Occidenchthonius canariensis Beier 1965, n. comb.
Creators: name: Zaragoza, Juan A.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Occidenchthonius
Occidenchthonius canariensis

description: Occidenchthonius canariensis (Beier, 1965), n. comb.
(Fig. 228)
Chthonius (Ephippiochthonius) machadoi canariensis Beier 1965: 375 –377, fig. 1. Chthonius (Ephippiochthonius) canariensis: Mahnert 2011a: 41.
Type locality. Spain, Canary Islands, Santa Cruz de Tenerife province, Tenerife Island, Erjos (28°19′44″N, 16°48′19″W; 989 m a.s.l.).
Distribution. Spain: Canary Islands.
Diagnosis (♂ ♀). A small, epigean 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; anterior pair of eyes with strongly convex lens, more moderately in posterior eyes; anterior margin of carapace with 1–3 preocular microsetae on each side, posterior margin with 2 macrosetae; chelal hand distinctly depressed at level of ib / isb, with distinct, short and weakly conical, hump distad of ib / isb and an abrupt slope between trichobothria ib / isb and eb, chaetotaxy 4:4:4; fixed chelal finger with 17–18 teeth; distal half of movable chelal finger with 9–11 pointed teeth with dental canals, basal half of movable chelal finger with 9 rounded, partially fused, vestigial teeth, without canals, on raised lamina; pedipalpal femur (♂) 5.1–5.3, (♀) 5.2 times longer than broad, length (♂) 0.41–0.42 mm, (♀) 0.44–0.48 mm; chela (♂) 5.1, (♀) 4.6–4.9 times longer than deep, length (♂) 0.57–0.59 mm, (♀) 0.61–0.62 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.
Non-type material examined. Spain, Canary Islands, Santa Cruz de Tenerife province, Tenerife Island: 1 ♂ (MHNG), Monte del Agua, Barranco de los Cochinos (28°21′05″N, 16°49′01″W; 261 m a.s.l.), from MSS, 30.XI.2006, leg. P. Oromí & H. López, det. V. Mahnert; 1 ♂, 1 ♀ (MHNG), El Tanque, Ruigómez (28°20′25″N, 16°47′28″W; 875 m a.s.l.), sieved leaf litter, 12.III.1983, leg. C. Besuchet, det. V. Mahnert; 1 ♀ (MHNG), Monte Los Silos, Barranco Picón (28°22′05″N, 16°49′06″W; 128 m a.s.l.), 16.I.1986, leg. A. Aguilar, det. V. Mahnert.
Description (♂ ♀). Small, epigean species. Integument pigmented; marked hispid granulation on lateral surfaces of carapace, on cheliceral hand and on bases of chelal fingers.
Carapace slightly longer than broad and weakly constricted posteriorly; medial part of anterior margin weakly prominent, without a well-defined epistome, and strongly dentate; anterior eyes with strongly convex lens (diameter 0.028–0.038 mm) and reflecting tapetum, 0.035–0.038 mm from anterior margin of carapace, posterior eyes with moderately convex lens (diameter 0.030–0.038 mm), 0.025 mm from anterior eyes. Chaetotaxy: 18 setae, usually with 2 preocular microsetae on each side (rarely 1 or 3), 2 setae in posterior row, macrosetal formula 4:6:4:2:2, anteromedial setae 0.08–0.11 mm long, sublateral ocular setae 0.04–0.06 mm; 4 lyrifissures anteriorly and 2 posteriorly.
