Compsobuthus arabicus Levy, Amitai & Shulov, 1973

Kovařík, František, Lowe, Graeme, Stockmann, Mark & Šťáhlavský, František, 2020, Notes on Compsobuthus: redescription of C. arabicus Levy et al., 1973 from Arabia, and description of two new species from North Africa (Scorpiones: Buthidae), Euscorpius 298, pp. 1-40 : 3-23

Compsobuthus arabicus Levy, Amitai & Shulov, 1973

( Figures 1–63 , 65–109 , 216–218 , Tables 1–2 , 4 )

Compsobuthus arabicus Levy, Amitai & Shulov, 1973: 122– 124 , figs. 17–20; Fet & Lowe, 2000: 125 (complete reference list until 1998); Tigar & Osborne, 1999: 174, 180, tab. 2; Lowe, 2001: 172; Fet et al., 2003: 3; KovařÍk, 2003: 89 (?); Hendrixson, 2006: 62–64, figs. 10, 13; Lowe, 2009: 3; El-Hennawy, 2009: 121 (in part); Lowe, 2010: 36; Lourenço & Duhem, 2012: 124; KovařÍk, 2012: 2; KovařÍk & Ojanguren-Affilastro, 2013: 146–149 (in part); Alqahtani et al., 2019: 22, fig. 2d (?); Lowe et al., 2019: 24, fig. 108.

Compsobuthus acutecarinatus arabicus: KovařÍk, 2001: 80 .

Compsobuthus acutecarinatus: KovařÍk, 2002: 7 (in part).

TYPE LOCALITY AND TYPE DEPOSITORY. Saudi Arabia, Daugha ; BMNH.

TYPE MATERIAL. Saudi Arabia, Daugha [18.9833°N 51.1134°E], 10.I. 1931, 900 ft a.s.l., 1♀ (holotype, 1931.6.2.20, examined), leg. B.S. Thomas, BMNH; Ramlat Mefel [19.9536°N 54.5516°E, 114 m a.s.l.] 1♀ (examined), Khor Mefel [19.9117°N 54.4814°E, 114 m a.s.l.] 1♀ (not examined), X.1945 – II.1946, leg. W. Thesiger, BMNH. Oman: Wadi Mughshin [19.5476°N 54.8835°E, 114 m a.s.l.], 1♀ (not examined), X.1945 – II.1946, leg. W. Thesiger, BMNH.

REMARKS. Locality coordinates of type material cited above (in square brackets) were obtained from maps published by the collectors ( Thomas, 1931; Thesiger, 1946). Two paratype localities of Thesiger cited as ‘Ramlat Enfel’ and ‘Khor Enfel’ in the original description of Levy et al. (1973) were misspelt. In fact, Thesiger (1946) indicated on his map the localities Ramlat Mefel and Khor Mefel along the path of his travels. These two sites are near each other, positioned within the dunes of the Rub’ al-Khali in southeastern Saudi Arabia, close to the Oman border. Errors may have been due to misreading of labels, and were duplicated in subsequent listings ( Fet & Lowe, 2000; El-Hennawy, 1992, 2009; Vachon, 1979; Alqahtani et al. 2019). The other paratype locality cited by Levy et al. (1973), ‘Wadi Mughhin’, is actually Wadi Mughshin ( Thesiger, 1946) (also spelt ‘Wadi Muqshin’), as suggested by Fet & Lowe (2000). KovařÍk (2003) listed C. arabicus (1 ♂, immature) from 150 km SSW of Riyadh, central Saudi Arabia (see also KovařÍk, 2002: 7). We have not re-examined this specimen to confirm its validity. Alqahtani et al. (2019) reported C. arabicus from southwestern Saudi Arabia, although we have not directly confirmed this record.

