Ephippiochthonius tetrachelatus (Preyssler, 1790) Preyssler, 1790

Zaragoza, Juan A., 2017, Revision of the Ephippiochthonius complex in the Iberian Peninsula, Balearic Islands and Macaronesia, with proposed changes to the status of the Chthonius subgenera (Pseudoscorpiones, Chthoniidae), Zootaxa 4246 (1), pp. 1-221 : 120-121

Ephippiochthonius tetrachelatus (Preyssler, 1790) , n. comb.

( Figs 1–3 , 4–7 , 32–39 )

Type locality. Czech Republic, Prague, Karlovo náměstí (50°04′32″N, 14°25′11″E; 209 m a.s.l.).

Distribution. Western Palaearctic Region, chiefly Mediterranean; introduced to Eastern Canada, U.S.A. (including Hawaii), Cuba, Argentina, Seychelles and southwestern Australia ( Gardini 2013; Harvey 2013). Records for the Iberian Peninsula and Balearic Islands are given in Zaragoza (2007) and Zaragoza & Vadell (2013).

Diagnosis (♂ ♀). A medium-sized, epigean Ephippiochthonius species of the tetrachelatus -group. Movable cheliceral finger without isolated subapical tooth (di) and with spinneret in both sexes, lyrifissure ldb present; two pairs of eyes with lenses, posterior margin of carapace with 2 macrosetae or rarely with 2 macrosetae and with 1 lateral microseta on one side; pedipalp with femoral chaetotaxy 3:6:2:5:1; chelal hand not depressed or very weakly at level of ib / isb, with a long, low and rounded hump distad of ib / isb and moderate slope between trichobothria ib / isb and eb; fixed chelal finger with 14–22 teeth; distal half of movable chelal finger with 6–8 pointed teeth with dental canals, proximal half without a marginal lamina, with 5–9 low vestigial teeth; pedipalpal femur (♂) 5.4–7.5, (♀) 5.3–7.0 times longer than broad, length (♂) 0.47–0.69 mm, (♀) 0.52–0.76 mm; chela (♂) 4.4–5.8, (♀) 4.2–5.8 times longer than deep, length (♂) 0.65–0.95 mm, (♀) 0.71–1.04 mm; ratio movable chelal finger/chelal hand (♂) 1.3–1.4, (♀) 1.2–1.3; all chelal lyrifissure patterns present with their standard complements.

Non-type material examined. Czech Republic, Prague: Chodov , 2 ♂ ( FSC), 23.V.1998, under stones; Dolní Počernice , 2 ♂, 3 ♀ (1 ♂, 2 ♀ FSC; 1 ♂, 1 ♀ DEUA), 31.VIII.1998, under stones; Čiklova street, 2 ♂ (FSC, DEUA), 01.IX.1998, leaf litter; Malostranský cemetery, 2 ♂ (FSC), 21.IX.1998, leaf litter; Husovy sady, 1 ♂, 1 ♀ (FSC), 21.IX.1998, leaf litter; Královice-Hájek (U. Markéty), 5 ♂, 4 ♀ (2 ♂, 2 ♀ FSC; 3 ♂, 2 ♀ DEUA), 01.V.1999, under the stones; Tyršův vrch, 1 ♂, 1 ♀ (FSC), 13.XII.1999, leaf litter; Botanic garden, 1 ♀ (FSC), 29.VIII.2000, under a piece of wood; all leg. F. Šťáhlavský.

Description (♂ ♀). Medium-sized epigean species. Integument pigmented; marked hispid granulation on lateral surfaces of carapace, on cheliceral hand and on bases of chelal fingers.

Carapace equal to or slightly shorter or longer than broad and weakly constricted posteriorly; medial part of anterior margin weakly prominent, rarely with epistome, and strongly dentate; anterior eyes with strongly convex lens (diameter 0.040–0.060 mm), 0.030–0.040 mm from anterior margin of carapace, posterior eyes more with more or less weakly convex lens than anterior pair, both pairs of eyes with reflecting tapeta. Chaetotaxy: 18 macrosetae and 2 preocular microsetae on each side, rarely one, setal formula mm 4mm:6:4:2:2, anteromedial setae 0.07–0.11 mm long; 4 lyrifissures anteriorly and 2 posteriorly.

