Occidenchthonius machadoi Vachon 1940, n. comb.
Creators: name: Zaragoza, Juan A.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Occidenchthonius
Occidenchthonius machadoi

description: Occidenchthonius machadoi (Vachon, 1940), n. comb.
(Figs 10‒11, 262–265)
Chthonius (Ephippiochthonius) machadoi Vachon 1940: 11 –13, figs 1–6. Chthonius (Ephippiochthonius) machadoi machadoi: Zaragoza 2007: 17.
Type localities. Portugal, Algarve region, Faro district: Albufeira, near Paderne, Algaräo da Ribeira de Alte; Cêrro de Cabeça Gorda, Loulé, Algaräo do Paulino; Aljezur, Furna da Seiceira.
Distribution. Portugal: Algarve region. Spain: Andalusia, Asturias, Galicia regions.
Diagnosis (♂ ♀). A small epigean or endogean 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; at least, anterior pair of eyes with lens, anterior margin of carapace with 1–2 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, chaetotaxy 4:4:4; fixed chelal finger with 12–18 teeth; distal half of movable chelal finger with 7–9 pointed teeth with dental canals, basal half of movable chelal finger with 8–11 rounded, partially fused, vestigial teeth, without canals, on raised lamina; pedipalpal femur (♂) 5.8, (♀) 4.8–6.1 times longer than broad, length (♂) 0.46 mm, (♀) 0.50–0.73 mm; chela (♂) 4.5, (♀) 3.8–4.7 times longer than deep, length (♂) 0.63 mm, (♀) 0.68–1.00 mm; ratio movable chelal finger/chelal hand (♂) 1.3, (♀) 1.3–1.4; lacking lyrifissures ma1 and ma2, all other chelal lyrifissure patterns present, most with their standard complements.
Type material examined. 1 ♀ syntype (MNHN; mounted on 2 slides), Portugal, Algarve region, Faro district: Cêrro de Cabeça Gorda, Loulé, Algaräo do Paulino, leg. A. de B. Machado; 1 ♂ syntype (MNHN; mounted on 3 slides), Aljezur, Furna da Seiceira, leg. A. de B. Machado.
Non-type material examined. Portugal, Algarve region, Faro district, 1 ♀, Cachopos (37°14′49″N, 07°44′14″W; 485 m a.s.l.), 08.I.2004, leg. A. Serrano (FCUL). Spain, Andalusia region: Córdoba province, 2 ♀, Priego de Córdoba, Cueva de la Solana (37°30′35″N, 04°13′13″W; 894 m a.s.l.), 22.VIII.2010, leg. G.E.S.P. (CECOUAL, DEUA); Sevilla province, 1 ♀, Alanís, Sima del Paro (38°01′05″N, 05°39′52″W; 607 m a.s.l.), 08.VI.2013, leg. C. D.P. (CECOUAL).
Description (♂ ♀). Small, epigean species, also found in endogean habitats; 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 straight or slightly prominent, strongly dentate; anterior eyes with moderately convex lens (diameter 0.03 5– 0.050 mm), 0.040–0.050 mm from anterior margin of carapace, posterior eyes with weakly convex lens, 0.045–0.055 mm from anterior eyes, diameter 0.035–0.045 mm, at least the anterior pair of eyes with reflecting tapetum. Chaetotaxy: 18 setae, with 1–2 preocular microsetae on each side, 2 setae in posterior row, macrosetal formula 4:6:4:2:2, anteromedial setae 0.10–0.11 mm long, sublateral ocular setae 0.05–0.08 mm; 4 lyrifissures anteriorly and 2 posteriorly.
Chelicera (Figs 262, 263, 265) with 6 setae and 1–2 lateral microsetae on hand, seta vb short (0.025–0.045 mm long), microsetae 0.013–0.023 mm; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 7–11 teeth decreasing in size proximally, two distal teeth distinctly larger than others, 2–4 proximal microtubercles. Movable finger with an isolated subapical tooth (di), with 5–9 teeth decreasing in size proximally and 2 proximal microtubercles, the distal tooth larger than others; spinneret prominent in female (Fig. 265), very strongly reduced, almost absent, in male (Fig. 263); seta gl 0.54–0.59 from base of movable finger. Rallum with 11 blades. Serrula exterior with 14–15 blades, serrula interior 11–12 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, tactile seta XI 0.25–0.34 mm long. Chaetotaxy of sternites 9–10:(3)7–8(3):(2)7(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 (0.18–0.20 mm long).