OTHER MATERIAL EXAMINED. Oman: Mintirib, 22°26'N 58°48'E, 268 m a.s.l., 13.II.1980, wadi, Oman Eastern Sands Project, 1♀, leg. W. Büttiker, NHMB 705.00; Wahiba Sands, 21°57'N 58°53'E, 22.XII.1985, 1♀, leg. M. D. Gallagher, NHMB; Shariq, 22°28'N 58°48'E, 295 m a.s.l., 9.II.1986, Acacia wood, Oman Eastern Sands Project, 1♀, leg. W. Büttiker, NHMB; Yalooni , 19°56'N 56°06'E, 2.XI.1993, 1♀, leg. Cjv, YAL 518, BMNH ; Yalooni, 19°57'N 57°07'E, 154 m a.s.l., 18.XI.1993, inside portacabin, 1♂, leg. M. W. Lawrence, NHMB; Wahiba Sands, 22°10.68'N 58°51.16'E, 90 m a.s.l., 7.X.1993, 19:00 h, UV detection, base of shrub, nr base of linear dunes with vegetation, 2♂, leg. G. Lowe, M.D. Gallagher, N. Wood and S. Prakash, NHMB; Yalooni, Jiddat Al Harasis , 19°56'N 57°05'E, 154 m a.s.l., 14.III.1994, 22:00 h, on sand and stones, 1♀, leg. M.D. Gallagher, MDG 8561, GLPC ; Yalooni, 19°56'N 57°05'E, 154 m a.s.l., 15.III.1994, 22:00–23:00 h, UV detection, still on plant remains, under Acacia bush on sand mound, clear sky, new moon, slight breeze, 1♀, leg. M. D. Gallagher, MDG 8564.5, NHMB; W of Ghabah , 21°23.89'N 57°09.56'E, 185 m a.s.l., 5.X.1994, UV detection on sand, sandy wadi with dunes and scrub adjacent to sabkha, windy, 2♂, leg. G. Lowe and M. D. Gallagher, MCZ ; NW of Ghabah , 21°31.55'N 57°16.49'E, 180 m a.s.l., 5.X.1994, UV detection in small wadi, flat gravel plain, 1♂ 1♀, leg. G. Lowe and M. D. Gallagher, ONHM ; Ramlat As Sahmah, 20°06.6'N 55°58.89'E, 155 m a.s.l., 7.X.1994, UV detection on sand, low dune slope, vegetated hummocks with Calligonum , 1♂, leg. G. Lowe and M. D. Gallagher, NHMB; S of Ghabah , 21°20.99'N 57°14.52'E, 180 m a.s.l., 8.X.1994, UV detection in sandy wadi with bushes, 1♂, leg. G. Lowe and M. D. Gallagher, GLPC ; between Ghabah & Adam , 22°09.54'N 57°30.16'E, 250 m a.s.l., 16.IX.1995, 22:00-23:00 h, UV detection, sandy vegetated wadi in open gravel plain, trees and bushes, 1♂, leg. G. Lowe and J. Dundon, ONHM ; nr Wadi Andam, road south of Sinaw , 21°19.35'N 58°15.55'E, 90 m a.s.l., 19.IX.1995, 23:00 h, UV detection on soft sand at base of shrubs, sandy soil mixed with firmer soil, gravel and small stones, patch of vegetation with shrubs and small trees, scorpions run quickly on sand when exposed to UV light, 1♀, leg. G. Lowe and M. D. Gallagher, NHMB; nr Wadi Andam, road south of Sinaw , 21°19.48'N 58°15.24'E, 90 m a.s.l., 19.IX.1995, 23:30 h, UV detection on soft sand at base of shrubs, sandy soil mixed with firmer soil, gravel and small stones, patch of vegetation with shrubs and small trees, 1♂, leg. G. Lowe and M. D. Gallagher, NHMB; 10 km N Adam , 22°29.66'N 57°33'E, 300 m a.s.l., 23.X.1995, 22:45 h, in the open on sandy or gritty ground in a well vegetated small wadi, 1♀, leg. J. Dundon, GLPC ; 55 km NW Ibri , 23°36.5'N 56°05.33'E, 290 m a.s.l., 22.XI.1995, 19:30-20:30 h, area of low sand dunes, scorpions found at entrance to burrows, 2♂, leg. J. Dundon 106, NMPC ; 55 km NW Ibri, 23°35.5'N 56°04.33'E, 290 m a.s.l. 22.XI.1995, 20:30–21:30 h, area of low sand dunes, scorpions found at entrance to burrows, 1♂, leg. J. Dundon 107, NHMB; between Qarn Alan and Ghabah North , 21°22.03'N 57°05.47'E, 150 m a.s.l., 21.II.1996, UV detection on coarse grit on top of dusty alluvium, in shallow depression, Acacia ehrenbergiana with sand mounds at base, 1♂ 2♀ 1 juv., leg. M. D. Gallagher, MDG 8755 , NHMB; 30 km S. of Adam, 22°05.9'N 57°31.12'E, 19.III.1996, 23:30-01:00 h, in sandy wadi, 2♀, leg. J. Dundon 118, NHMB; Ghneem (= Saiwan ), 20°53.75'N 57°38.78'E, 17.IV.1997, 19:00-22:00 h, open sand between gravel ridges of small hills, 1♂, leg. M. D. Gallagher, I. D& M. Harrison and J. Peterson, MDG 8857, NHMB; Yalooni, 19°56'N 57°06'E, 1.VII.1997, Yalooni camp, 1♀, leg. S. Brend, YAL 617 , NHMB; Ramlat Muqshin, 19°46.3'N 55°07.1'E, 100 m a.s.l., 29.XI.1997, on small dune sand, most under cover of scrub bushes, new moon, 4♀, leg. M. D. Gallagher and I. D. Harrison, MDG 8905 , NHMB; Al Mushash , 19°39.5'N 54°00'E, 129 m a.s.l., 1.XII.1997, under rubbish on sand, 1♀, leg. M. D. Gallagher, MDG 8910, USNM ; Wadi Qitbit , 19°07'N 54°31'E, 100 m a.s.l., 6.XII.1997, dry sandy desert with shrubs and small trees, strong new moon, no breeze, 1♀, leg. I. D. Harrison and M. D. Gallagher, MDG 8923, ONHM ; 15 km NNE of Fasad , 18°45.2'N 53°08.9'E, 290 m a.s.l., 29-30.I.1998, in high dunes and lower slopes, 1♂ 1♀, leg. M. D. Gallagher and J. N. Barnes, MDG 8940, GLPC ; N. of Fasad, Empty Quarter , 18°40.3'N 53°04.4'E, 31.I.1998, under stone on level sand between dunes, 1♀, leg. J. N. Barnes, NHMB; E. of Ghabah Rest House , 21°22.8'N 57°15.2'E, 130 m a.s.l., 3.I.1999, 17:45 h, rocky plain with coarse grit, under rock, 1♀, leg. A. Winkler, ZSMC ; Wadi Qit Bit , 19°08.11'N 54°31.08'E, 212 m a.s.l., 18.XII.2001, 16:30-17:45 h, day collection, under oil barrel, 2♀, leg. A. Winkler, ZSMC ; Wadi Qit Bit , 19°09.33'N 54°30.47'E, 210 m a.s.l., 18.XII.2001, 20:00-21:00 h, UV detection, sandy dunes, near spring, on sand between shrubs, 1♂, leg. A. Winkler, ZSMC ; W of Wahiba sands, 22.02990°N 58.18490°E, IX.2016, 1♂ (captive bred, 1801), 1♀, leg. M. Stockmann, FKCP ; Al Wasil , 22.49143°N 58.71513°E ( Fig. 107 ), XI.2017, dry dune area, sandy vegetated areas, UV detection at base of small shrubs, 1♂ (captive bred), 2♀, leg. M. Stockmann, FKCP ; SW of Wahiba, 21°19.35'N 58°15.55'E, XI.2017, nr Wadi Andam , sandy area with small shrubs, 2♀, leg. M. Stockmann, FKCP ; Dhofar Province, 236 km N Salalah, Wadi Qitbit , 19°9'20"N 54°30'27"E, 160 m a.s.l., 16-17.I.2018, 1♀, leg. P. KabÁtek, FKCP ; E of Aydam , 17.888736°N 53.066401°E ( Fig. 108 ), X.2019, 1♂ (No. 1789), leg. M. Stockmann. United Arab Emirates: Bada Zaid , Abu Dhabi, 24°15'N 54°28'E, 20. V.1972, 1♀, leg. D. J. G. Williams, RS 6512, MNHN ; Madinet Zayed , 23.68167°N 53.69861°E, 14.X.1993, 1♂ 1♀, leg. A. Saji, TERC ; Al Khatim , 24.16849°N 54.98412°E, 17.XI.1993, 1♂, leg. A. Saji, TERC ; env. Lahhab , Dubai, 24°59'00.7"N 55°39'36.2"E, 151 m a.s.l., 21.XI.2006, 1♂, leg. J. Batelka and H. Pinda, FKCP .

