Hottentotta saxinatans, Lowe, 2010

Lowe, Graeme, 2010, Two new species of Hottentotta Birula, 1908 (Scorpiones: Buthidae) from northern Oman, Euscorpius 103 (103), pp. 1-23 : 8-17

Hottentotta saxinatans , sp. nov.

Figs. 27–52 , 55–56 , 60 , 65–66 , Tab. 1

Holotype: adult ♂, Oman, Jabal Shams , Jabal Akhdar, UV detection, rocky wadi, vegetated boulder strewn slopes, resting on boulders or tree trunks, 23°14.31' N 57°11.64' E, 1900 m a.s.l., 14 October 1993, 21:12 h, leg. G. Lowe & M.D. Gallagher, NHMB.

Paratypes: Oman: 1 ♀, 11 October 1993, leg. A.S. Gardner, FKCP ; 3 ♂, 5 ♀, 3 juveniles, same locality as holotype, GL, NHMB, BMNH ; 1 ♀, 1 juvenile, Jabal Shams, Jabal Akhdar, UV detection on slope around wadi, narrow rock-bottomed wadi, with boulders, 23°14.27' N 57°11.68' E, 1870 m a.s.l., 2 October 1994, 19:00–20:00 h, leg. G. Lowe & M.D. Gallagher, ONHM ; 5 ♀, 3 juveniles, Jabal Shams, UV detection on boulders on slopes above gravelly wadi, with trees, boulder slopes on sides, 23°14.29' N 57°11.62' E, 1855 m a.s.l., 2 October 1994, leg. G. Lowe & M.D. Gallagher, GL, NHMB, MNHN ; 1 ♂, 3 ♀, 3 juveniles, Qayut , Jabal Akhdar, 23°09.74' N 57°27.84' E, 2150 m a.s.l., 11 May 1995, leg. A.S. Gardner, ONHM ; 1 ♂, Jabal Shams , in crevice in tree at 1.5 m above ground, 23°13.65' N 57°12.22' E, 1850 m a.s.l., 19 October 1995, 22:00 h, leg. M.D. Gallagher, ONHM .

Diagnosis. Medium sized Hottentotta (Sissom, 1990; Kovařík, 2007; Sun, Zhu & Lourenço, 2010), adults 54– 69 mm; color uniform bright yellow, with faint fuscosity on ventrolateral and ventrosubmedian carinae of metasoma II–IV, and ventrolateral, ventrosubmedian and ventromedian carinae of metasoma V; carapace and tergites with moderate, finely granular carinae; anterior margin of carapace with fine granules; posterior margins of tergites with carinae protruding in short spiniform processes; carapace, tergite, mesosoma and pedipalps finely granulated or shagreened; carapace, tergites, sternites, pedipalps, legs, metasoma and telson sparsely setose, nearly bare, macrosetae short, fine; genital opercula moderately to sparsely setose; posterior margin of tergites I– VI with few short macrosetae or bare; pedipalps slender, femur L/ W 3.4 –3.8, patella L/ W 3.0 – 3.4, chela L/ W 6.1 –7.3; pedipalp chela without carinae; pedipalp fixed finger primary denticles divided into 13– 14 subrows (92 % of cases), movable finger primary denticles divided into 13–14 subrows (97 % of cases); male pedipalp fingers without basal scalloping; metasoma moderately elongate, segment L/W ratios: metasoma I 1.0–1.25, metasoma II 1.3–1.5 metasoma III 1.5 – 1.7 , metasoma IV 1.8–2.1, metasoma V 2.1 – 2.4 ; metasoma I– III with 10 carinae, median lateral carinae strong, complete on I–II, weak and incomplete on III; lateral surfaces of metasoma I–IV finely granulated or shagreened; pectine teeth in males 27–29, in females 23– 27 .