Chelicera ( Fig. 4 ) with 6 setae and 2 lateral microsetae on hand, seta vb short and almost twice as long as microsetae; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 6–9 teeth decreasing in size proximally, 1–2 distal teeth distinctly larger than others and 4–6 proximal microtubercles. Movable finger without an isolated subapical tooth (di), with 5–6 teeth decreasing in size proximally, the distal tooth larger than others, 3–5 proximal microtubercles; spinneret prominent in female, lower and more rounded in male; seta gl 0.53–0.66 from base of movable finger. Rallum with 11 blades. Serrula exterior with 14 blades, serrula interior 12 blades.

Chaetotaxy of tergites 4:4:4:4:6:6:6:6:1T2T1:4:1T2T1:0, tergites IX and XI each with 2 sublateral tactile setae. Chaetotaxy of sternites 10–11:(3)8–10(3):(2)7–8(2):8–9:6:6:6:6: 2T1T2:0:2, lateral setae on sternite III microsetal in size, sternite X with 2 submedial tactile setae ( Fig. 5 ); in addition, genital notch of male flanked by 6–9 setae on each side and 4+4 internal glandular setae.

Pedipalpal coxa with 5 setae (including 2 on manducatory process); coxa I 3 + 3 marginal microsetae, distal marginal seta of pedipalpal disk distinctly longer than the marginal seta of coxa I; II 4 + 7–12 bipinnate coxal spines, III 5 + 3–7 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Pedipalp with femoral chaetotaxy 3:6:2:5:1, rarely 3 setae in the posterior dorsal row of one chela and 2 in that of the other. Chela ( Figs 1–3 ) with hand not depressed or very weakly at level of ib / isb, with a long, low and rounded hump distad of ib / isb and moderate slope between trichobothria ib / isb and eb; dorsal-antiaxial surface of the chelal hand between the hump and trichobothria eb / esb flattened, limited by a marked edge; ventral intercondylar bow-like protuberance (ip) present ( Figs 34, 35, 39 ); chaetotaxy 4:5:3, seta ph3 lacking, setae ih1, ih3 and ih4 approximately level with trichobothria ib / isb; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 14–22 mostly pointed and weakly reclined teeth progressively decreasing in size and with dental canals, 1‒2 distal ones small, 2–4 most proximal teeth rounded, 2–4 microtubercles at base; tip of finger with an accessory tooth (td) on antiaxial face; tip of fixed chelal finger of male with a deep hollow on paraxial face and subdistal protuberance (sp); one pair of very short antiaxial sensory setae (as) at the base, level with or proximad of lyrifissure fb, distance between them distinctly shorter than finger depth at base; 3–4 teeth, rarely 5, at level of est / it occupying 0.1 mm, distance between successive apices 0.024–0.040 mm. Distal half of movable finger with 6–8 pointed teeth with dental canals, the distal one small (rarely absent); proximal half without marginal lamina, with 5–9 low vestigial teeth reaching trichobothrium sb or halfway between sb and b, mostly with dental canals; basal condyle (bc) enlarged and apodeme long and apically indented ( Figs 6, 7 , 38 ); coupled sensilla pc halfway between b and sb, mostly closer to sb. Trichobothria as in Figs 1‒2 ; trichobothria ebesb-ist mostly in a straight line, ist always distad of esb and well proximad of lyrifissure fb. All chelal lyrifissure patterns present with their standard complements ( Figs 33, 36, 37 ).

