Vachoniolus batinahensis, Lowe, 2010

Lowe, Graeme, 2010, The genus Vachoniolus (Scorpiones: Buthidae) in Oman, Euscorpius 100 (100), pp. 1-37 : 3-10

Vachoniolus batinahensis , sp. nov.

Figs. 1–29 , 88–90 , 100–101 , 106–123 , 136 , 146–148 , Tab. 1

Vachoniolus globimanus : Fet et al., 2003: 3, tab. 1; Soleglad & Fet, 2003a: 5; Soleglad & Fet, 2003b: 7, 149, 151–152, fig. B-1, B-2; Santiago-Blay, Soleglad & Fet, 2004: 8.

Holotype: adult ♂, Oman: Al Batinah plain, 10–15 km W Barka, Al Abyad pipeline road, UV detection, coastal dunes, fine sand, near shrub, 23°41.9'N 57° 40.57'E, 50 m a.s.l., 13 October 1993, 22:30 h, leg. G. Lowe, A.S. Gardner & S.M. Farook, NHMB.

Paratypes: Oman: 23 ♂, 5 ♀, 5 juveniles, Al Batinah plain, 10–15 km W Barka, Al Abyad pipeline road, UV detection, coastal sand dunes, sand flats, scattered vegetation, Acacia woodland, coarser sand mostly near or at bases of vegetation, 23°40.62'N 57° 45.77'E, 50 m a.s.l., 13 October 1993, 19:03 h, leg. G. Lowe, A.S. Gardner & S.M. Farook, NHMB, EV (1 ♂) , FKCP (2 ♂, 1 ♀) , GL (2 ♂, 1 ♀) , MNHN (2 ♂, 1 ♀) , VF (1 ♂); 7 ♂, 2 juveniles, Al Batinah plain, 10–15 km W Barka, Al Abyad pipeline road, UV detection, coastal sand dunes and flats, edge of Acacia woodland, sparse vegetation, 23°41.16'N 57°43.61'E, 50 m a.s.l., 13 October 1993, 21:05 h, leg. G. Lowe, A.S. Gardner & S.M. Farook, NHMB ; 16 ♂, 7 ♀, 9 juveniles, same locality as holotype, NHMB, ONHM (5 ♂, 2 ♀, 1 juvenile) , FKCP (1 ♀) ; 1 ♀, near Za'faran, W side of Khawr Sallan , NW of Sohar, on earth in date garden, 24°24'N 56°42'E, 9 m a.s.l., 7 April 1994, 23:00 h, leg. K. Roberts, C.J.N. Roberts & M.D. Gallagher MDG 8597, NHMB ; 2 ♂, S margins of Al Abyad dune field, 23°34'N 57°43'E, 50 m a.s.l., 14 May 1994, leg. A.S. Gardner, BMNH ; 1 ♂, 2 ♀, near Khatmat Milahah , in and near chenopod scrub and Prosopis tree on dusty soil near sabkha, 24°57.36'N 56°22.33'E, 9 June 1994, 19:00–21:00 h, leg. M.D. Gallagher MDG 8601, NHMB ; 3 ♂, Al Hayl , Muscat, on sand, area with Prosopis trees, 23°37.5'N 58°15.5'E, 28 September 1994, leg. A.S. Gardner, NHMB ; 3 ♂, Shinass , on fine gravel on raised beach with scattered grasses near mangrove creek, in moonlight, 24°42.9'N 56°28.62'E, 3 m a.s.l., 12 October 1995, 22:00 h, leg. M.W. Balkenohl & M.D. Gallagher MDG 8739, NHMB ; 3 ♂, border post, near Khatmat Milahah , 24°55.5'N 56°21.1'E, 16 October 1999, leg. I.D. Harrison, ONHM 21,22,23/99; 1 juvenile, Al Batinah plain, W Barka, Al Abyad pipeline road (site F/1), UV detection, sand dunes and flats, in shrub, 23°41.95'N 52°44.81'E, 50 m a.s.l., 18 January 2000, 19:30–22:00 h, leg. A. Winkler, NHMB .

