Occidenchthonius beieri, 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 : 134-137

Occidenchthonius beieri n. sp. ( Figs 222–227 )

Chthonius (Ephippiochthonius) dubius (not Mahnert, 1993): Mahnert 2011a: 41 –42 (misidentification: see Remarks below).

Type locality. Spain, Canary Islands, Las Palmas province, Gran Canaria Island, Los Majaletes (27°57′17″N, 15°30′44″W; 1274 m a.s.l.) .

Distribution. Spain: Canary Islands, Gran Canaria Island.

Etymology. Dedicated to the memory of Prof. Max Beier (1903–1979), to honour his remarkable contribution to the knowledge of the pseudoscorpions around the World and particularly those of the Iberian Peninsula and the Canary Islands.

Diagnosis (♂ ♀). A small, microphthalmic, 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; anterior pair of eyes with lens, posterior eyes absent, anterior margin of carapace medially prominent, with 1–2 preocular microsetae on each side, posterior margin with 2 macrosetae; chelal hand distinctly depressed at level of ib / isb, with a hump distad of ib / isb and moderate slope between trichobothria ib / isb and eb, chaetotaxy 4:4:4; fixed chelal finger with 16–17 teeth; distal half of movable chelal finger with 9–10 pointed teeth with dental canals, basal half of movable chelal finger with 8–10 rounded, partially fused, vestigial teeth, without canals, on raised lamina; pedipalpal femur (♂) 6.0–6.1, (♀) 5.9 times longer than broad, length (♂) 0.53 mm, (♀) 0.53–0.58 mm; chela (♂) 5.7–5.8, (♀) 5.0–5.2 times longer than deep, length (♂) 0.71–0.72 mm, (♀) 0.75–0.76 mm; ratio movable chelal finger/chelal hand (♂) 1.5–1.6, (♀) 1.4–1.5; lacking lyrifissures ma1 and ma2, all other chelal lyrifissure patterns present with their standard complements.

Type material examined. ♂ holotype, 1 ♂, 4 ♀, paratypes ( MHNG), Spain, Canary Islands, Las Palmas province, Gran Canaria Island, Los Majaletes (27°57′17″N, 15°30′44″W; 1274 m a.s.l.), 03.V.2006, leg. H. López .

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

Carapace ( Fig. 223 ) 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 small with low convex lens (diameter 0.040 mm) and reflecting tapetum, 0.035 mm from anterior margin of carapace, posterior eyes absent. Chaetotaxy: 18 setae, usually with 2 preocular microsetae on each side (one male with 1 on one side), 2 setae in posterior row, usual formula mm 4mm:6:4:2:2, anteromedial setae 0.11–0.14 mm long, sublateral ocular setae 0.04–0.08 mm; 4 lyrifissures anteriorly and 2 posteriorly.