Pedipalpal coxa with 5 setae (including 2 on manducatory process), distal marginal seta of disk 0.070–0.095 mm long; coxa I 3 + 3 marginal microsetae, distal marginal seta 0.040–0.060 mm long; II 4 + 6–15 bipinnate coxal spines, III 5 + 3–9 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.
Pedipalp with femoral chaetotaxy 3:6:3:5–6:1. Chela (Figs 10, 11, 264) 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 slightly shorter than depth; chaetotaxy 4:4:4 (one female syntype and one female from Córdoba 4:3:4 on one chela), seta ph3 present and seta ih5 absent; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 12–18 teeth, mostly pointed and with dental canals, 1–2 more proximal teeth slightly reduced in size, first two distal teeth small, third tooth of normal row (mt) of fixed finger weakly or distinctly modified in shape and deviated in orientation with respect to the others, dental row reaching up to level of trichobothrium sb, 5–9 proximal microtubercles; tip of finger with an accessory tooth (td) on antiaxial face; one pair of short antiaxial sensory setae (as) at the base, one level with and other markedly distad or on either side of lyrifissure fb, 0.025–0.060 mm long, distance between them 0.025–0.065 mm, fixed finger depth at the base 0.055–0.065 mm; 4–5 teeth at level of est / it occupying 0.1 mm, distance between successive apices 0.023–0.028 mm. Distal half of movable finger with 7–9 pointed teeth with dental canals that reach up to level or slightly proximad of trichobothrium st, the distal one tiny or small; basal half of movable chelal finger with 8–11 rounded, partially fused, vestigial teeth, without canals, on raised lamina; dental row reaching level of sb; basal apodeme long and apically indented; coupled sensilla pc level with or slightly proximad of sb. Trichobothria as in Figs. 10–11, 264; trichobothrium ist distinctly proximad of esb and to lyrifissure fb; distance between ib / isb and base of hand 1.1–1.3 times longer than that between ib / isb and esb; distance between st and sb 1.5–2.0 times longer than that between sb and b; lacking lyrifissures ma1 and ma2, all other chelal lyrifissure patterns present with their standard complements, except that the female from Cachopos lacks lyrifissure hp.
Measurements and ratios. Female syntype, followed, when different, by male syntype in square brackets: Body 1.50 [1.30]. Pedipalp: femur 0.61/0.11 (5.5) [0.46/0.08 (5.8)], patella 0.22/0.13 (1.7) [0.20/0.11 (1.8)], chela 0.85/0.22 (3.9) [0.63/0.14 (4.5)], hand 0.37 (1.7) [0.27 (1.9)], movable finger 0.50 [0.35]; ratio movable finger/ hand 1.4 [1.3], femur/movable finger 1.2 [1.3], chela/femur 1.4. Female from Cachopos, Portugal: Body 1.50. Carapace 0.42/0.38 (1.1). Chelicera 0.33/0.16 (2.0), movable finger 0.18. Pedipalp: femur 0.50/0.09 (5.4), patella 0.20/0.12 (1.7), chela 0.68/0.18 (3.8), hand 0.30 (1.7), movable finger 0.38; ratio movable finger/hand 1.3, femur/ movable finger 1.3, femur/carapace 1.2, chela/carapace 1.6, chela/femur 1.4. Females from Córdoba and Sevilla, Spain: Body 1.44–1.92. Carapace 0.43–0.56/0.40–0.51 (1.1). Chelicera 0.35–0.45/0.19–0.23 (1.9–2.1), movable finger 0.19–0.25. Pedipalp: femur 0.50–0.73/0.10–0.12 (4.8–6.1), patella 0.24–0.32/0.12–0.16 (2.0), chela 0.70– 1.00/0.17–0.24 (4.2–4.7), hand 0.30–0.44 (1.8–1.9), movable finger 0.40–0.58; ratio movable finger/hand 1.3–1.4, femur/movable finger 1.2–1.3, femur/carapace 1.2–1.3, chela/carapace 1.6–1.8, chela/femur 1.4.
Remarks. Occidenchthonius machadoi is the only species of the machadoi -group found outside the Canary Islands. It resembles O. canariensis in having both pairs of eyes with convex lens, two setae on the posterior margin of the carapace, a stout and small pedipalp, and trichobothrium ist distinctly proximad of esb. Differences between the two species are given in the remarks under O. canariensis and in the key. A more detailed comparison is given by Mahnert (2011a). The female from Cachopos (Portugal) lacks lyrifissure hp on both chelae, but its other characteristics fit well with O. machadoi. More specimens from this Portuguese locality will need to be checked to determine whether intraspecific variation occurs in this population. The above description incorporates in part that of Vachon (1940).
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 167-170, DOI: 10.5281/zenodo.437611