Occidenchthonius lopezi (Mahnert, 2011) Mahnert, 2011

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 : 166-167

Occidenchthonius lopezi (Mahnert, 2011) , n. comb.

(Fig. 251)

Chthonius (Ephippiochthonius) lopezi Mahnert 2011a: 28 –29, figs 1–4.

Type locality. Spain, Canary Islands, Santa Cruz de Tenerife province, Tenerife Island, Monte del Agua , Barranco de los Cochinos (28°21′05″N, 16°49′01″W; 259 m a.s.l.) .

Distribution. Spain: Canary Islands.

Diagnosis (♂ ♀). A small, hypogean Occidenchthonius species of the machadoi -group. Movable cheliceral finger with isolated subapical tooth (di) and with prominent spinneret in female, absent in male, lyrifissure ldb present; without eyes or eye-spots, anterior margin of carapace with 1–3 preocular microsetae on each side, posterior margin with 2 medial macrosetae and 2 lateral microsetae; chelal hand distinctly depressed at level of ib / isb, with short and prominent hump distad of ib / isb and moderate slope between trichobothria ib / isb and eb, chaetotaxy 4:4:4; fixed chelal finger with 15–17 teeth; distal half of movable chelal finger with 10–12 pointed teeth with dental canals, basal half of movable chelal finger with 7–9 rounded, partially fused, vestigial teeth, without canals, on weakly raised lamina; pedipalpal femur (♂ ♀) 4.9–5.5 times longer than broad, length (♂) 0.41–0.42 mm, (♀) 0.48–0.50 mm; chela (♂ ♀) 5.0–5.5 times longer than deep, length (♂) 0.58–0.61 mm, (♀) 0.69 mm; ratio movable chelal finger/chelal hand (♂ ♀) 1.5–1.6; lacking lyrifissures ma1 and ma2, all other chelal lyrifissure patterns present with their standard complements.

Type material examined. Spain, Canary Islands, Santa Cruz de Tenerife province, Tenerife Island : 1 ♂ paratype ( MHNG) , 1 ♂ paratype (DZUL), Monte del Agua, Barranco de los Cochinos (28°21′05″N, 16°49′01″W; 259 m a.s.l.), 30.XI.2006, leg. P. Oromí & H. López; 1 ♂ paratype, Anaga, Degollada de Bicora (28°32′43″N, 16°13′45″W; 732 m a.s.l.), (DZUL), 08.XII.2002, leg. H. Contreras.

Description (♂ ♀). Small, hypogean species of MSS. Integument weakly depigmented; weak hispid granulation on lateral surfaces of carapace, on cheliceral hand and on bases of chelal fingers.

Carapace as long as or slightly longer than broad and weakly constricted posteriorly; medial part of anterior margin distinctly prominent, without a well-defined epistome, and strongly dentate; without eyes or eye-spots. Chaetotaxy: 18 macrosetae, with 1–3 preocular microsetae on each side (one male examined 3+3, other 2+3), posterior margin with 2 medial macrosetae and 2 lateral microsetae, setal formula (preocular microsetae omitted): 4:6:4:2:m 2m, anteromedial setae 0.09–0.10 mm long, sublateral ocular setae 0.04–0.05 mm, posteromedial macrosetae 0.05 mm, posterolateral microsetae 0.025; 4 lyrifissures anteriorly and 2 posteriorly.

Cheliceral hand with 6 (rarely 7) setae and 1–3 lateral microsetae, seta vb very short (0.018–0.020 mm long), microsetae 0.015–0.016 mm; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 8–10 teeth decreasing in size proximally. Movable finger with an isolated subapical tooth (di), with 5–9 teeth decreasing in size proximally; spinneret small in female, absent in male; seta gl 0.56–0.59 from base of movable finger. Rallum with 11 blades. Serrula exterior with 14–15 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 (0.20 and 0.24 mm long, respectively). Chaetotaxy of sternites 10:(3)8–10(3):(2)7–8(2):6–8:6–7:6:6:6:2T1T2:0:2, lateral setae on sternite III macrosetal in size, sternite X with 2 submedial tactile setae (0.15 mm long); in addition, genital notch of male flanked by 5–7 setae on each side and 3–4+3–4 internal glandular setae.