Comparisons. The sparse setation differentiates this species from those Hottentotta whose pedipalps bear a dense cover of long macrosetae or dense fine pubescence. Among those without dense pilosity on pedipalps, the following are separated by having more stout metasomal segments: H. arenaceus (Purcell, 1902) , H. conspersus (Thorell, 1876) , H. finneganae Kovařík, 2007 , H. hottentotta (Fabricius, 1787) , H. jalalabadensis Kovařík, 2007 , H. minax (L. Koch, 1875) , H. niloticus (Birula, 1927) , H. pachyurus (Pocock, 1897) , H. polystictus (Pocock, 1896) , H. rugiscutus (Pocock, 1897) , H. stockwelli Kovařík, 2007 and H. trilineatus (Peters, 1861) ; the Asian species H. alticola (Pocock, 1895) , H. buchariensis (Birula, 1897) and H. penjabensis (Birula, 1897) differ in having more elongate metasomal segments (male L/D ratio: metasoma IV> 2.1, metasoma V> 2.4), greater numbers of subrows of primary denticles on pedipalp fixed and movable fingers (14–16), and varying degrees of fuscous pigmentation on the carapace pedipalps, tergites and metasoma; H. judaicus (Simon, 1872) differs in its uniform black coloration and more stout pedipalps (pedipalp patella L/W <3.0); H. socotrensis (Pocock, 1889) has a more elongate carapace with anterior fuscosity, pedipalps with shorter fingers, and broader manus, and black chelicerae; H. khoozestanus Navidpour et al., 2008 is mostly yellow in color, but is much larger (120 mm), has 16 subrows of primary denticles on the pedipalp fingers, and more slender metasomal segments.

In Oman, H. jayakari (Pocock, 1895) , H. salei (Vachon, 1980) and H. pellucidus sp. nov., are differentiated by: dense pilosity on the pedipalps, stronger carinae and coarser granulation on carapace, tergites and metasoma; H. jayakari and H. salei also differ in their dark pigmentation, and strong scalloping at the base of the male pedipalp fingers.

Etymology. The specific epithet refers to the rapid, fluid movement of this species in rocky habitats, giving the impression of effortlessly floating or swimming over a sea of rocks and boulders.

Description (holotype male unless otherwise specified).

Coloration ( Figs. 27–28 ). Entire body uniform pale yellow (bright ochraceous yellow in life); without contrasting markings; melanic pigmentation confined to median and lateral eyes; denticles of chelicerae and pedipalp fingers, articular condyles of pedipalp movable fingers, tarsal ungues and aculeus of telson castaneous.

Carapace ( Figs. 27 , 31 ). Subquadrate, slightly wider than long, dorsoventrally compressed, lateral flanks shallowly sloped; median eyes slightly raised; lateral eyes with 5 ocelli (3 large, 2 small); anterior margin concave, microgranular, bordered by coarser granules; carination: anterior median, central median and posterior median carinae moderate, finely granular; other carinae indistinct; central median and posterior median carinae not collinear, incompletely joined; supraocular and postocular parts of superciliary carinae finely granular, 9 short macrosetae on anterior margin of carapace; granulation: coarse granules on anterior interocular triangle behind lateral eyes; lateral flanks with coarse to fine granulation; posterior median intercarinal area smooth with few fine granules; area between anterior median carinae mostly smooth with sparse fine granules; posterior margin of carapace with strip of fine granules between posterior median carinae.

Chelicera ( Figs. 32–33 ). Dorsal surface of manus smooth, glabrous, with transverse row of coarse and fine, subdistal granules; dorsointernal carina at base of fixed finger with coarse granules; chaetotaxy: manus with pair of short pale microsetae on apical border; long reddish macroseta on dorsointernal carina; dorsal surface of movable finger with 4 short pale microsetae in distal 2/3; manus ventrally smooth, bearing numerous long, fine microsetae, sparser medially, denser on medio-internal aspect, merging into dense setal brush on ventral aspect of fixed finger; dense fine setae extend to medial surface, more sparse on dorsomedial area at base of fixed finger; ventral surface of movable finger densely setose; dentition: fingers with normal buthid dentition (Vachon, 1963; Sissom, 1990); fixed finger with large distal tine, subdistal denticle and large proximal bicusp, two prominent denticles on ventral surface; movable finger with large dorsal and ventral distal tines; dorsal margin of movable finger with two large triangulate denticles and small proximal bicusp, ventral margin with two large robust denticles.