DIAGNOSIS. Total length 20–29 mm. Sexual dimorphism minor, pedipalp fingers straight in females, almost straight or weakly scalloped in males, male chela with broader manus, chela L/W ratio: ♂ 4.70–5.47, ♀ 5.61–6.55; metasomal segment proportions similar in both sexes. Base color uniform yellow. Carapace, tergites, pedipalps and legs densely, finely granular or shagreened. Anterior margin of carapace bearing 8–10 symmetrically distributed spinules. Pedipalp femur L/ Carapace L ratio: 0.76–0.87. Movable finger of pedipalp chela with 7–8 rows of granules, without external accessory denticles, with 9 internal accessory granules (‘ acutecarinatus ’ group of Levy & Amitai, 1980). Manus of pedipalp chela shorter than fixed finger. Pedipalp chela L/movable finger L ratio: ♂ 1.37– 1.47, ♀ 1.28–1.41. Metasoma I with 10 carinae, II–IV with 8 carinae. Median lateral carinae of segment II replaced by isolated granules that may coalesce into carinae posteriorly. All metasomal segments longer than wide; metasoma L/W ratios: III 1.63–1.82, IV 1.93–2.19, V 2.37–2.80. Metasoma V W/D ratio: 1.07–1.17. Ventral intercarinal surfaces of metasoma lacking macrosetae. Pectine teeth: ♂ 13–16, ♀ 9–15. Pectine L/ Metasoma V W ratio: ♂ 1.40–1.88, ♀ 1.38–1.69. Sternites and metasoma granulated. Sternite VI with 4 weak carinae, VII with 4 crenulate carinae. Telson elongate, aculeus shorter than vesicle. Subaculear tubercle moderate.

