Occidenchthonius serranoi, Zaragoza, Juan A., 2017

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 : 199-201

Occidenchthonius serranoi n. sp. ( Figs 311–315 )

Type locality. Portugal, Coimbra, Cabril (40°06′18″N, 07°53′07″W; 749 m a.s.l.).

Distribution. Portugal: Coimbra.

Etymology. Dedicated to Dr Artur Serrano (Faculdade de Ciências de Lisboa) for providing an important collection of samples of endogean pseudoscorpions from Portugal, some of them included in this study, and to honour his work on the Portuguese subterranean Carabidae (Coleoptera) .

Diagnosis (♀). A small, endogean Occidenchthonius species. Movable cheliceral finger without isolated subapical tooth (di) and with prominent spinneret in female, unknown for male, lyrifissure ldb present; both pairs of eyes with lens, anterior margin of carapace with 2 preocular microsetae on each side, posterior margin with 2 macrosetae; chelal hand strongly depressed at level of ib / isb, with a prominent hump distad of ib / isb and an abrupt slope between trichobothria ib / isb and eb; fixed chelal finger with 14–15 teeth; distal half of movable chelal finger with 8 pointed teeth with dental canals, basal half of movable chelal finger with 7–9 rounded, partially fused, vestigial teeth, without canals, on raised lamina; pedipalpal femur (♀) 5.1–5.3 times longer than broad, length 0.44–0.47 mm; chela (♀) 3.7–3.9 times longer than deep, length 0.61 mm; ratio movable chelal finger/chelal hand (♀) 1.3; lacking lyrifissures ma1, ma2 and hd, all other chelal lyrifissure patterns present with their standard complements.

Type material examined. ♀ holotype ( FCUL), Portugal: Coimbra, Cabril (40°06′18″N, 07°53′07″W; 749 m a.s.l.), 20.III.2007, leg. A. Serrano ; 1 ♀ paratype ( DEUA), Castelo Branco, Boxinos (40°05′23″N, 07°40′26″W; 689 m a.s.l.), 05.IV.2008, leg. A. Serrano .

Description (♀; ♂ unknown). Small, endogean species. Integument pigmented; marked hispid granulation on lateral surfaces of carapace, on cheliceral hand and on bases of chelal fingers.

Carapace ( Fig. 312 ) slightly longer than broad and weakly constricted posteriorly; medial part of anterior margin almost straight and strongly dentate ( Fig. 311 ); anterior eyes with moderately convex lens (diameter 0.350 mm), 0.0375 mm from anterior margin of carapace, posterior eyes with very weakly convex lens, 0.025 mm from anterior eyes, diameter 0.030 mm; both pairs of eyes with reflecting tapeta. Chaetotaxy: 18 setae, with 2 preocular microsetae on each side, 2 setae in posterior row, formula mm 4mm:6:4:2:2, anteromedial setae 0.10 mm long, sublateral ocular setae 0.05 mm; 4 lyrifissures anteriorly and 2 posteriorly.

Chelicera ( Figs 313, 314 ) with 6 setae and 1 lateral microseta on hand, seta vb short (0.025–0.028 mm long), microsetae 0.015–0.020 mm; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 6–9 teeth decreasing in size proximally, two distal teeth distinctly larger than others, 4–6 proximal microtubercles. Movable finger without an isolated subapical tooth (di), with 5 teeth decreasing in size proximally and 2–3 proximal microtubercles, the distal tooth larger than others; spinneret prominent in female ( Fig. 314 ), unknown for male; seta gl 0.53–0.54 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 9–10:(3)8(3):(2)7(2):8:6:6:6:6:2T1T2:0:2, lateral setae on sternite III macrosetal in size, sternite X with 2 submedial tactile setae.

Pedipalpal coxa with 5 setae (including 2 on manducatory process), distal marginal seta of disk 0.055 mm long; coxa I 3 + 3 marginal microsetae, distal marginal seta 0.055 mm long; II 4 + 6–7 bipinnate coxal spines, III 5 + 3 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Pedipalp with femoral chaetotaxy 3:6:3:5:1. Chela ( Fig. 315 ) with hand strongly depressed at level of ib / isb, with a prominent hump distad of ib / isb and an abrupt slope between trichobothria ib / isb and eb; marked hollow before base of movable finger with thicker cuticle; width shorter than depth; chaetotaxy 4:5:4, seta ph3 present; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 14–15, mostly pointed and with dental canals, except the most proximal that is low and rounded, first two distal teeth small, third tooth of normal row (mt) of fixed finger weakly modified in shape and deviated in orientation with respect to the others, dental row reaching up to level of trichobothrium sb, 3–5 proximal microtubercles; tip of finger with an accessory tooth (td) on antiaxial face; one pair of long antiaxial sensory setae (as) at the base, one level with and other markedly distad of lyrifissure fb, 0.016–0.030 mm long, distance between them 0.014–0.023 mm, fixed finger depth at the base 0.047–0.050 mm; 5 teeth at level of est / it occupying 0.1 mm, distance between successive apices 0.015–0.023 mm. Distal half of movable finger with 8 pointed teeth with dental canals that reach up to proximad of trichobothrium st, the distal one small; basal half of movable chelal finger with 7–9 rounded, partially fused, vestigial teeth, without canals, on raised lamina; dental row reaching slightly proximad of sb, 1–2 proximal microtubercles; basal apodeme long and apically indented; coupled sensilla pc level with sb. Trichobothria as in Fig. 315 ; trichobothrium ist well proximad of esb and to lyrifissure fb; distance between ib / isb and esb approximately equal to that between ib / isb and the base of the hand; distance between st and sb 1.7 times longer than that between sb and b; lacking lyrifissures ma1, ma2 and hd, all other chelal lyrifissure patterns present with their standard complements.

Measurements and ratios. Female holotype, followed, when different, by female paratype in square brackets: Body 1.32 [1.29]. Carapace 0.40/0.37 (1.1) [0.38/0.36 (1.1)]. Chelicera 0.32/0.17 (2.0) [0.34/0.17 (2.0)], movable finger 0.17 [0.18]. Pedipalp: femur 0.44/0.09 (5.1) [0.47/0.09 (5.3)], patella 0.20/0.11 (1.9) [0.20/0.11 (1.8)], chela 0.61/0.17 (3.7) [0.61/0.16 (3.9)], hand 0.27 (1.6) [0.27 (1.7)], movable finger 0.34 [0.35]; ratio movable finger/ hand 1.3, femur/movable finger 1.3 [1.4], femur/carapace 1.1 [1.2], chela/carapace 1.5 [1.6], chela/femur 1.4 [1.3].

Remarks. Occidenchthonius serranoi n. sp. does not belong to either of the recognized species-groups within the genus. Among the other three Occidenchthonius species without an isolated subapical tooth (di) on the movable cheliceral finger, differences from O. cardosoi , O. ortunoi n. sp. and O. pinai have been noted in the remarks under those species and in the key. In brief, O. serranoi n. sp. is the only species of the four with well developed eyes, absence of lyrifissure hd and stouter and shorter pedipalps.

Figures

FIGURES 311 – 315. Occidenchthonius serranoi n. sp., female holotype. 311, anterior margin of carapace, partial view; 312, carapace; 313, left chelicera; 314, fingers of left chelicera, partial view; 315, left chela, antiaxial view.