Coxosternal area ( Fig. 28 ). Coxae minutely shagreened or smooth; fine granulation on anterior margins of coxae II–III, proximal anterior margins of coxa IV, posterior margin of coxae III, proximal posterior margin of coxa IV, posterodistal margins of coxae I–III, and surface of coxa I endite; coxa and endite I with 5–9 macrosetae, endite II with 3 macrosetae; coxa II with 3 anterior marginal macrosetae; coxa III with 4 anterior marginal macrosetae; coxa IV with single basal macroseta; sternum subtriangular, smooth, with deep posteromedian excavation flanked by a pair of macrosetae; genital opercula smooth, each with 4 short macrosetae; genital papillae present.

Pectines ( Figs. 28 , 45 ). Basal piece smooth with deep anteromedian incision, bearing one short macroseta; distal tips of pectines extending to middle of trochanter IV; pectines with 3 marginal lamellae, 9 middle lamellae, plus small intermediate lamella at distal end of basal marginal lamella, 28–28 teeth; marginal lamellae, middle lamellae and fulcra with moderate cover of short reddish macrosetae, 2–5 on fulcra; when anterior margins of both pectines are aligned with posterior margins edges of coxae IV, basal 3 teeth overlap with gap between basal middle lamellae.

Mesosoma ( Figs. 27–28 , 31 ). Tergites: pretergites smooth; tergites I–VI with 3 granulose, moderately strong carinae; median carinae of III–VI and lateral carinae of I–VI with terminal granule projecting slightly beyond posterior margins of tergites; lateral carinae short on tergite I, longer and curved on II–VI; tergite VII with two pairs of granular lateral carinae, and granulated narrow median hump; lateral flanks of all tergites shallowly sloped, with numerous granules; tergites III–V with transverse anterolateral series of granules contiguous with lateral carinae; median intercarinal surfaces with scattered fine and coarse granules; tergites nearly bare with at most one pair of short marginal macrosetae on medial sides of lateral carinae; tergite VII devoid of macrosetae. Sternites: all sternites smooth, lustrous; sternite III without carinae, lateral carinae smooth, weak on sternites IV–V, smooth, moderate on VI; sternite VII with 4 granular carinae, medial pair moderate, lateral pair strong; macroseta counts on medial and lateral surfaces + posterior margin: III 26+12, IV 6+10, V 7+11, VI 6+6, VII 6+2; lateral margins of sternites denticulate, more strongly so on VI–VII, posterior margins microdenticulate on III–VI, granular on VIII.

Hemispermatophore ( Figs. 43–44 ). Flagelliform, trunk elongate, slender; flagellum filiform, long, pars recta 0.34 times length of trunk, pars reflecta 0.6 times length of trunk; inner lobe a broad slightly tapered lamina with truncate apex; median lobe wide, triangulate, outer lobe tapered, apically bent; basal lobe short, uniformly narrow, apically truncate. Measurements (paratype): trunk L (to base of flagellum) 6.1 mm, pars recta 2.1 mm, pars reflecta 3.7 mm, inner lobe (from base of flagellum) 715 µm, median lobe 400 µm, outer lobe 360 µm, basal lobe 160 µm.

Metasoma ( Figs. 27–28 , 36–37 ). Moderately elongate, total length plus telson length 5.4 times carapace length; segments I–III with 10 carinae, segment IV with 8 carinae; segment V with 5 complete carinae; dorsosubmedian carinae strong, moderately to finely granular on I–VI; dorsolateral carinae strong on I–IV, weak on V, granular on all segments, with granulation weaker on VI–V; median lateral carinae granular, strong, complete on metasoma I–II, weak, indistinct on anterior 1/3 of segment III; ventrolateral and ventrosubmedian carinae strong, weakly granulate, almost smooth on I–II, moderately granulate on IV–V; ventromedian carina moderate, finely granulate on V; ventrosubmedian carinae on V weak, finely granulate, confined to anterior 1/3 of segment; dorsal intercarinal surfaces smooth to minutely shagreened on segments I–IV, smooth medially and finely granular laterally on V; dorsolateral intercarinal surfaces moderately granulate on I, finely granulate on II, shagreened in III–IV; lateral, ventrolatera l and ventral intercarinal surfaces of all segments finely granulated or shagreened; ventral surface of metasoma V with additional scattered medium sized granules on posterior half of segment; lateral anal lobes smooth, rounded, not dissected; ventral anal arc with 26 fine ventral granules and 7 coarse ventrolateral granules; chaetotaxy: carinae with small numbers of short macrosetae, intercarinal macrosetae absent; dorsal and lateral surfaces of metasoma I–IV lacking macrosetae, ventrolateral carinae with 1–2 macrosetae, ventrosubmedian carinae with 3 macrosetae including posterior marginal; segment V with 4 lateral macrosetae, and 4 pairs on ventral surface; 4 macrosetae on ventral anal arc.