DESCRIPTION. Total length 21–29 mm in both sexes. The habitus is shown in Figs. 1–2 , 18–21 , 65–68 , 103–104 . Trichobothriotaxy of pedipalps is shown in Figs. 10–14, 16 , 39–42, 44–45 , 78–82 .

Sexual dimorphism. Sex differences are minor, females with straight pedipalp fingers ( Figs. 11 , 48 ), male fingers nearly straight, weakly undulate proximally with small gap ( Figs. 39 , 81 ). No sex differences in proportions of metasomal segments. Females with shorter pectines, smaller pectine teeth, larger genital opercula.

Coloration ( Figs. 1–68 ). Base color is uniform yellow. Variable dark pigmentation may occur on the interocular triangle of carapace, pedipalp femur and patella, legs, and metasomal carinae. Metasoma V can have weak fuscosity that is barely visible.

Carapace and mesosoma ( Figs. 7–8 , 22–27 ). The entire surface of the carapace is densely covered by granules of different sizes.The carinae are moderately to strongly developed and granular. The anterior margin of the carapace is weakly concave medially, and bears 8–10 symmetrically distributed spinules (macrosetae). The tergites are strongly granulated. Tergites I–VI are tricarinate, with strong, denticulate median and lateral carinae. Each carina terminates in a spiniform process that in the lateral carinae extends well past the posterior margin of the tergite. Tergite VII is pentacarinate, with lateral pairs of carinae strong, serratocrenulate, median pairs moderate, crenulate; median carina is weak and confined to the anterior half of the segment. Pectinal tooth counts: ♂ 13–16 (8×13, 9×14, 12×15, 4×16; N = 33 combs), ♀ 10–15 (1×10, 2×11, 17×12, 17×13, 14×14, 1×15; N = 52 combs). The pectine marginal tips extend barely to the posterior margin of sternite III in females, and to half the length of sternite IV in males (not past the distal end of coxa IV). The pectines have 3 marginal lamellae and 6–8 middle lamellae. The lamellae bear numerous dark setae, and each fulcrum bears 2–3 dark setae. Sternites are finely granulated or shagreened, more strongly so on lateral areas of sternites III–VI which have smoother medial areas, and uniformly granulated on sternite VII. The posterior areas of sternites lack a broad glabrous patch. Sternites VI–VII bear 4 crenulate carinae, weakly developed on VI and well developed on VII. Other sternites bear one pair of weak posterior carinae on the medial side of the spiracles.