Diagnosis. Medium to large sized Vachoniolus , adults 45–65 mm; base color yellow to orange-yellow with or without weak fuscous patterns on carapace and tergites ( Figs. 1–6 , 136 ); metasoma and telson without melanic pigmentation; tergites smooth except for granules along posterior margins; positions of obsolete lateral carinae of tergites III–VI marked posteriorly by 2–3 granules; metasomal segments relatively stout ( Figs. 14–15 ), L/W ratios: I 1.14–1.40, II 1.37–1.71, III 1.49–1.94, IV 1.85– 2.38, V 2.08–2.79; metasoma I–II with dorsolateral surfaces smooth to sparsely shagreened; dorsosubmedian carinae on metasoma II–III weak, with widely spaced granules separated by two or more granule lengths; ventrosubmedian carinae of metasoma II–III crenulate to serrate with small to moderate sized, closely spaced dentate granules separated by one granule length or less, 5–9 granules on posterior half of carina; telson with moderately long aculeus, vesicle L/ telson L 0.47–0.57; pedipalp femur with trichobothrium d 5 either proximal or distal to e 2, distance ratio (d 5 – e 2)/(e 2 – e 1) median value 0.11 ( Figs. 20 , 111 ); pedipalp patella orthobothriotaxic with 7 trichobothria on external surface ( Figs. 21–22 ); pedipalp chela manus smooth; tibial spurs always present on legs III–IV.

Etymology. The name derives from the Al Batinah coastal plain to which this species is endemic.

Comparisons. Other species of Vachoniolus are differentiated from V. batinahensis by: neobothriotaxy (8–9 trichobothria) on the external surface of the pedipalp patella; femoral trichobothrium d 5 nearly always distal to, and usually well separated from e 2; often partial reduction or loss of tibial spurs on legs III–IV. In addition: V. gallagheri sp. nov., and V. iranus Navidpour et al., 2008 , further differ in having the male pedipalp chela manus finely granulated or shagreened; V. gallagheri differs in having shorter metasomal segments (relative to carapace length), stronger dentition on ventrosubmedian carinae of metasoma II–III, and more stout pedipalp segments; V. iranus differs in its smaller size, more slender metasoma and telson, and melanic pigmentation pattern on carapace and pedipalps ( Fig. 84 ) (Navidpour et al., 2008); V. globimanus differs in having a more slender metasoma and telson, and greater numbers of posterior denticles on ventrosubmedian carinae of metasoma II–III.

Description (holotype male unless otherwise specified).

Coloration ( Figs. 1–2 ). Base color light orange-yellow with pattern of faint underlying fuscosity on carapace and tergites; superciliary carinae dark; telson with aculeus castaneous.

Carapace ( Fig. 9 ). Subrectangular, trapezoidal, anterior interocular width 0.48 times posterior width; surface convex with lateral flanks moderately sloped; anterior margin weakly convex, posterior margin nearly straight; coarse to fine granulation of variable density present on most of carapace; coarse granules on anterior interocular area between lateral eyes, inner margins of lateral eyes, anterior margin of carapace, and superciliary carinae; positions of central median carinae marked by longitudinal series of coarse granules; area between superciliary carinae, lateral and posterior areas around median ocular tubercle smooth; lateral flanks of carapace with medium to fine granulation; other carinae obsolete; posterior median sulcus and adjacent lateral surfaces smooth; median area of posterior margin of carapace bordered by transverse band of dense, fine granulation; median eyes large, ocular tubercle prominent, wide, interocular distance exceeding two ocular diameters; 4 lateral eyes on each side, anterior 3 ocelli equal in size, 4 th ocellus reduced; 8 macrosetae on anterior margin, carapace otherwise devoid of macrosetae.