Telson ( Figs. 36–37 ). Vesicle ovoid, moderately sloped posteriorly; vesicle with dorsal surface smooth, lateral surface smooth with single longitudinal series of fine granules; ventrolateral and ventral surfaces studded with fine granules, bearing 11 short and long macrosetae; aculeus slender, curved, shorter than vesicle.

Pedipalp ( Figs. 38–42 , 47–52 , 55–56 ). Femur ( Fig. 38 ): slender, 3.83 times longer than wide, with 5 moderate, finely granulated carinae; dorsoexternal, dorsointernal and ventrointernal carinae with regular, closely spaced medium to small granules; external and internal carinae with more irregular, widely spaced, larger dentate granules; intercarinal surfaces with scattered fine granules, ventral surface sparsely granulate, nearly smooth; distal external macrosetae sparse, 8–10 setae in ventral row, 3 in dorsal row, carinal setation sparse, intercarinal surfaces lacking macrosetae. Patella ( Figs. 39–40 ): elongate, 3.35 times longer than wide, with 7 granulate carinae; dorsointernal and dorsomedian carinae moderate, finely granulate; dorsoexternal, ventroexternal and ventral carinae weak, finely granulate; external carinae moderate, with weak, fine granulation; ventrointernal carina obsolete; internal carina moderate, with small to medium granules; intercarinal surfaces with sparse fine granules or sparsely shagreened, ventral surfaces nearly smooth; macrosetae sparse. Chela ( Figs. 41–42 , 55–56 ): slender with tenuous fingers, 7.3 times longer than wide; movable finger 2.62 times manus ventral length; external and ventral surfaces of manus smooth, internal and dorsal surfaces with weak, fine granulation; digital carinae weak, other carinae obsolete; fixed and movable fingers smooth, except for internal patch of fine granules at base of fixed finger, dentate margins of fingers without proximal scalloping; manus and fingers with numerous short macrosetae; dense brush of setae on ventral apical area of movable finger; 13 primary denticle subrows on right fixed and movable fingers ( Figs. 55–56 ) and left fixed finger, 11 on left movable finger (anomalous fusion of apical subrows); all denticle subrows flanked by internal and external accessory denticles; movable finger with 4 enlarged subdistal denticles. Trichobothrial pattern ( Figs. 47–52 ): orthobothriotaxic, type Aβ (Vachon, 1974; 1975); femur d 2, patella d 2, chela Eb 3, Esb and esb petite; patella with d 3 internal to dorsomedian carina (Fet, Soleglad & Lowe, 2005); db positioned on fixed finger between est and et (Kovařík, 2007); line joining V 1 and V 2 on manus oblique, not perpendicular to axis of movable finger articulation (Sun, Zhu & Lourenço, 2010).

Legs ( Figs. 27–28 , 34–35 ). Slender; ventral carinae finely denticulate on femora, weakly crenulate on tibiae; legs III–IV with tibial spurs; retrolateral pedal spurs simple, non-setose; prolateral pedal spurs basally bifurcate, bearing single macroseta; prolateral and retrolateral surfaces of basitarsi and telotarsi with numerous short macrosetae, not arranged into bristle-combs; retroventral aspect of basitarsi I–III with row of short, stout macrosetae; ventral aspect of telotarsi I–IV with paired rows of stout spiniform macrosetae; ungues stout, strongly curved.

Measurements of holotype male (mm). Total L 58.00; metasoma and telson L 37.00; carapace L 6.79, anterior W 3.34, posterior W 7.45, preocular L 2.80; metasomal segments (L/D/W) I 5.06/3.47/4.09, II 5.47/3.36/3.60, III 5.85/3.24/3.51, IV 6.73/3.30/3.37, V 7.67/3.21/3.28; telson L 6.95; vesicle L 4.25, D 2.86, W 2.74; pedipalp chela L 14.09, manus ventral L 3.95, chela W 1.93, D 2.08, fixed finger L 9.55, movable finger L 10.33; pedipalp femur L 7.12, W 1.86, patella L 8.05, W 2.40; pectine L 7.92; leg III patella L 6.19, D 1.54, sternite VII L 3.92, W 6.79.