Chelicera ( Figs 224, 225, 227 ) with 6 setae and 2–4 lateral microsetae on hand, seta vb short (length 0.020– 0.030 mm), microsetae 0.010–0.025 mm; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 7–9 teeth decreasing in size proximally, two distal teeth distinctly larger than others, 2–3 proximal microtubercles. Movable finger with an isolated subapical tooth (di), with 5–7 teeth decreasing in size proximally and 1–3 proximal microtubercles, the distal tooth larger than others; spinneret prominent and apically rounded in female ( Fig. 227 ), almost absent in male ( Fig. 225 ); seta gl 0.54–0.61 from base of movable finger. Rallum with 11 blades. Serrula exterior with 15 blades, serrula interior 12–13 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 (0.24 and 0.29–0.30 mm long, respectively). Chaetotaxy of sternites 10:(3)7–8(3):(2)6–7(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 (0.20 mm long); in addition, genital notch of male flanked by 5–7 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 0.07–0.08 mm long; coxa I 3 + 3 marginal microsetae, distal marginal seta 0.04–0.06 mm long; II 4 + 6–11 bipinnate coxal spines, III 5 + 4–6 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Pedipalp with femoral chaetotaxy 3:6:3:5:1. Chela ( Fig. 226 ) with hand distinctly depressed at level of ib / isb, with a 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 3– 4:4:4 (lacks seta ph4 on one chela, present on the other), seta ph3 present, seta ih5 absent; distal end of hand and bases of chelal fingers with sclerotized condylar complex. Fixed finger with 16–17 mostly pointed teeth and with dental canals, 1–2 most proximal teeth reduced in size, 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 proximad of trichobothrium sb, 7–15 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 markedly distad of lyrifissure fb, 0.035–0.050 mm long, distance between them 0.020–0.033 mm, fixed finger depth at the base 0.045–0.050 mm; 4–5 teeth at level of est / it occupying 0.1 mm, distance between successive apices 0.020–0.025 mm. Distal half of movable finger with 9–10 pointed teeth with dental canals that reach up to proximad of trichobothrium st, the distal tooth tiny (rarely absent) and on low protuberance, the subdistal one tiny or small; basal half of movable chelal finger with 8–10 rounded, partially fused, vestigial teeth, without canals, on weakly raised lamina; dental row reaching level with or slightly proximad of sb, 5–7 proximal microtubercles; basal apodeme long and apically indented; coupled sensilla pc slightly proximad of sb. Trichobothria as in Fig. 226 ; trichobothrium ist slightly distad of esb and well proximad of lyrifissure fb; trichobothria eb -esb -ist in a straight line; distance between ib / isb and esb approximately equal to that between ib / isb and the base of the hand; distance between st and sb 1.8–2.1 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. Male holotype, followed, when different, by male paratype in square brackets: Body 1.12 [1.07]. Carapace 0.39/0.35 (1.1) [0.41/0.36]. Chelicera 0.34–0.15 (2.2) [0.33–0.15], movable finger 0.16. Pedipalp: femur 0.53/0.09 (6.0) [(6.1)], patella 0.23/0.11 (2.1) [0.23/0.10 (2.2)], chela 0.72/0.13 (5.8) [0.71/0.13 (5.7)], hand 0.29 (2.3) [0.28 (2.2)], movable finger 0.43 [0.44]; ratio movable finger/hand 1.5 [1.6], femur/movable finger 1.2, femur/carapace 1.3, chela/carapace 1.8, chela/femur 1.4 [1.3]. Female paratypes: Body 1.28–1.45. Carapace 0.42–0.43/0.38–0.39 (1.1). Chelicera 0.35–0.37/0.17–0.18 (2.1), movable finger 0.17–0.18. Pedipalp: femur 0.53–0.58/0.09–0.10 (5.9), patella 0.24–0.25/0.11–0.12 (2.1), chela 0.75–0.76/0.14–0.15 (5.0–5.2), hand 0.30–0.32 (2.1), movable finger 0.45; ratio movable finger/hand 1.4 [1.5], femur/movable finger 1.2–1.3, femur/ carapace 1.2–1.4, chela/carapace 1.7–1.8, chela/femur 1.3–1.4.

Remarks. A sample of the specimens from Gran Canaria, Los Majaletes assigned to O. dubius by Mahnert (2011a) has been re-examined and found to belong to a new species, here named Occidenchthonius beieri n. sp., which is endemic to Gran Canaria Island. Contrary to O. dubius , O. beieri n. sp. belongs to the machadoi -group. O. beieri n. sp. shares with O. tamaran (Mahnert, 2011) , another endemic species from Gran Canaria Island, the presence of 2 setae in the posterior row of the carapace. Differences between the two species are the prominent medial margin of the carapace, the absence of posterior eyes and a cheliceral spinneret in male of O. beieri n. sp., as opposed to the straight margin, presence of posterior eye-spots and prominent cheliceral spinneret in male of O. tamaran . Morphometric differences are given in the key. The presence of O. dubius on Gran Canaria Island is excluded here and all previous records of this species from that island are reassigned to O. beieri n. sp. The distribution range of O. dubius is thus limited to Tenerife Island.

Figures

FIGURES 222 – 227. Occidenchthonius beieri n. sp., male holotype (222 – 226) and female paratype (227). 222, anterior margin of carapace, partial view; 223, carapace; 224, left chelicera; 225, fingers of left chelicera, partial view; 226, left chela, antiaxial view; 227, movable finger of left chelicera, partial view.