Metasoma and telson ( Figs. 3–5 , 55–63 ). Metasomal segment I with 10 carinae, II–IV with 8 carinae, and V with five carinae. Median lateral carinae of metasoma II are indicated by isolated granules that may coalesce into carinae posteriorly. All segments sparsely setose and densely granulate. Accessory rows of granules may be present on dorsal surfaces of segments as well as on the ventral surface of segment V. The telson is elongate, with aculeus slightly shorter than vesicle, and a moderately developed subaculear tubercle.

Pedipalps ( Figs. 10–17 , 38–54 ). The pedipalps are finely granulated and sparsely hirsute. The femur bears 5 carinae, the patella 7 granular carinae, the chela 7 carinae. The movable and fixed fingers bear 7–9 rows of granules, without external accessory granules, with 9 internal accessory granules on both fingers. Pedipalp chela L/W ratio: ♂ 4.70–5.47, ♀ 5.61–6.55. Manus of chela shorter than fixed finger. Pedipalp chela L/ movable finger L ratio: ♂ 1.37–1.47, ♀ 1.28–1.41.

Legs ( Figs. 9 , 30–37 ). Legs III–IV bear small tibial spurs. Retrolateral and prolateral pedal spurs are present on all legs. The tarsomeres bear two rows of macrosetae on the ventral surface and several macrosetae on the other surfaces. Sparse bristlecombs of 3–5 setae are developed on basitarsi of legs I–III. The femur bears 4 carinae, the patella 4–6 carinae. The femur and patella bear only solitary macrosetae and are granulated on prolateral surfaces, weakly granulated or smooth on retrolateral surfaces. Tarsal ungues strongly elongated, curved.

Hemispermatophore ( Figs. 72–73 ). Flagelliform, elongate and slender. Flagellum separated from external lobe. Capsule region with 4 lobes at base of flagellum. Posterior lobe longest, triangular, apically rounded, median lobe shortest, apically truncate, anterior lobe acuminate with long thin terminus. Basal lobe is strong with a broad base and sharp, falcate hook. Measurements. Table 1 lists measurements for representative male and female specimens. Morphometric variation is summarized in Table 2 and is plotted in Figs 85–102 . The plots indicate that two male samples taken from populations in the United Arab Emirates are not morphometrically separable from Oman populations ( Figs. 85–93 ). They also indicate that the female holotype from Saudi Arabia is not morphometrically separable from Oman populations ( Figs. 94–102 ). We therefore consider all of these populations to represent a single species exhibiting continuous variation across its geographic range ( Fig. 109 ).

AFFINITIES. C. arabicus is one of the smaller members of the ‘ acutecarinatus ’ group (Levy & Amitai, 1980), and it has a correspondingly low pectinal tooth count (10–15 in females). Other Compsobuthus species from Oman in the ‘ acutecarinatus ’ group have higher numbers of pectine teeth. In females, C. acutecarinatus (Simon, 1882) has 20–27 teeth, C. maindroni (Kraepelin, 1901) has 19–21, C. nematodactylus Lowe, 2009 has 28–33 and C. polisi Lowe, 2001 has 16–20. In Oman, C. polisi is a small species (adults 22–35 mm) that is outwardly similar to C. arabicus . It can be differentiated by the presence of numerous short, macrosetae on ventral intercarinal surfaces of the metasoma. It differs morphometrically in having somewhat more elongated (higher L/W ratio) metasomal segments III and IV ( Figs. 86 , 95 ) and pedipalp femur and patella ( Figs. 91 , 100 ), although there is overlap in some of the ratios. Metasomal segments of C. polisi tend to be deeper than those of C. arabicus , as indicated by lower L/D ratios ( Figs. 87, 89 , 96 ) and W/D ratio ( Figs. 93 , 102 ) (see Fig. 64 vs. Figs. 55–63 ). In males, C. polisi is separable from C. arabicus by having pedipalp chelae more slender with longer fingers ( Fig. 92 ). Geographically, C. polisi is distributed more along the coastal regions, whereas C. arabicus is ranges further inland in major aeolian dunes (Wahiba/ Sharqiya Sands, Rub’ al- Khali). Two other similarly small species belonging to the ‘ acutecarinatus ’ group are C. pallidus Hendrixson, 2006 , and C. setosus Hendrixson, 2006 , from northern and central Saudi Arabia, respectively. The former can be differentiated by having 10–11 granule rows on the pedipalp fingers, and the latter by the presence of numerous ventral intercarinal setae on the metasoma and sternite VII ( Hendrixson, 2006).

