakly convex lens (diameter 0.030–0.038 mm), posterior eyes more reduced, with weak lens; distance from anterior eyes to anterior margin of carapace 0.024–0.030 mm; chaetotaxy mm 4mm:6:4:2:4 (20), rarely one preocular microseta, macrosetae fairly fine; length of anteromedian macrosetae 0.063–0.082 mm; posterolateral macrosetae shorter than posteromedian ones. 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 II rarely with 8, 9 or 11 setae, st. III 7, st. IV 6–8, st. V 9; genital opening of males (fig. 25) flanked by 5–8 setae on each side, partly scattered; genital opening of variable width, mostly with straight, more or less opened sides (i.e. 3 from Sarroch, 29.X.1986). Chelicerae (figs 21–23) 1.9–2.2 times as long as broad, palm with 6 setae and 2 (rarely 1) microsetae laterally; fixed finger with 4–7 teeth proximally reduced in size and 5–8 proximal microtubercles; movable finger with an isolated subapical tooth (di), at the same level—or a little proximad—of the spinneret, and with 4–7 teeth proximally reduced in size and a few proximal microtubercles; gl ratio 0.55–0.61; spinneret mostly absent in males, in females keel-like or prominent, rarely only weakly raised (figs 21–22), cone-shaped and apically rounded (fig. 23); rallum with 11 blades; serrulae interior and exterior respectively with 12 and 14 or 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 5–12 (mostly 5–8) coxal spines, coxa III with 2– 6 (mostly 4–5) coxal spines; intercoxal tubercle bisetose. Pedipalp (figs 24, 26–27): femur 4.3–5.3 (3), 4.4–5.1 (Ƥ) times as long as broad, basally with moderate hispid granulation; chela 4.0–5.3 (3), 3.6–4.6 (Ƥ) times as long as deep; hand of chela 1.7–2.1 (3), 1.55–1.9 (Ƥ) times as long as deep, smooth, with an evident round hump distad of ib-isb and a marked hollow—with thicker cuticule—just before the base of movable finger; fixed chelal finger usually with 14–15 (rarely 12 or 16) teeth: 1 or 2 distal, small and acuminate teeth, 10–14 large, triangular, faintly reclined teeth, all with dental canals, and 1–5 proximal rounded teeth with dental canals; base of fixed finger with 4–8 microtubercles; tip of fixed finger with a modified accessory tooth (td) on antiaxial face; pedipalpal fixed finger at level of est-it with 5–6 teeth occupying 0.1 mm (distance between successive apices 0.022–0.023 mm); distal half of movable finger rarely with 1 or 2 distal denticles and with 6–11 triangular and upright teeth with dental canals; proximal half of movable finger with 5–9 rounded vestigial teeth, without dental canals, on high marginal lamina; base of movable finger with few microtubercles; coupled sensilla pc mostly at level of sb; trichobothria as in figs 26–27, eb-esb-ist mostly placed in a straight line or with ist distad of the line eb-esb, ist sometimes at level of esb; basal apodeme of movable finger strongly sclerotized, variable in shape, mostly slightly curved and apically truncate; ratio of movable finger/hand of chela 1.2–1.65 (3), 1.2–1.5 (Ƥ); ratio of pedipalpal femur/movable finger 1.15–1.3 (3Ƥ); ratio of pedipalpal femur/carapace 1.0–1.2 (3Ƥ).
Measurements (in mm). Body length 1.0–1.2 (3) 1.3–1.4 (Ƥ). Carapace 0.28–0.35 × 0.28–0.34 (0.26–0.30 anteriorly) (3), 0.30–0.40 × 0.32–0.40 (0.32–0.35 anteriorly) (Ƥ). Chelicerae 022–0.27 × 0.11–0.135 (3), 0.25– 0.32 × 0.13–0.16 (Ƥ), movable finger length 0.12–0.15 (3), 0.135–0.17 (Ƥ). Pedipalp: femur 0.32–0.40 × 0.06– 0.08 (3), 0.36–0.45 × 0.07–0.10 (Ƥ); chela 0.45–0.57 × 0.10–0.12 (3), 0.51–0.66 × 0.13–0.16 (Ƥ); hand length 0.19–0.24 (3), 0.23–0.27 (Ƥ); movable finger length 0.26–0.35 (3), 0.29–0.40 (Ƥ).