Adult female (same locality as holotype) ( Figs. 29–30 , 46 , 60 ). Differs from male as follows: a larger scorpion, coarser granules on carapace and tergites; pectines shorter, distal tips only extending to end of coxa IV, with 7–8 middle lamellae; pectine teeth smaller, shorter; when anterior margins of both pectines are aligned with posterior margins of coxae IV, basal teeth do not overlap; basal piece with more shallow anteromedian incision; sternite IV with weaker lateral carinae, sternite VII with strong medial carinae.

Measurements of paratype female (mm): total L 68.50; metasoma and telson L 40.00; carapace L 7.42, anterior W 3.84, posterior W 8.55, preocular L 3.09; metasomal segments (L/D/W) I 5.13/3.87/4.62, II 5.88/3.68/4.26, III 6.05/3.72/3.92, IV 7.13/3.61/3.72, V 8.08/3.50/3.70; telson L 7.77; vesicle L 4.56, D 3.26, W 3.29; pedipalp chela L 15.02, manus ventral L 4.16, chela W 2.37, D 2.36, fixed finger L 9.74, movable finger L 10.90; pedipalp femur L7.61, W 2.03, patella L 8.64, W 2.79; pectine L 7.01; leg III patella L6.54, D 1.75; sternite VII L 4.43, W 8.55.

Variation. Juveniles: differed from adults as follows: carapace and tergites with weaker carinae, intercarinal surfaces with weaker granulation or smooth; metasoma I–V with weaker, finely granulated carinae, intercarinal surfaces smooth; telson vesicle more elongate, with more prominent granules on ventral surface; aculeus more stout. Juveniles and sub-adults have contrasting dark pigmentation on ventrosubmedian and ventrolateral carinae of metasoma I–V, and ventromedian carinae of V. In adults, these carinal markings are not as dark, and may be difficult to discern in some individuals.

Sexual dimorphism: males were smaller than females: carapace L 6.19–6.79 (6.49 ± 0.42, n = 2) for adult males, 7.31–7.75 (7.52 ± 0.17, n = 7) for adult females. Morphometric data for adults of both sexes are summarized in Table 1. The limited sample of adult males (n = 2) may account for there being fewer adult morphometric ratios with statistically significant sexual dimorphism. Males had on average significantly longer (relative to carapace) and more slender metasomal segments and pedipalp patellae than females. Pectine teeth: males 27–29 (mode 28): of 22 combs, 4 had 27 teeth, 12 had 28 and 6 had 22; females 18–27 (mode 25): of 40 combs 1 had 18 teeth (malformed), 1 had 21, 2 had 22, 8 had 24, 14 had 25, 12 had 26, and 2 had 27 (85 % of combs with 24–26 teeth). The number of denticle subrows on the pedipalp fingers of males was not significantly different from that of females. The mean subrow count for movable fingers was significantly higher than that for fixed fingers (P = 0.005, paired t-test, n = 62). Of 62 fixed fingers (sexes pooled), there were 1/62 (1.6 %) with 2, 6 and 9 subrows each (anomalous fusions), 2/62 (3.2 %) with 12, 46/62 (74.2 %) with 13 subrows, and 11/62 (17.7 %) with 14; of 62 movable fingers (sexes pooled), there were 1/62 (1.6 %) with 11 and 12 subrows each, 28/62 (45 %) with 13 subrows, and 32/62 (51.6 %) with 14 subrows.

Distribution ( Figs. 65–66 ). All documented records are from the limestone massif of Jabal Akhdar ( Fig. 64 ), at high elevation (> 1,850 m a.s.l.) in the eastern section of the western Al Hajar mountain ranges (Al Hajar Al Gharbi) of northern Oman. Several collections were made from Jabal Shams, the highest peak of Jabal Akhdar. The species may be endemic to these mountains.