Chelicera (paratype male) ( Figs. 10–11 ). Dorsal surface of manus smooth, convex, with medial subapical transverse series of small granules; dorsointernal carina at base of fixed finger with larger dentate granules; chaetotaxy: two short pale macrosetae on apical margin of manus, one on medial subapical area, amidst coarse granules; long reddish macroseta on dorsointernal carina; movable finger smooth, without macrosetae, ventral surface of manus smooth, with numerous long, fine microsetae on middle and internal surfaces, more dense on interior aspect, extending dorsally to base of fixed finger; ventral surfaces of fixed and movable fingers with dense brush of microsetae; dentition: fingers with normal buthid dentition (Vachon, 1963; Sissom, 1990); fixed finger with large distal tine, smaller subdistal denticle and large proximal bicusp; two large denticles on ventral surface, proximal denticle smaller than distal; movable finger with large dorsal and ventral distal tines; dorsal margin of movable finger with two large triangulate denticles and pair of small proximal denticles; ventral margin armed with two robust denticles of equal size.

Coxosternal area ( Figs. 2, 4 ). Coxae smooth, lustrous, without distinct carinae; coarse granules along anterior margin of coxa II, proximal anterior margin of coxa III; anterior margin with 2–3 macrosetae on coxa II, 4 macrosetae on coxa III; coxa IV finely shagreened on posterior proximal margin and anterior surface, with single basal macroseta; sternum elongate, subpentagonal, angled downward anteriorly, with deep postero-median ovoid excavation; genital opercula smooth, with 3–4 macrosetae; genital papillae present.

Pectines ( Figs. 2, 4 , 27 ). Basal piece smooth, with deep anterior median sulcus, and 6 macrosetae; pectines long, tips extending to middle of trochanter IV; pectines with 3 marginal lamellae, small accessory lamella distal to first marginal lamella, 6–7 middle lamellae, 22–22 teeth; pectine teeth elongate, proximal teeth slightly shorter than middle and distal teeth; marginal lamellae, middle lamellae and fulcra with dense short, reddish macrosetae; fulcra with 7–13 setae; basal teeth not overlapping when anterior margins of pectines align with posterior margins of coxae IV.

Mesosoma ( Figs. 1–4 ). Tergites: pretergites smooth, lustrous; median carina nearly obsolete on tergite I, weak and granulose on II–VI; tergites I–VI with lateral carinae obsolete, marked at posterior margin by single granules on I, double granules on II–VI; tergite VII with weak median hump, and two pairs of weak granulated lateral carinae; posterior margins of all tergites nearly straight, smooth; tergites I–VI densely, finely shagreened, with coarse granules along posterior margins; tergite V finely shagreened medially, finely granulated laterally; all tergites devoid of macrosetae, lateral margins microdenticulate. Sternites: sternites III–VI smooth, lustrous, lacking carinae; sternite III with anterior lateral areas finely shagreened; sternite VII with smooth, nearly obsolete paired median carinae and weak, smooth paired lateral carinae, medial surfaces smooth, lateral surfaces lightly shagreened; sternites III– VI with smooth posterior margins, finely denticulate lateral margins, dentate-granulate posterolateral corners; sternite VII with smooth posterior margin, dentate lateral margins. Chaetotaxy: sternite III with 13 short macrosetae in medial area, IV–VI with paired medial macrosetae, VII with one pair of macrosetae on median carinae, one pair on anterior lateral surface; posterior margins of sternites with short to medium length setae on left and right sides: III–IV 7–7 (left–right), V 8–8, VI 6–3; lateral margins of sternites with well spaced macrosetae: III 2–2 (left–right), IV 9–6, V 7–6, VI 6–6, VII 1–2.

Hemispermatophore (paratype male) ( Figs. 12–13 ). Flagelliform; trunk elongate, slender; flagellum long, filiform, pars recta 0.75 times length of trunk, pars reflecta about equal to length of trunk; inner lobe a broad lamina, gently tapering with blunt apex; median and outer lobes shorter, laminate, partially fused, tapering to fine apical processes, basal lobe a short, blunt knob; measurements: trunk length (to base of flagellum) 3.4 mm, pars recta 2.5 mm, pars reflecta 3.3 mm, inner lobe (from base of flagellum) 670 µm, median lobe (from juncture with inner lobe) 280 µm, outer lobe (from juncture with median lobe) 265 µm, basal lobe 30 µm.