ECOLOGY ( Figs. 107–109 ). C. arabicus is a psammophilic species found in the expansive aeolian dune systems of Ramlat al-Wahiba and Rub’ al-Khali. It is not an ultrapsammophile, as it is also distributed over other interior regions of Oman where sand dunes intermingle with silty, gravelly or stony substrates, such as the plateau of Jiddat al Harasis ( Fig. 109 ). Like other arenicolous desert scorpions, it excavates burrows near the bases of vegetation and emerges at night to take ambush positions near burrow entrances. Tigar & Osborne (1999) examined the relationship between the surface activity of a diverse assemblage of nocturnal arthropods and the lunar cycle in an area near Abu Dhabi. Analysis of data pooled from all surveyed taxa revealed significantly more pitfall trap captures on a new moon, than on a full moon. For C. arabicus , there were 2 records on new moon, and none on full moon. However, this sample is too small to test the hypothesis of moon avoidance for this one species. We have observed surface activity of C. arabicus on both moonlit and dark nights.Among 16 independent records of nocturnal surface activity, 12 nights (75%) were 5 days or less from a new moon. This is consistent with the hypothesis, but is not conclusive because there is likely to be an inherent sampling bias due to collectors preferring to search for scorpions by UV detection on darker nights. Other scorpions that were observed together with C. arabicus in sandy habitats include: Androctonus crassicauda (Olivier, 1807) , Apistobuthus pterygocercus Finnegan, 1932 , Buthacus nigroaculeatus Levy, Amitai & Shulov, 1973 , Picobuthus dundoni Lowe, 2010 , P. wahibaensis Lowe, 2010 , Vachoniolus gallagheri Lowe, 2010 and V. globimanus Levy, Amitai & Shulov, 1973 .

LIFE HISTORY ( Figs. 105–106 ). The following data were obtained from captive rearing in a temperate climate. In a gravid female collected in IX–XI.2016, parturition was recorded in VII.2017, with litter sizes of 7 juveniles. Only two individuals were reared to maturity, at sixth (♂) and seventh (♀) instars. In two gravid females collected in XI.2017, parturition was recorded in VI.2018, with litter sizes of 7 and 10 juveniles. These were reared to maturity by VI–VIII.2018 and IX–XI.2018, at fifth (♂) and sixth (♀) instars.

Figures

Figure 65. Compsobuthus arabicus. Male, Wahiba Sands (22°10.68'N 58°51.16'E, 7.X.1993), dorsal habitus. Color image with cuticular surface detail highlighted digitally by UV fluorescence. Scale bar: 5 mm.

Figure 66. Compsobuthus arabicus. Male, Wahiba Sands (22°10.68'N 58°51.16'E, 7.X.1993), ventral habitus. Color image with cuticular surface detail highlighted digitally by UV fluorescence. Scale bar: 5 mm.

Figure 67. Compsobuthus arabicus. Female, 30 km S of Adam (22°05.9'N 57°31.12'E, 19.III.1996), dorsal habitus. Color image with cuticular surface detail highlighted digitally by UV fluorescence. Scale bar: 5 mm.

Figure 68. Compsobuthus arabicus. Female, 30 km S of Adam (22°05.9'N 57°31.12'E, 19.III.1996), ventral habitus.Color image with cuticular surface detail highlighted digitally by UV fluorescence. Scale bar: 5 mm.