Ecology. This is a rupicolous species, found at night by ultraviolet detection in rocky wadis and steep slopes of ravines littered with massive boulders on Jabal Akhdar. The areas where scorpions were observed were relatively sheltered, and none were taken from the open, exposed plateau. The terrain was well vegetated with trees and shrubs ( Fig. 64 ). The elevation range of the collections (1,850 –2,150 m) places this species in the upper Sideroxylon –Olea–Dodonaea zone of vegetation (Mandaville, 1977; Ghazanfar, 1991; Brinkmann et al., 2009), just below the transition to Juniperus excelsa woodland (Gardner & Fisher, 1996). Adult H. saxinatans were observed in ambush positions resting inverted on overhanging surfaces of boulders. Some occupied more protected sites in fissures of cracked boulders, and younger individuals were also found perched on tree trunks. At rest, the metasoma was held coiled to one side, and the pedipalps were retracted in a triangular stance with finger tips touching or intersecting. When disturbed, the animals escaped by gliding swiftly over rock surfaces. Other scorpion species collected from the same areas were Compsobuthus maindroni (Kraepelin, 1900) , Babycurus exquisitus Lowe, 2000 , Hottentotta jayakari (Pocock, 1895) , Nebo omanensis Francke, 1980 , and Orthochirus glabrifrons (Kraepelin, 1903) .

Figures

Figures 27–30: H. saxinatans, sp. nov., habitus, 27–28, holotype male; 29–30, paratype female. 27, 29. Dorsal aspect. 28, 30. Ventral aspect. Scale bar: 10 mm.

Figures 31–37: H. saxinatans, sp. nov., holotype male. 31. Carapace and tergites I–II, dorsal aspect. 32–33, right chelicera. 32. Dorsal aspect. 33. Ventral aspect. 34–35, right basitarsus and telotarsus III. 34. Ventral aspect. 35. Retrolateral aspect. 36–37, metasoma and telson. 36. Right lateral aspect. 37. Ventral aspect. Scale bar: 31: 2.75 mm; 32–33: 2 mm; 34–35: 1.3 mm; 36–37: 5.5 mm.

Figures 38–46: H. saxinatans, sp. nov., 38–45, holotype male; 46, paratype female. 38. Right pedipalp femur, dorsal aspect. 39. Right pedipalp patella, dorsal aspect. 40. Right pedipalp patella, external aspect. 41. Right pedipalp chela, external aspect. 42. Right pedipalp chela, ventral aspect. 43–44. Right hemispermatophore, lobes at base of flagellum. 43. Convex aspect. 44. Inner aspect. 45. Left male pectine, ventral aspect. 46. Left female pectine ventral aspect. Scale bar: 38–42, 45–46: 2 mm; 43–44: 0.68 mm.

Figures 47–52: H. saxinatans, sp. nov., trichobothrial map, holotype male. 47. Right pedipalp femur, dorsal aspect. 48. Right pedipalp femur, proximal internal aspect. 49. Right pedipalp patella, dorsal aspect. 50. Right pedipalp patella, external aspect. 51. Right pedipalp chela, external aspect. 52. Right pedipalp chela, ventral aspect. Trichobothrial notation after Vachon (1974).

Figures 53–56: Pedipalp finger dentition of new Hottentotta species. 53–54, H. pellucidus, sp. nov., holotype male. 55–56, H. saxinatans, sp. nov., holotype male. 53, 55: right fixed finger, ventral aspect. 54, 56: right movable finger, dorsal aspect. Scale bar: 1 mm. Images acquired under UV fluorescence.

Figures 57–64: In vivo habitus and habitats of new Hottentotta species in Oman. 57–59. H. pellucidus, sp. nov. 57–58. Paratype male. 59. Paratype female. 60. H. saxinatans, sp. nov., paratype female. 61–63. Shir Plateau, Jabal Bani Jabir, type locality of H. pellucidus. 61–62. Terrain photos showing extensive fields of loose rock. 63. Prehistoric tower tomb constructed from broken rock.64. Jabal Shams, type locality of H. saxinatans.

Figures 65–66: Maps showing collection sites of new species of Hottentotta in northern Oman. 65. Records plotted on larger scale terrain and elevation map of southeast Arabia with geopolitical borders. 66. Records plotted on color topographic map of northern Oman showing locations in the Al Hajar mountain ranges. Magenta circles: H. pellucidus, sp. nov.; red circles: H. saxinatans, sp. nov. The isolated record of H. pellucidus at Muscat may be spurious.