Metasoma ( Figs. 14–15 ). Long, with robust segments, total length plus telson length 6.4 times carapace length. Carination: metasoma I with 10 complete carinae; metasoma II–III with 8 complete carinae, median lateral carinae confined to posterior 1/2 of each segment; metasoma IV with 4 carinae; metasoma V with 3 carinae; dorsosubmedian carinae weak with small, noncontiguous granules on I–III, obsolete on IV; dorsolateral carinae moderate on I–III with large dentate granules, weak on IV with smaller granules, obsolete on V; median lateral carinae moderate, granulate on I, weak, granulate on II, obsolete and marked by row of granules on III; ventrolateral carinae on I–II moderate, smooth, weakly granulate posteriorly, on III strong, granulate with larger granules posteriorly, on IV weak, granulate, on V strong with mixed medium to large dentate granules; ventrosubmedian carinae weak, smooth on I, moderate, smooth to granulate on II, strong, regularly dentate-granulate on III, obsolete on IV; posterior half of ventrosubmedian carina with 6–7 dentate granules on II, 5–6 on III; ventrosubmedian carinae on V obsolete, marked by series of enlarged dentate granules on anterior 1/2 of segment; ventromedian carina on V moderate, studded with large dentate granules; 6 denticles on ventral anal arc, left lateral anal lobe with 3 denticles, right lobe with 4. Granulation: dorsal surfaces smooth on all segments, concave on I– IV, convex on V; dorsolateral surfaces smooth to sparsely shagreened on all segments, lateral surfaces smooth to lightly shagreened on I–III, shagreened IV–V; ventrolateral and ventral surfaces smooth on I–II, lightly shagreened on III, densely shagreened on IV–V. Chaetotaxy: carinal macrosetae (left–right) dorsosubmedian: I, 0–0, II 1–2, III 3–2, IV 2–3, dorsolateral: I, 0–0, II 2–1, III 1–2, IV 2–3; ventrolateral: I 2–2, II 2– 2, III 2–2, IV 3–3; ventrosubmedian: I 1–1, II 2–2, III 2– 2, IV 2–2, V 3–3; intercarinal macrosetae: metasoma V 11–13 lateral setae, 1 postero-lateral pair on ventral surface.

Telson ( Figs. 14–15 ). Vesicle slim, width 0.68 times metasoma V width, dorsal and lateral surfaces smooth, lustrous, ventral surface studded with granules, bearing numerous long reddish macrosetae: 2–2 on lateral surfaces, 20 on ventral surface; aculeus slender, nearly as long as vesicle.

Pedipalp ( Figs. 18–22 , 88–90 , 100 ). Femur ( Figs. 20 , 88 ): short, stout, 0.83 times carapace length, 2.6 times longer than wide; dorsoexternal, dorsointernal and ventrointernal carinae strong, with robust dentate granules; external surface mostly smooth with scattered small and large granules; dorsal surface flat, mostly smooth, lustrous, with scattered small and large granules, ventral surface smooth, lustrous, proximally concave, distally convex, with sparse small granules; internal surface divided by weak internal carina bearing irregular small and large conical granules, upper and lower surfaces with dispersed small granules; dorsoexternal carina with 2 distal macrosetae, external surface with 1 basal, 6–7 distal macrosetae. Patella ( Figs. 21–22 , 89 ): short, stout, 0.9 times carapace length, 2 times longer than wide; dorsointernal carina strong, granulose; ventrointernal carina strong, with large dentate granules; internal carina weak, marked by coarse dentate granules; other carinae obsolete; intercarinal surfaces smooth, lustrous, internal surface with sparse fine granules. Chela ( Figs. 18–19 , 90 , 100–101 ): relatively short, 1.4 times carapace length; manus extremely swollen, subglobose, width 0.58 times carapace length, fingers short, movable finger 0.93 times ventral manus length; surfaces smooth, lustrous, all carinae obsolete; dentate margins of finger straight, without proximal scalloping; closure of fingers leaves narrow linear proximal gap, with tips of fingers apically divergent; manus mostly bare, with sparse short macrosetae; movable finger with numerous short macrosetae on ventral aspect, most dense sub-apically; 8 primary denticle subrows on fixed and movable fingers; fixed fingers with 8 internal accessory denticles, 6–7 external accessory denticles; movable fingers with 8 internal and external accessory denticles, tip of movable finger with 3 subdistal denticles ( Fig. 100 ). Trichobothrial pattern: Orthobothriotaxic, type Aβ (Vachon, 1974, 1975); trichobothrium d 5 located slightly distal to e 2; femur d 2, patella d 2, chela Eb 3, Esb and esb petite; db on fixed finger level with esb; dt approximately midway between est and et.

