Occidenchthonius tenerifae Mahnert 2011, n. comb.

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

(Fig. 318)

Chthonius (Ephippiochthonius) tenerifae Mahnert 2011a: 31 –32, figs 10–12.

Type locality. Spain, Canary Islands, Santa Cruz de Tenerife province, Tenerife Island, Monte del Agua, Buena Vista del Norte, Barranco de los Cochinos (28°21′05″N, 16°49′01″W; 261 m a.s.l.).

Distribution. Spain: Canary Islands.

Diagnosis ( ♀ ). An eyeless hypogean, medium-sized Occidenchthonius species of the machadoi -group. Movable cheliceral finger with isolated subapical tooth (di) and with prominent spinneret in female, unknown for male, lyrifissure ldb present; without eyes or eye-spots, anterior margin of carapace with 2 preocular microsetae on each side, posterior margin with 2 medial macrosetae and 2 lateral microsetae; chelal hand weakly depressed at level of ib / isb, with a short hump distad of ib / isb and moderate slope between trichobothria ib / isb and eb; chaetotaxy 4:4:4; fixed chelal finger with 21 teeth; distal half of movable chelal finger with 14 pointed teeth with dental canals, basal half of movable chelal finger with 10 rounded, partially fused, vestigial teeth, without canals, on raised lamina; pedipalpal femur (♀) 5.7 times longer than broad, length 0.73 mm; chela (♀) 6.1 times longer than deep, length 1.08 mm; ratio movable chelal finger/chelal hand (♀) 1.6; lacking lyrifissures ma1 and ma2, all other chelal lyrifissure patterns present with their standard complements.

Type material examined. ♀ holotype (DZUL), Spain, Canary Islands, Santa Cruz de Tenerife province, Tenerife Island, Monte del Agua, Buena Vista del Norte, Barranco de los Cochinos (28°21′05″N, 16°49′01″W; 261 m a.s.l.), MSS, 21.I.2003, leg. H. Contreras.

Description ( ♀; ♂ unknown). Medium-sized, eyeless, hypogean species of MSS. Integument depigmented; 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; without eyes or eye-spots. Chaetotaxy: 19 macrosetae, with 2 preocular microsetae on each side, posterior margin with 2 medial macrosetae and 2 lateral microsetae, setal formula mm 4mm:6:4:3:m 2m, anteromedial setae 0.15 mm long, sublateral ocular setae 0.14 mm. Cheliceral hand with 6 setae and 2–4 lateral microsetae, seta vb short (0.030 mm long), microsetae 0.020–0.025 mm; hand with 5 dorsal and 1 ventral lyrifissure, lyrifissure ldb present. Fixed finger with 14 teeth decreasing in size proximally. Movable finger with an isolated subapical tooth (di), with 8 teeth decreasing in size proximally; spinneret prominent in female, unknown for male. Rallum with 11 blades. Serrula exterior with 18 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 0.31 mm long. Chaetotaxy of sternites 10:(3)9(3):(2)6(2):8:6:6:6:6:2T1T2:0:2, lateral setae on sternite III macrosetal in size, sternite X with 2 submedial tactile setae (0.21 mm long).

Pedipalpal coxa with 5 setae (including 2 on manducatory process), distal marginal seta of disk 0.09 mm long; coxa I 3 + 3 marginal microsetae, distal marginal seta 0.07 mm long; II 4 + 8–9 bipinnate coxal spines, III 5 + 6–7 bipinnate coxal spines and IV 6; intercoxal tubercle bisetose.

Pedipalp with femoral chaetotaxy 3:6:3:6:1. Chela (Fig. 318) with hand weakly depressed at level of ib / isb, with a short hump distad of ib / isb and moderate slope between trichobothria ib / isb and eb; marked hollow before base of movable finger with thicker cuticle; maximum width 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 21 mostly pointed teeth and with dental canals, 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 distad of halfway between trichobothria sb and b, 14 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, 0.045–0.050 mm long, distance between them 0.048 mm, fixed finger depth at the base 0.068 mm; 4 teeth at level of est / it occupying 0.1 mm, distance between successive apices 0.025–0.030 mm. Distal half of movable finger with 14 pointed teeth with dental canals that reach up to slightly proximad of halfway between trichobothria st and sb, the distal tooth tiny, the subdistal one small; basal half of movable chelal finger with 10 rounded, partially fused, vestigial teeth, without canals, on raised lamina; dental row reaching halfway between trichobothria sb and b, 4 proximal microtubercles; basal apodeme long and apically indented; coupled sensilla pc halfway between trichobothria sb and b. Trichobothria as in Fig. 318; trichobothrium ist distinctly proximad of esb and well proximad of 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 and ma2, all other chelal lyrifissure patterns present with their standard complements.

Measurements and ratios. Female holotype: Body 1.64. Carapace 0.56/0.50 (1.1). Pedipalp: femur 0.73/0.14 (5.7), patella 0.31/0.14 (2.3), chela 1.08/0.18 (6.1), hand 0.41 (2.3), movable finger 0.67; ratio movable finger/hand 1.6, femur/movable finger 1.1, femur/carapace 1.3, chela/carapace 1.9, chela/femur 1.5.

Remarks. Occidenchthonius tenerifae is an anophthalmic species endemic to Tenerife Island. Within the machadoi -group, it resembles O. lopezi in having 4 setae in the posterior row of the carapace and lacking eyes. Differences between the two species are mainly morphometric, with O. tenerifae being markedly larger, as compared in the key. The above description incorporates in part that of Mahnert (2011a).