Chthonius villacarrillo, Zaragoza, Juan A. & Pérez, Toni, 2013

Zaragoza, Juan A. & Pérez, Toni, 2013, Hypogean pseudoscorpions (Arachnida) from Jaén province (Andalusia, Spain), with descriptions of four new species and a new synonymy, Zootaxa 3700 (2), pp. 201-225 : 213-216

Chthonius (E.) villacarrillo sp. nov.

( Figs 21–26 )

Type material. Holotype ♀, Spain, Andalusia, Jaén province, Villacarrillo , Cueva de la Morciguilla (38°5′27.87″N, 3°0′5.62″W; 701 m. a.s.l.), 24.II.2013, lgt. G.E.V. (DEUA: 20023).

Etymology. This species is dedicated to the municipal area of Villacarrillo where the type locality is found and home town of G.E.V.; noun in apposition.

Diagnosis. Weakly troglomorphic facies. No eyes or eye-spots. Chelicera with 6 setae on palm and one microseta, movable cheliceral finger with isolated subapical tooth, female with distinct spinneret. Carapace with two macrosetae on posterior margin, without preocular microsetae. Pedipalp: femur length 0.56 mm (5.5×); chela length 0.78 (5.18×); fixed finger with 19 teeth, movable finger with 12 teeth and raised lamina with 9 rounded vestigial teeth; trichobothrium ist markedly distal of eb/esb.

Description. Small hypogean species; moderate troglomorphic adaptations; integument depigmented, pale yellowish-brown; weak hispid granulation on lateral surface of ocular and posterior areas of carapace, on cheliceral palm, on base of paraxial face of pedipalpal femur, on base of movable chelal finger and on dorsodistal surface of pedipalpal hand.

Carapace ( Fig. 21 ) as broad as long, slightly constricted posteriorly, subquadrate; anterior margin ( Fig. 22 ) prominent, medially dentate and with rudimentary epistome; without eyes or eye-spots; chaetotaxy: 18 setae, without preocular microsetae, formula: 4:6:4:2:2, anteromedial seta 0.083 mm long, ocular seta 0.055 mm. Four lyrifissures in anterior and ocular areas, two in posterior area.

Pedipalpal coxa 5 setae (including 2 on manducatory process), coxa I 3 + 3 marginal microsetae, II 4 + 9–11 bipinnate coxal spines, III 5 + about 4 (coxae strongly constricted) bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Chaetotaxy of tergites I–XI: 4:4:4:4:6:6:6:6:6:4:1T2T1. Genital area with 9 setae on sternite II. Chaetotaxy of sternites III–XI: (3)8(3):(2)7(2):8:6:6:6:6:7:0. Anal cone 0+2 setae.

Chelicera ( Figs 23–24 ) with 6 setae on palm and 1 microseta laterally, seta vb very short, 0.025 mm long, microseta 0.02 mm long; seta gl 0.53 from base of movable finger. Fixed finger with 11 teeth, two distal teeth distinctly larger than others, proximally decreasing in size. Movable finger with an isolated subapical tooth (di), a large distal tooth and 7 contiguous teeth reduced in size proximally; spinneret prominent and apically rounded. Rallum with 11 blades, serrulae exterior and interior with 15 and 13 blades respectively.

Pedipalp ( Figs 25–26 ) with femoral chaetotaxy 3:6:3:5:1, four lyrifissures: one antiaxial and three paraxial. Chelal hand depressed at level of ib-isb, with a rounded hump, slightly abrupt, distad of ib-isb, and a marked ventral hollow just before base of movable chelal finger; chaetotaxy 4:5:4. Fixed finger with 18 pointed teeth and one rounded proximal tooth, all with dental canals except the two small distal ones; third distal tooth from tip modified, a little wider than others; four microtubercles at base; tip of finger with an accessory tooth (td) on antiaxial face; six teeth at level of est/it occupying 0.1 mm, distance between apices 0.015–0.018 mm. Distal half of movable finger with 12 pointed teeth with dental canals, except distal tiny one and three proximal ones, decreasing in size; proximal half of finger with slightly raised lamina with 9 rounded vestigial teeth reaching halfway between trichobothria sb and b; coupled sensilla pc between sb and b, slightly closer to sb; basal apodeme long and apically indented. Trichobothria as in fig. 25; ist markedly distal of esb, distance ist to esb 0.035 mm, distance esb to eb 0.02 mm.