Legs ( Figs. 1–8 , 16–17 ). Legs I–II robust, legs III–IV moderately slender; ventral carinae on femur I with large separated denticles, on femur II–III contiguously dentate, on femur IV finely denticulate; legs III–IV with tibial spurs; retrolateral pedal spurs on legs I–IV simple, without setae; prolateral pedal spurs basally bifurcate with (left–right) 4–3, 5–5, 11–14, 12–10 setae; tibiae I– III with retrosuperior bristle-combs ( Fig. 16 ) with (left– right) 9–9, 11–13, 17–19 setae; basitarsi I–III bristle-combs present ( Fig. 16 ) with seta counts: retrosuperior 12–11, 17–16, 26–28, retroinferior 8–9, 11–10, 16–16, ventral surfaces of telotarsi with short macrosetae on leg I, medium length macrosetae on legs II–III ( Fig. 17 ), long macrosetae in leg IV.

Measurements of holotype male (mm). Total L 58.50; metasoma and telson L 38.00; carapace L 5.89, anterior W 3.10, posterior W 6.43, carapace preocular L 2.58; metasomal segments (L/W/D) I 4.99/3.83/3.27, II 5.85/3.74/3.35, III 6.19/3.61/3.10, IV 7.22/3.40/3.04, V 7.83/3.18/2.77; telson L 6.19; vesicle L 3.01, W 2.15, D 2.19; pedipalp chela L 8.17, chela manus ventral L 4.64, chela manus W 3.44, D 3.66, fixed finger L 2.92, movable finger L 4.30; pedipalp femur L 4.90, W 1.89, patella L 5.33, W 2.67; pectine L 6.62, leg III patella L 5.33, W 1.67.

Measurements of paratype female (adult from Al Abyad dune field) (mm). total L 59.00; metasoma and telson L 36.50; carapace L 6.28, anterior W 3.53, posterior W 7.80, carapace preocular L 2.89; metasomal segments (L/W/D) I 4.64/3.67/3.34, II 5.59/3.53/3.41, III 5.93/3.35/3.27, IV 6.83/3.10/2.98, V 7.57/3.39/2.77; telson L 6.54; vesicle L 3.18, W 2.41, D 2.28; pedipalp chela L 8.20, chela manus ventral L 3.35, chela manus W 1.91, D 2.15, fixed finger L 3.91, movable finger L 5.09; pedipalp femur L 4.39, W 1.81, patella L 5.33, W 2.25; pectine L 4.18, leg III patella L 5.09, W 1.88.

Variation. Biometrics were taken from 33 adults (26 males, 7 females). Adults had body length 39–62 mm (mean ± SD 51.6 ± 5.4 mm) and carapace length 4.4–6.3 mm (5.34 ± 0.40 mm). Pedipalp finger primary denticle subrows for adults ( Figs. 100–101 ): of 66 fixed fingers, there was 1 finger with 5 subrows, 7 with 6, 29 with 7, and 29 with 8; of 66 movable fingers, there was 1 finger each with 1, 3 and 4 subrows (teratological cases), 2 fingers with 5 subrows, 3 with 6, 18 with 7, 36 with 8, and 4 with 9. Number of dentate granules on the posterior half of the ventrosubmedian carina of metasoma II–III: on II, 3 carinae with 5 granules, 17 with 6, 25 with 7, 17 with 8, 2 with 9; on III, 15 carinae with 5 granules, 32 with 6, 18 with 7 and 1 with 8. Tibial spurs were present in nearly all cases: of 93 leg III tibiae, spurs were present in 91 (97.8 %), absent in 2; spurs were present in all of 93 leg IV tibiae (100 %). Variation in morphometrics is summarized in Figs. 106– 111 , Tab. 1. A morphometric parameter of special interest is the pedipalp femur trichobothrial distance ratio (d 5 – e 2)/(e 2 – e 1). The character state (d 5 – e 2)> 0 (i.e. d 5 distal to e 2) was previously used as a diagnostic criterion for the genus Vachoniolus . In V. batinahensis , a significant number of femora (21/122 = 17.2 %) had (d 5 – e 2) ≤ 0 (i.e. d 5 level with or proximal to e 2) ( Fig. 111 ), and hence this character cannot be used for generic diagnosis.