Pedipalpal coxa with 5 setae (including 2 on manducatory process), distal marginal seta of disk 0.06–0.07 mm long; coxa I 3 + 3 marginal microsetae, distal marginal seta 0.05 mm long; II 4 + 5–8 bipinnate coxal spines, III 5 + 3–5 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Pedipalp with femoral chaetotaxy 3:6:3:5:1. Chela (Fig. 251) with hand distinctly depressed at level of ib / isb, with short and prominent hump distad of ib / isb and moderate slope between trichobothria ib / isb and eb; marked hollow before base of movable finger with thicker cuticle; width shorter than depth, maximum width proximad of ib / isb; chaetotaxy 4:4:4, seta ph3 present, seta ih5 absent, seta dh3 removed to the intermediate setal row; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 15–17 mostly pointed teeth and with dental canals, 1–2 most proximal teeth distinctly reduced in size and with or without dental canals, first two distal teeth small, third tooth of normal row (mt) of fixed finger distinctly modified in shape and deviated in orientation with respect to the others, dental row reaching up to slightly distad or proximad of trichobothrium sb, about 10 proximal microtubercles; tip of finger with an accessory tooth (td) on antiaxial face; tip of fixed chelal finger of male with a weak hollow on paraxial face, without subdistal protuberance (sp); one pair of long antiaxial sensory setae (as) at the base, one level with and other distinctly distad of lyrifissure fb, 0.030–0.033 mm long, distance between them 0.020–0.025 mm, fixed finger depth at the base 0.043–0.045 mm; 6 teeth at level of est / it occupying 0.1 mm, distance between successive apices 0.016–0.019 mm. Distal half of movable finger with 10–12 pointed teeth with dental canals that reach up to halfway between trichobothria st and sb, 1–2 proximal teeth more reduced in size, 1–2 distal teeth tiny or small; basal half of movable chelal finger with 7–9 rounded, partially fused, vestigial teeth, without canals, on weakly raised lamina; dental row reaching proximad of sb, some very weakly microtubercles at base; basal apodeme long and apically indented; coupled sensilla pc between sb and b, slightly closer to b. Trichobothria as in Fig. 251; trichobothrium ist distinctly distad of esb and proximad of lyrifissure fb; trichobothria eb -esb -ist almost in a straight line; distance between ib / isb and base of hand 1.1 times longer than that between ib / isb and esb; distance between st and sb 1.5 times longer than that between sb and b; lacking lyrifissures ma1 and ma2, all other chelal lyrifissure patterns present with their standard complements.

Measurements and ratios. Holotype and paratypes, measurements of males followed by females in square brackets, ratios ♂ ♀ combined in brackets: Body 0.82–1.10. Carapace 0.32–0.35/0.30–0.33 [0.40/0.37] (1.0–1.1). Pedipalp: femur 0.41–0.42/0.08 [0.48–0.50/0.10–0.11] (4.9–5.5), patella 0.18–0.19/0.09 [0.21–0.22/0.10–0.11] (2.0–2.1), chela 0.58–0.61/0.11–0.12 [0.69/0.13-0.14] (5.0–5.5), hand 0.24–0.25 [0.28] (2.0–2.3), movable finger 0.34–0.37 [0.41–0.42]; ratio movable finger/hand 1.5–1.6, femur/movable finger 1.1–1.2, femur/carapace 1.2–1.3, chela/carapace 1.7–1.8, chela/femur 1.4–1.5.

Remarks. Occidenchthonius lopezi (Mahnert, 2011) is an anophthalmic species of the machadoi -group, endemic to the Canarian island of Tenerife. It shares with O. tenerifae (Mahnert, 2011) the presence of 4 setae in the posterior row of the carapace and the absence of eyes. The differences between them are mainly morphometric, with O. lopezi being markedly smaller [chela (♀) 5.0–5.5 times longer than deep, length 0.69 mm in O. lopezi versus chela (♀) 6.1 times longer than deep, length 1.08 mm in O. tenerifae ], as compared in the key. The above description incorporates in part that of Mahnert (2011a).