Leg IV. Tactile seta ratios: tibia 0.53, basitarsus 0.43, tarsus 0.33.

Measurements and ratios. Body 1.30. Carapace 0.41/0.41 (1.0). Chelicera: palm 0.36/0.17 (2.1), movable finger 0.19. Pedipalp: femur 0.56/0.10 (5.5); patella 0.23/0.11 (2.0); chela width and depth 0.78/0.15 (5.2); hand 0.32 (2.1), length/depth (2.1); movable finger 0.45; ratio movable finger/hand 1.4; ratio femur/movable finger 1.3; ratio femur/carapace 1.4, ratio chela/carapace 1.9. Leg I: femur 0.29/0.05 (5.4); patella 0.15/0.05 (3.1); tibia 0.17/ 0.04 (4.1); tarsus 0.31/0.03 (9.2); ratio femur/patella 2.0. Leg IV: femur+patella 0.43/0.16 (2.7); tibia 0.28/0.07 (4.1); basitarsus 0.15/0.05 (3.0); telotarsus 0.30/0.03 (10.0); ratio telotarsus/basitarsus 2.0.

Remarks. Among the Iberian species with a raised lamina on movable chelal finger, with an isolated subapical tooth on the movable finger of the chelicera and only two macrosetae on the posterior margin of the carapace, C. (E.) villacarrillo differs from C. (E.) machadoi Vachon, 1940 (Algarve, Portugal) (Vachon 1940a) by the markedly distal position of trichobothrium ist with respect to esb (basal in machadoi), and in being eyeless. From the epigean species C. (E.) minutus Vachon, 1940 (Algarve, Portugal), with similar pedipalp measurements, C. (E.) villacarrillo can be distinguished by the absence of preocular microsetae and the large lamina on the proximal half of the movable chelal finger, with 9 rounded vestigial teeth reaching halfway between trichobothria sb and b, versus one preocular microseta on each side and a short proximal lamina with 6 rounded vestigial teeth reaching to level of sb in C. (E.) minutus. Chthonius (E.) morenoi Carabajal Márquez, García Carrillo & Rodríguez Fernández, 2011 (Córdoba, Spain) bears two preocular microsetae on each side and has strong troglomorphic facies with extreme pedipalp ratios (Carabajal Márquez et al. 2011), making it very different to C. (E.) villacarrillo . In addition to the three characters mentioned above, C. (E.) villacarrillo shares the absence of preocular microsetae with the hypogean species Chthonius (E.) sendrai Zaragoza, 1985 (Valencia, Spain) and Chthonius (E.) ambrosiae Carabajal Márquez, García Carrillo & Rodríguez Fernández, 2012 (Cádiz, Spain), but it is distinctly different from both of them by its markedly smaller size and robust chelal ratios: e.g. femur 0.56/0.10 (5.5) and chela 0.78/0.15 (5.18) in the new species, femur 0.86/0.12 (7.21) and chela 1.19/0.17 (7.0) in C. (E.) sendrai (Zaragoza 1985a), femur 1.19/0.15 (8.16) and chela 1.68/0.24 (6.9) in C. (E.) ambrosiae (Carabajal Márquez et al. 2012).

The type specimen of C. (E.) minutus, deposited in MNHN, has been examined and used for the above comparison (full data to be given elsewhere). Carabajal Márquez et al. (2011) identified as C. (E.) minutus a sample from Córdoba province and included the species in their key to the Andalusian Ephippiochthonius . In our opinion, this record must be discarded, in view of the distance between Algarve and Córdoba and the high endemicity displayed by subterranean Ephippiochthonius species.

Distribution. Andalusia, Spain.

Figures

FIGURES 21 – 24. Chthonius (Ephippiochthonius) villacarrillo sp. nov., female holotype. 21, carapace; 22, partial view of anterior margin of carapace; 23, left chelicera; 24, partial view of fingers of left chelicera. Scale bars (in mm): 0.1 (Figs 22 – 24), 0.2 (Fig. 21).

FIGURES 25 – 26. Chthonius (Ephippiochthonius) villacarrillo sp. nov., female holotype. 25, left pedipalp, minus chela and trochanter, dorsal view; 26, left chela, lateral view. Scale bar 0.2 mm.