Figures 69–77: Compsobuthus arabicus. Figure 69. Carapace and tergites I–II. Figures 70–71. Right chelicera, dorsal (70) and ventral (71) views. Figures 72–73. Right hemispermatophore, capsule region, convex (72) and anterior (73) views. Figures 74–75. Metasoma and telson, lateral (74) and ventral (75) aspects. Figures 76–77. Right leg III, telotarsus and basitarsus, retrolateral view (76), and telotarsus, ventral view (77). Scale bar: 5 mm (69); 1 mm (70–71); 0.68 mm (72–73); 3 mm (74–75); 1.175 mm (76); 0.84 mm (77). Males from: 55 km NW of Ibra (23°36.5'N 56°05.33'E, 22.XI.1995) (69, 74–75); W of Ghabah (21°23.89'N 57°09.56'E, 5.X.1994) (70–71, 76–77); 15 km NNE of Fasad (18°45.2'N 53°08.9'E, 29-30.I.1998) (72–73).

Figures 78–84: Compsobuthus arabicus. Figures 78–82. Right pedipalp, femur dorsal (78), patella dorsal (79), external (80); chela external (81), ventral (82). Figures 83–84. Left pectine, male (83), female (84). Scale bar: 1 mm. Male from 55 km NW of Ibra (23°36.5'N 56°05.33'E, 22.XI.1995) (78–83); female from 10 km N of Adam (22°29.66'N 57°33'E, 23.X.1995) (84).

Figures 85–93: Scatter plots showing variation in male morphometric ratios of Compsobuthus arabicus, and C. polisi Lowe, 2001. Metasoma I L/W vs. metasoma II L/W (85), metasoma III L/W vs. metasoma IV L/W (86), metasoma V L/D vs. metasoma V L/W (87), metasoma I L/D vs. metasoma II L/D (88), metasoma III L/D vs. metasoma IV L/D (89), pedipalp femur L/ carapace L vs. Pectine L/ Metasoma V W (90), pedipalp femur L/W vs. pedipalp patella L/W (91), pedipalp movable finger L/ manus ventral L vs. pedipalp chela L/W (92), and metasoma III L/W vs. metasoma V W/D (93). Black circles: C. arabicus samples from Oman; green circles: C. arabicus samples from United Arab Emirates; yellow circles: C. polisi samples (all from Oman).

Figures 94–102: Scatter plots showing variation in female morphometric ratios of Compsobuthus arabicus, and C. polisi. Metasoma I L/W vs. metasoma II L/W (94), metasoma III L/W vs. metasoma IV L/W (95), metasoma V L/D vs. metasoma V L/W (96), metasoma I L/D vs. metasoma II L/D (97), metasoma III L/D vs. metasoma IV L/D (98), pedipalp femur L/ carapace L vs. Pectine L/ Metasoma V W (99), pedipalp femur L/W vs. pedipalp patella L/W (100), pedipalp movable finger L/ manus ventral L vs. pedipalp chela L/W (101), and metasoma III L/W vs. metasoma V W/D (102).. Black circles: C. arabicus samples from Oman; red circle: C. arabicus holotype from Daugha, Saudi Arabia; yellow circles: C. polisi samples (all from Oman).

Figures 103–104. Compsobuthus arabicus, in vivo habitus of females from Oman, W of Wahiba Sands (103), and SW of Wahiba (104).

Figures 105–106. Compsobuthus arabicus, female from Oman, W of Wahiba sands, 22.02990°N 58.18490°E with newborns (105) and juveniles after first ecdysis (106).

Figures 107–108. Compsobuthus arabicus, localities. Figure 107. Oman, W of Wahiba sands. Figure 108. Oman, E of Aydam.

Figure 109. Map showing records of Compsobuthus arabicus Levy, Amitai & Shulov, 1973, in the southeastern Arabian Peninsula. The holotype and paratype localities are indicated by arrows. Plotted records were confirmed by examination of materials, with the exception of two of the three paratype localities of Thesiger.

Figures 1–9: Compsobuthus arabicus Levy, Amitai & Shulov, 1973, holotype female from Daugha, Saudi Arabia. Figures 1–2. Habitus in dorsal (1) and ventral (2) views. Scale bar: 10 mm. Figures 3–5. Metasoma and telson in lateral (3), dorsal (4) and ventral (5) views. Scale bar: 5 mm. Figure 6. Telson in lateral view. Figure 7. Carapace and tergites I–IV. Figure 8. Posterior coxosternal area, sternum, genital opercula, pectines and sternites III–IV. Figure 9. Right legs III–IV, tarsal segments, retrolateral aspect.