Sexual dimorphism: females differed from males as follows: granulation finer, sparser on carapace; tergites smooth; pedipalp femur smooth, internal surface without large dentate granules; pedipalp patella with dorsointernal and ventrointernal carinae weaker with smaller granules, internal surface without large dentate granules ( Fig. 25 ); pedipalp chela manus not strongly swollen ( Figs. 23–24 ); metasoma I–IV with stronger granulation and dentition on ventrolateral and ventrosubmedian carinae; ventrolateral carinae strong, granulate on metasoma I, strong, dentate-granulate on II, strong, dentate with enlarged posterior denticles on III, moderate, granulate on IV; ventrosubmedian carinae weak to moderate, finely granulate on I, strong, dentate with enlarged posterior denticles on II–III, weak, almost obsolete with irregular fine granules on IV; lateral surfaces of metasoma IV–V smooth; pectines much shorter ( Fig. 26 ), tips falling well short of distal ends of coxae IV ( Figs. 6, 8 ). Pectine teeth (including immatures): males 15–24 (of 129 combs from n = 66 males: 2 combs with 15 teeth, 5 with 18, 19 with 19, 32 with 20, 41 with 21, 23 with 22, 6 with 23, and 1 with 24), females 10–15 (of 40 combs from n = 20 females: 1 comb with 10 teeth, 1 with 11, 3 with 12, 8 with 13, 19 with 14, 8 with 15). There was significant sexual dimorphism in morphometrics ( Table 1): females tended to have shorter pedipalp femur, patella, chela and metasoma I–V relative to carapace length, more slender pedipalp patella, and pedipalp chela movable finger longer relative to manus.

Juveniles: differed from adults in having weaker, less granulose carination on the pedipalp femur and patella, and fewer macrosetae on the tibiae, basitarsi and telotarsi of all legs. The manus of the pedipalp chela in sub-adult males was less swollen than in adults, and in juveniles it was not more swollen than in females of similar size. The pronounced expansion of the manus in males occurred abruptly, when the carapace attained a length of ca. 4.0– 4.5 mm ( Fig. 28 ). In the smallest juveniles (carapace L 1.58–1.75 mm, mean ± SD 1.68 ± 0.06 mm, n = 7) the tibia, basitarsus and telotarsus of legs I–III lacked macrosetae and bristle combs, bearing instead a series of elongate spiniform processes extending from their retrosuperior margins ( Figs. 112– 114 ). These processes (‘spine combs’) were fully sheathed with fluorescent epicuticle ( Figs. 115–117 ). The range (mean ± SD) for spine counts was: tibia I 0–1 (0.46 ± 0.52, n = 13), basitarsus I 4–6 (5.15 ± 0.69, n = 13), telotarsus I 2–3 (2.85 ± 0.38, n = 13); tibia II 1–2 (1.21 ± 0.43, n = 14), basitarsus II 4–8 (5.93 ± 1.21, n = 14), telotarsus II 3–4 (3.21 ± 0.43, n = 14); tibia III 1–3 (1.71 ± 0.73, n = 14), basitarsus III 4–8 (6.14 ± 0.95, n = 14), telotarsus III 3–6 (4.50 ± 0.85, n = 14). In juveniles with spine combs on legs I–III, the tibial and tarsal segments of leg IV lacked such armature (although a few small marginal denticles were present), and also lacked macrosetae.

Distribution ( Figs. 146–148 ). V. batinahensis is endemic to sandy areas of the Al Batinah coastal plain of northern Oman, at elevations <50 m a.s.l.. The northernmost coastal record is at the border post of Khatmat Milahah, and it could also occur in the adjacent coastal United Arab Emirates if there were suitable dune habitats. Considering its restricted distribution, there is a concern that this species might be vulnerable to loss of habitat caused by land development along the heavily populated Batinah coast. Conservation of coastal dune habitats is recommended to protect this unique relict scorpion, which is an important part of the endemic biodiversity and evolutionary heritage of Oman.