Measurements and ratios. The following data are from the description of Gardini (2013), who measured a large number of specimens from many populations assigned to this species: Male, followed by female in square brackets: Body 1.3–1.8 [1.4–1.9]. Carapace 0.35–0.50/0.36–0.46 (0.9–1.1) [0.37–0.55/0.38–0.54] Chelicera 0.29– 0.41/0.14–0.19 (1.9–2.2) [0.32–0.45/0.16–0.21], movable finger length 0.13–0.19 [0.16–0.23]. Pedipalp: femur 0.47–0.69/0.08–0.12 (5.4–7.5) [0.52–0.76/ 0.09–0.14 (5.3–7.0)], chela 0.65–0.95/0.12–0.17 (4.4–5.8) [0.71–1.04/ 0.14–0.23 (4.2–5.8)], hand 0.27–0.42 (2.0–2.5) [0.30–0.44 (1.8–2.3)], movable finger 0.38–0.56 [0.40–0.60]; ratio movable finger/hand 1.3–1.4 [1.2–1.3], femur/movable finger 1.2–1.4, femur/carapace 1.3–1.5.

Remarks. The presence of E. tetrachelatus seems less frequent in the Iberian Peninsula than in Italy and Central Europe. However, it should be taken into consideration that a disproportionate number of the samples of Iberian Chthoniidae studied in both the previous literature and the present work come from hypogean environments in comparison to those collected from epigean environments. Most literature records of E. tetrachelatus for the Iberian Peninsula need to be verified by restudying the available specimens concerned, and it will not be surprising if some of them are found to correspond to other species [e.g. misidentifications of E. andalucia n. sp. by Zaragoza & Pérez (2013) and Zaragoza (2013a)].

Figures

FIGURES 1 – 3. Ephippiochthonius tetrachelatus (Preyssler, 1790) n. comb., chela of male from Královice-Hájek, U. Markéty, Prague, Czech Republic. 1, antiaxial view, slightly dorsal; 2, dorsal view; 3, ventral view. Abbreviations: ap: apodeme; as: antiaxial sensory setae; bc: basal condyle; ca: antiaxial condyle; cp: paraxial condyle; eh: edge; fa: antiaxial lyrifissure of fixed chelal finger; fb: basal lyrifissure of fixed chelal finger; fd 1, fd 2, fd 3: dorsal lyrifissures of the fixed chelal finger; hd: distal lyrifissure of chelal hand; hp: proximal lyrifissure of chelal hand; ip: intercondylar protuberance; ma 1, ma 2: antiaxial lyrifissures of movable chelal finger; mv 1, mv 2: ventral lyrifissures of movable chelal finger; sp: subdistal protuberance; td: accessory tooth.

FIGURES 4 – 7. Ephippiochthonius tetrachelatus (Preyssler, 1790) n. comb., males from Královice-Hájek, U. Markéty, Prague, Czech Republic (4 ‒ 6) and male from Sea Cliff, Nassau, New York, U. S. A. (7). 4, left chelicera; 5, external genital area; 6, basal portion of movable chelal finger; 7. Basal portions of chelal fingers. Abbreviations: ap: apodeme; bc: basal condyle; ca: antiaxial condyle; fo: fixed chelal finger foramen; ip: intercondylar protuberance; ls: lateral setae; ldb, ldst, ldt, lvb, lve, lvt: lyrifissures associated with cheliceral setae.

FIGURES 32 – 39. Ephippiochthonius tetrachelatus (Preyssler, 1790) n. comb., SEM images. Female, Královice-Hájek, U. Markéty, Prague, Czech Republic (32 – 37) and female, Madeira (38, 39). 32, habitus, antiaxial view, slightly dorsal; 33, detail of chelal fingers, antiaxial view (some adhesive remains between fingers); 34, distal portion of chelal hand and bases of fingers, paraxial view; 35, distal portion of chelal hand and base of movable finger, ventral view; 36, distal portion of chelal hand, dorsal view; 37, medial portion of chelal hand, dorsal view; 38, basal portion of movable chelal finger, antiaxial view; 39, distal portion of movable chelal finger, ventral view. See Material and methods for abbreviations.