Cheliceral hand with 6 setae and 3–5 lateral microsetae, seta vb short (length 0.018–0.025 mm), microsetae 0.010–0.013 mm; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 8–9 teeth decreasing in size proximally, 1–2 distal teeth distinctly larger than others, 2–3 proximal microtubercles. Movable finger with an isolated subapical tooth (di), with 4–7 teeth decreasing in size proximally and 0–2 proximal microtubercles, the distal tooth larger than others; spinneret well prominent and apically rounded in female, absent in male; seta gl 0.55–0.61 from base of movable finger. Rallum with 11 blades. Serrula exterior with 14 blades, serrula interior 10–12 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 (0.18–0.20 and 0.26–0.30 mm long, respectively). Chaetotaxy of sternites 10:(3)8(3):(2)7–8(2):7– 8:6:6:6:6:2T1T2:0:2, lateral setae on sternite III macrosetal in size, sternite X with 2 submedial tactile setae (0.16– 0.19 mm long); in addition, genital notch of male flanked by 6–7 setae on each side and 4+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 0.06–0.07 mm long; II 4 + 5–7 bipinnate coxal spines, III 5 + 3–4 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.
Pedipalp with femoral chaetotaxy 3:6:3:5:1. Chela (Fig. 228) with hand distinctly depressed at level of ib / isb, with distinct, short and weakly conical, 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, maximum width slightly proximad of ib / isb; chaetotaxy 4:4:4, seta ph3 present, seta ih5 absent; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 17–18 mostly pointed teeth and with dental canals, the most proximal tooth usually rounded, first two distal teeth small, third tooth of normal row (mt) of fixed finger weakly modified in shape and distinctly deviated in orientation with respect to the others, dental row reaching to level trichobothrium sb or just behind it, 4–9 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, 0.020–0.028 mm long, distance between them 0.019–0.025 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 0.015–0.020 mm. Distal half of movable finger with 9–11 pointed teeth with dental canals that reach up to proximad of halfway between trichobothria st and sb, the distal tooth tiny, the subdistal one small; basal half of movable chelal finger with 9 rounded, partially fused, vestigial teeth, without canals, on weakly raised lamina; dental row reaching slightly proximad of sb, 5–6 proximal microtubercles; basal apodeme long and apically indented; coupled sensilla pc slightly proximad of sb. Trichobothria as in Fig. 228; trichobothrium ist level with or slightly proximad of esb and well proximad of lyrifissure fb; distance between ib / isb and base of hand 1.1–1.2 times longer than that between ib / isb and esb; distance between st and sb 2.0–2.2 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. Males, followed, when different, by females in square brackets: Body 1.10–1.21 [1.22–1.25]. Carapace 0.37/0.34–0.35 (1.1) [0.39–0.40/0.35–0.39 (1.0–1.1)]. Chelicera 0.28–0.30/0.14–0.15 (2.0) [0.30–0.33/0.15 (2.0–2.1)], movable finger 0.14–0.15 [0.15–0.17]. Pedipalp: femur 0.41–0.42/0.08 (5.1–5.3) [0.44–0.48/0.09 (5.2)], patella 0.19/0.10 (1.9) [0.20–0.21/0.10–0.11 (2.0), chela 0.57–0.59/0.11 (5.1) [0.61–0.62/ 0.12–0.14 (4.6–4.9), hand 0.22–0.23 (2.0) [0.24–0.25 (1.9–2.0)], movable finger 0.35 [0.36–0.38]; ratio movable finger/hand 1.5–1.6, femur/movable finger 1.2 [1.2–1.3], femur/carapace 1.1 [1.1–1.2], chela/carapace 1.5–1.6 [1.6], chela/femur 1.3–1.4.
Remarks. Occidenchthonius canariensis (Beier, 1965) belongs to the machadoi -group. It is an eyed, epigean species, endemic to the Canary Islands, being found on all the islands except Fuerteventura. It shares with O. machadoi (Vachon, 1940) the presence of well developed eyes with convex lenses and having trichobothrium ist distinctly proximad of esb. O. canariensis differs from O. machadoi in having a more slender chela, the fixed chelal finger with 20–21 teeth (versus 12–16) and the movable with 9–10 teeth (versus 7). The above description incorporates in part those of Beier (1965) and Mahnert (2011a).
description: Published as part of 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), pp. 1-221 in Zootaxa 4246 (1) on pages 139-140, DOI: 10.5281/zenodo.437611