Description of tritonymph. Integument with weak pigmentation and weak hispid granulation. Carapace as long as broad (1.0), anterior margin with small epistome; eyes as in adults (diameter of anterior eyes 0.024 mm); chaetotaxy m 4m:6:4:2:4 (20), length of anteromedian macrosetae 0.059 mm. Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II–X 5:(2)6(2):(1)6(1):7:6:6:6:6:5. Chelicerae 1.9–2.0 times as long as broad, palm with 5 setae and 1 lateral microseta; fixed finger with 6–8 teeth, movable finger with an isolated subapical tooth (di) and 3–5 contiguous teeth; gl ratio 0.59–0.60. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 2–3 + 2 marginal microsetae, II 4, III 5, IV 5; coxa II with 4–6 coxal spines, coxa III with 2–4 coxal spines intercoxal tubercle bisetose. Pedipalp: femur 4.6–4.8 times as long as broad; chela 4.3–4.7 times as long as deep; hand of chela 1.8–1.9 times as long as deep, with a slight round hump distad of ib-isb and a marked hollow—with thicker cuticle—just before the base of the movable finger; fixed chelal finger on the whole with 11–13 teeth: 2 very small distal teeth, 9–11 triangular, large teeth and 1–2 proximal rounded teeth; base of fixed finger with microtubercles; tip of fixed finger with a modified accessory tooth (td) on antiaxial face; distal half of movable finger with 1 distal denticle and 6–7 upright, triangular teeth with dental canals; proximal half of movable finger with 5 rounded vestigial teeth, without dental canals, on high marginal lamina; base of movable finger with 4–5 microtubercles; coupled sensilla pc distad of b; ratio of movable finger/hand of chela 1.35–1.4; ratio of pedipalpal femur/movable finger 1.1–1.2; ratio of pedipalpal femur/carapace 1.0.
Measurements (in mm). Body length 1.0–1.1. Carapace 0.28–0.30 × 0.29–0.31 (0.245–0.26 anteriorly). Chelicerae 0.22–0.23 × 0.11–0.12, movable finger length 0.11–0.115. Pedipalp: femur 0.29–0.32 × 0.06–0.07; chela 0.44–0.475 × 0.094–0.11; hand length 0.18–0.20; movable finger length 0.26–0.27.
Remarks. Chthonius berninii was described by Callaini (1983, p. 406) from specimens of both sexes from southern Sardinia and compared to C. gibbus, C. siculus and C. tuberculatus Hadži, 1937. In the same paper, Callaini (1983, p. 415) described C. bauneensis from specimens of both sexes from central-eastern Sardinia (type loc.: Baunei) and compared it to C. machadoi Vachon, 1940, C. cassolai and C. parmensis. Finally, C. aegatensis was described by Callaini (1989) from specimens of both sexes from Marettimo Is. (Sicily) and compared to C. berninii and C. bauneensis.
Comparison between original descriptions and drawings of C. berninii, C. bauneensis and C. aegatensis shows that they share most morphological characters, i.e. shape of chelal hand, dentition of fixed and movable chelal fingers, shape of marginal lamina of movable chelal finger, posterior margin of carapace with 4 macrosetae, movable cheliceral finger with isolated subapical tooth (di) and without—or with reduced—spinneret in males. The dimensions and ratios are also similar or identical, as emphasized by Callaini (1989) when comparing C. aegatensis and C. berninii.
Callaini (1983b, p. 416, fig. IIId) described the unusual shape of genital opening in males of C. bauneensis (with narrow notch flanked by 5–7 irregularly scattered setae), and in the subsequent description of C. aegatensis he noted the same structure was present in males of this species (Callaini 1989, p. 139, fig. 1C).
Examination of the material listed above, including paratypes of both sexes of C. berninii, C. bauneensis and C. aegatensis, shows that above-mentioned characters are really shared, as could be supposed by comparing the original descriptions. Callaini (1989, p. 139) described the movable chelal finger of C. aegatensis as lacking a marginal lamina and this was the only character used to distinguish C. aegatensis from C. bauneensis. However, a marginal lamina is evident in his figures (1E, F, page 141) and it is present in both the examined paratypes of C. aegatensis. Callaini (1989, p. 142) stated that C. aegatensis and C. berninii show identity in morphological shape, measurements and ratios of pedipalps, but can be easily distinguished by the shape of genital opening in males (with narrow notch in C. aegatensis, triangular and with broad notch in C. berninii). The Sardinian males examined here show a genital opening of variable width, mostly with straight-sided, more or less broad notch (e.g. 3 from Sarroch, 29.X.1986; Narcao, 1.IV.1997; Lanusei, 19.VI.1985). In the absence of any reliable differences, following synonymies are proposed: Chthonius (E.) bauneensis Callaini, 1983 and C. (E.) aegatensis Callaini, 1989 are junior subjective synonyms of Chthonius (E.) berninii Callaini, 1983 (n. syn.).
Among the species of the C. fuscimanus group, C. berninii is closely related to the hypogean C. cassolai from Sardinia because of the number of macrosetae on the posterior margin of carapace, the shape of chelal hand and marginal lamina. For comparisons between C. berninii and C. cassolai see Remarks under the latter species.
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 16-20, DOI: 10.11646/zootaxa.3655.1.1, http://zenodo.org/record/223358