Ecology. This is psammophilous species, inhabiting aeolian dunes. It was the most numerous scorpion in Acacia woodlands at Al Abyad, west of Barka. Most individuals were found at night by ultraviolet detection resting at the bases of vegetation, where they excavated burrows. One individual at this site was observed being devoured by a large sparassid spider in a shrub. Other collections were made on fine sandy soils, in association with Prosopis trees. Two other buthid scorpions, Androctonus crassicauda (Olivier, 1807) and Orthochirus innesi Simon, 1910 , were collected on sandy substrates at the type locality.

Figures

Figures 1–8: Vachoniolus batinahensis, sp. nov., holotype male (1–4) and paratype female from 11 km W Barka (5–8). Habitus viewed under reflected white light (1–2, 5–6) or UV fluorescence (3–4, 7–8). 1, 3, 5, 7. Dorsal aspect. 2, 4, 6, 8. Ventral aspect. Scale bar: 10 mm.

Figures 9–17: Vachoniolus batinahensis, sp. nov. 9, 14–17, holotype male; 10–13, paratype male (same locality as holotype). 9. Carapace, dorsal aspect. 10. Right chelicera, dorsal aspect. 11. Right chelicera, ventral aspect. 12–13. Right hemispermatophore, lobes at base of flagellum. 12, convex aspect; 13 outer aspect. 14–15. Metasoma and telson. 14. Right lateral aspect. 15. Ventral aspect. 16. Right basitarsus and telotarsus III, retrolateral aspect. 17. Right telotarsus III, ventral aspect. Scale bar: 9, 16: 3 mm; 10, 11: 1.7 mm; 12, 13: 1 mm; 14, 15: 5.7 mm; 17: 1.5 mm.

Figures 18–27: Vachoniolus batinahensis, sp. nov. 18–22, 27, holotype male; 23–26, paratype female (Al Abyad dune field, W of Barka). 18. Right pedipalp chela of male, external aspect. 19. Right pedipalp chela of male, ventral aspect. 20. Right pedipalp femur of male, dorsal aspect. 21. Right pedipalp patella of male, dorsal aspect. 22. Right pedipalp patella of male, external aspect. 23. Right pedipalp chela of female, external aspect. 24. Right pedipalp chela of female, ventral aspect. 25. Right pedipalp patella of female, dorsal aspect. 26. Left pectine, female, ventral aspect. 27. Left pectine, male, ventral aspect. Scale bar: 18, 23–27: 3 mm; 20–22: 2 mm. Trichobothrial notation after Vachon (1974).

Figures 28–29: Sexual dimorphism in ontogenetic scaling of the pedipalp chela of Vachoniolus batinahensis, sp. nov. 28. Double logarithmic plot of pedipalp chela width versus carapace length. 29. Double logarithmic plot of pedipalp chela length versus carapace length. Filled circles: males; open circles: females. Black lines: least squares linear regression fits to segregated subsets of male data points, showing discontinuous development of the chela during growth. Gray lines: fits to entire set of female data points, showing continuous development of the chela. Axis label units in mm.

Figures 88–99: Pedipalp segments of Vachoniolus, species, viewed under UV fluorescence. 88–90, V. batinahensis, sp. nov., holotype male; 91–93, V. gallagheri, sp. nov., holotype male; 94–96, V. globimanus, male from Barik; 97–99, V. iranus, male from Iran. 88, 91, 94, 97: pedipalp femur, dorsal aspect; 89, 92, 95, 98: pedipalp patella, dorsal aspect; 90, 93, 96, 99: pedipalp chela, external aspect. Scale bar: 88–89, 99: 2.0 mm; 90: 2.4 mm; 91–92: 1.7 mm; 93, 96: 2.7 mm; 94–95: 2.1 mm; 97–98: 1.3 mm.