Figures 10–17: Compsobuthus arabicus, holotype female, right pedipalp. Figures 10–12. Chela in dorsal (10), external (11) and ventrointernal (12) views. Figures 13–15. Patella in dorsal (13), external (14) and ventral (15) views. Figure 16. Trochanter and femur, dorsal view. Figure 17. Movable finger, dorsal view showing dentition. White circles: trichobothrial positions (Figures 10–14, 16).

Figures 18–22: Compsobuthus arabicus, from Oman, habitus. Figures 18–19. Male from SW of Wahiba, 21°19.35'N 58°15.55'E, dorsal (18) and ventral (19) views. Figures 20–21. Female from Dhofar Province, Wadi Qitbit, 19°9'20"N 54°30'27"E. Scale bar: 10 mm.

Figures 22–37: Figures 22–27: Compsobuthus arabicus, prosoma and mesosoma. Figures 22–23. Male, SW of Wahiba, carapace and tergites I–IV (22), posterior coxosternal area and sternites (23). Figures 24–25. Female, Wadi Qitbit, carapace and tergites I–III (24), posterior coxosternal area and sternite III (25). Figure 26. Female, Oman, W of Wahiba sands (22.02990°N 58.18490°E), posterior coxosternal area and sternites. Figure 27. Female, SW of Wahiba (21°19.35’N 58°15.55’E, XI.2017), posterior coxosternal area and sternites III–IV.Figures 28–29. C. polisi, female paratype from Oman, Wadi Dirif, carapace and tergites I–II (28), posterior coxosternal area and sternite III (29). Figures 30–37: C. arabicus, legs, tibiae and tarsi, retrolateral aspects. Figures 30–33. Male, right legs I–IV. Figures 34–35. Female, SW of Wahiba, left legs III–IV. Figures 36–37. Female, Wadi Qitbit, left legs III–IV.

Figures 38–54: Compsobuthus arabicus, pedipalps. Figures 38–45. Male, SW of Wahiba, chela dorsal (38), external (39) and ventral (40), patella dorsal (41), external (42) and ventral (43), trochanter and femur internal (44), dorsal (45), and ventral (46) views. Figures 47–54. Female, SW of Wahiba, chela dorsal (47), external (48) and ventrointernal (49), patella dorsal (50), external (51) and ventral (52), trochanter and femur dorsointernal (53) and dorsal (54) views. White circles: trichobothrial positions (Figures 38–42, 44–45).

Figures 55–64: Figures 55–63. Compsobuthus arabicus. Figures 55–57. Male, SW of Wahiba, metasoma and telson lateral (55), ventral (56), and dorsal (57) views. Figures 58–60. Female, SW of Wahiba, metasoma and telson lateral (58), ventral (59), and dorsal (60) views. Figures 61–63. Female, Wadi Qitbit, metasoma and telson lateral (61), ventral (62), and dorsal (63) views. Figure 64. C. polisi Lowe, 2001, female paratype from Oman, Wadi Dirif, metasoma and telson lateral view. Scale bar: 10 mm.

Figures 210–224: Mitotic metaphases (210, 213, 216, 219, 222), male postpachytenes (211, 214, 217, 220, 223), and ideograms (212, 215, 218, 221, 224) (y axis: % of the diploid chromosome length, dark grey marks: chromosomes in multivalent association) of Compsobuthus species from Arabia and North Africa. Figure 210. Female of C. acutecarinatus (2n=22). Figures 211–212. Male of C. acutecarinatus (2n=22, 11II). Figures 213–215. Male of C. acutecarinatus (2n=22, 9II+CIV). Figures 216–218. Male of C. arabicus (2n=22, 9II+CIV). Figures 219–221. Male of C. maindroni (2n=22, 11II). Figures 222–224. Male of C. ullrichi sp. n. (2n=22, 9II+CIV).Arrows show chromosomes in multivalent association during postpachytene (214, 217, 223). Scale bar: 10 μm