Figures 100–105: Pedipalp finger dentition of Vachoniolus species in Oman. Each figure shows a sketch of the denticle patterns on the dentate margins of right fixed finger (left drawing), and right movable finger (right drawing). Position of internal fixed finger trichobothrium it is indicated. 100. V. batinahensis, sp. nov., holotype male. 101. V. batinahensis, sp. nov., paratype female (al Abyad). 102. V. gallagheri, sp. nov., holotype male. 103. V. gallagheri, sp. nov., paratype female (N of Adam). 104. V. globimanus, female (Marsawdad). 105. V. globimanus, male (Shigag).

Figures 106–111: Graphical illustration of variation in selected morphometric ratios of Vachoniolus. 106. Scatter plot of male variation in slenderness of metasoma I and relative length of pectine (metasoma I L/W vs. pectine L/ carapace L). 107. Scatter plot of variation in relative length of metasoma IV and slenderness of telson (metasoma IV L/ carapace L vs. telson L/W). 108. Scatter plot of male variation in slenderness of metasoma IV and relative proportion of pedipalp chela fixed finger (metasoma IV L/W vs. pedipalp chela fixed finger L/ manus L). 109. Scatter plot of male variation in slenderness of metasoma V and pedipalp femur (metasoma v L/W vs. pedipalp femur L/W). 110. Scatter plot of male variation in slenderness of pedipalp femur and patella (pedipalp femur L/W vs. pedipalp patella L/W). 111. Histogram plots showing distributions of the trichobothrial distance ratio (d5–e2)/(e2–e1) (data from both sexes). Vertical line is crossover point for d5 relative to e2. Note: each histogram bar represents the number of cases with ratio ≤ right abscissa tick mark; for V. globimanus, all data ≤ 0 are actually equal to 0 (i.e. no cases of d5 proximal to e2). The ratio distribution of V. batinahensis was significantly different from that of V. gallagheri (P = 0.0001), and the latter was also significantly different from that of V. globimanus (P = 4·10-6) (Mann-Whitney test). Color codes of all plots: green: V. batinahensis; yellow: V. gallagheri; magenta: V. globimanus; blue: V. iranus. Data in 106–110 from adults, in 111 from all ages.

Figures 112–123: Tarsal spine combs and bristle combs on tibia, telotarsus and basitarsus of juvenile Vachoniolus batinahensis, sp. nov. 112–117: left legs, juvenile female, Al Abyad, carapace length 1.68 mm. 118–123: right legs, juvenile female, Al Abyad, carapace length 2.8 mm. 112–114, 118–120: visible light trans-illumination; 115–117, 121–123: UV epifluorescence. 112, 115, 118, 121: leg I; 113, 116, 119, 122: leg II; 114, 117, 120, 123: leg III. Retrolateral aspect shown in all figures. Scale bars: 5 mm (across rows).

Figures 136–141: In vivo habitus and behavior of Vachoniolus in Oman. 136. V. batinahensis sp. nov., adult male, Al Abyad dune field, W of Barka. 137–141. V. globimanus, Wadi Muqshin, NW of Montesar. 137–138. Adult males. 139. Adult female. 140–141. Pairs of adult males and females engaged in promenade à deux (photos of captured animals taken in the field, in the early morning). The male in 140 is using legs II–III to dig into the sand surface (note motion blur of sand being thrown behind his mesosoma). The pair in 141 is performing their dance in a plastic (polypropylene) tray.

Figures 146–148: Maps showing collection sites of Vachoniolus material examined in this study. 146. Records plotted on geopolitical map. Arrows: type localities for V. batinahensis and V. gallagheri, and approximate type locality of V. minipectenibus (= V. globimanus). 147. Records plotted on color topographic map with shaded relief. 148. Records plotted on terrain map obtained by satellite imagery. Green circles: V. batinahensis, sp. nov.; yellow circles: V. gallagheri, sp. nov.; magenta circles: V. globimanus.

Figures 84–87: Vachoniolus iranus Navidpour et al., 2008, paratype male. Habitus viewed under reflected white light (84, 86) or UV fluorescence (85, 87). 84–85. Dorsal aspect. 86–87. Ventral aspect. Scale bar: 5 mm.