Mesobuthus songi, Lourenço, Wilson R., Qi, Jian-Xin & Zhu, Ming-Sheng, 2005

Lourenço, Wilson R., Qi, Jian-Xin & Zhu, Ming-Sheng, 2005, Description of two new species of scorpions from China (Tibet) belonging to the genera Mesobuthus Vachon (Buthidae) and Heterometrus Ehrenberg (Scorpionidae), Zootaxa 985, pp. 1-16 : 3-6

Mesobuthus songi sp. n. ( Figs. 1–17 )

Type material: Male holotype, 9 male and 9 female paratypes. China, Tibet, south region of Pulan, low valley of the river Kongque He, near to the border with Nepal, VII/1931 (Collector unknown). Male holotype, 7 male and 8 female paratypes deposited in the Muséum national dHistoire naturelle, Paris . 2 male and 1 female paratypes deposited in Hebei University, Baoding, China.

Etymology: Patronym in honour of Prof. Daxiang Song of the Chinese Academy of Sciences, for his contribution to the arachnological studies in China.

Diagnosis: Scorpions of moderate to large size, with respect to the genus; males reaching 66 mm and females 68 mm in total length. General coloration reddish­yellow to reddish­brown with blackish zones on the carinae of the body. Carinae and granulations strongly marked on carapace, tergites and metasomal segments. Pectinal tooth count 31 to 34 in males and 27 to 29 in females. Very intense setation on body and pedipalps. Trichobothrial pattern of type A, orthobothriotaxic; dorsal trichobothria of femur arranged in (beta) configuration ( Vachon, 1974, 1975).

Relationships: Mesobuthus songi sp. n. is undoubtedly associated with the Mesobuthus tamulus (Fabricius, 1798) group of species. It can, however, be distinguished from other species of this group, and in particular from Mesobuthus tamulus gangeticus ( Pocock, 1900) , by the following characters:

(i) smaller size; 66 and 68 mm in total length against 71 and 76 mm for Mesobuthus tamulus gangeticus , (ii) considerably dasher coloration; Mesobuthus tamulus gangeticus is yellowish to reddish­yellow, (iii) more marked granulation and carinae on carapace, tergites, and especially on the metasomal segments, (iv). Body and pedipalps covered with very intense setation; setation is only moderate in Mesobuthus tamulus gangeticus .

Description based on male holotype and one female paratype. Measurements in Table I.

TABLE I. Morphometric values (in mm) of the ɗ holotype and Ψ paratype of Mesobuthus songi sp. n., ɗ holotype of Heterometrus tibetanus sp. n. and ɗ holotype of Heterometrus nepalensis Kovařík.

Coloration. Basically reddish­brown with some slightly paler zones on venter, pedipalps and legs. Prosoma: carapace reddish­brown, with blackish carinae; eyes surrounded by black pigment. Mesosoma: reddish­brown in males and brownish in females. Metasoma: segments I to IV reddish­yellow; segment V and telson dark reddish; aculeus reddish at the base and blackish on its extremity. Venter yellowish to reddish­yellow, except for the carinae of sternite VII which is blackish. Chelicerae yellowish with variegated spots; fingers yellowish with blackish teeth. Pedipalps yellowish with variegated spots on patella and chela; fingers of chela with the oblique rows of granules dark reddish­brown. Legs yellowish without spots.

Morphology. Carapace strongly granular; anterior margin with a weak median concavity; carinae strong; anterior median, central median and posterior median carinae strongly granular; furrows moderate. Median ocular tubercle slightly anterior to the centre of carapace; median eyes small, separated by almost three ocular diameters; three pairs of lateral eyes. Sternum triangular and wide at the base; longer than wide. Mesosoma: tergites strongly granular; three longitudinal carinae strongly crenulate in all tergites; tergite VII pentacarinate. Venter: genital operculum divided longitudinally; each plate semi­oval in shape. Pectines: pectinal tooth count 31– 31 in the male holotype (see variation on diagnosis); middle basal lamella of the pectines not dilated in either sex. Sternites with minute granulation laterally; spiracles strongly elongated; four moderate carinae on sternite VII; other sternites without carinae, with only two moderate furrows; setation is strong on the posterior edge of the sternites. Metasoma: segments I to IV with 10 strongly crenulate carinae; segment V with 5 strongly crenulate carinae; all segments have a dorsal depression which is weakly granulated. Intercarinal spaces strongly granular, granulation increasing from segment I to segment V. Telson smooth dorsally and strongly granular latero­ventrally; more marked in females; aculeus shorter than the vesicle, and moderately curved subaculear tooth vestigial in males, absent in females. Cheliceral dentition as defined by Vachon (1963) for the family Buthidae ; movable finger with the external distal tooth slightly shorter than the internal distal tooth, and the basal teeth strongly reduced but not fused; ventral aspect of both finger and manus covered with setae. Pedipalps: femur pentacarinate; patella with weakly marked carinae; chela smooth without carinae; tegument from weakly granular to almost smooth; all three segments covered with an intense setation. Fixed and movable fingers with 13 oblique rows of granules in males and females; internal and external accessory granules present; distal extremity of movable fingers with four granules. Legs: tarsus ventrally with two longitudinal rows of 6/9 spines. Tibial spurs present on legs III and IV, strong; prolateral and retrolateral spurs present in all legs. Trichobothriotaxy: Trichobothrial pattern of Type A, orthobothriotaxic as defined by Vachon (1974). Dorsal trichobothria of femur arranged in (beta) configuration ( Vachon, 1975).

Figures

FIGURE 1. Mesobuthus songi sp. n., male holotype, dorsal aspect. Total length 65.9 mm. Scale = 4 mm.

FIGURE 2. Mesobuthus songi sp. n., female paratype, dorsal aspect. Total length 67.8 mm. Scale = 4 mm.

FIGURES 3 – 10. Mesobuthus songi sp. n. 3 – 9. Male holotype, 10. Female paratype. 3. Carapace, dorsal aspect. 4. Lateral ocular region, in detail, dorsal aspect. 5. Disposition of granulations on the dentate margins of the pedipalp chela movable finger, dorsal aspect. 6 – 7. Chelicera (6, dorsal, 7, ventral aspect). 8 – 9. Metasomal segment V (8, ventral, 9, lateral aspect). 10. Sternum, genital operculum and pecten, ventral aspect. Scales = 2 mm.

FIGURES 11 – 17. Mesobuthus songi sp. n., trichobothrial pattern. 11 – 15. Male holotype, 16 – 17 Female paratype. 11. Chela, external aspect. 12. Fixed finger, dorsal aspect. 13 – 14. Patella (13, dorsal, 14, external aspect). 15. Femur, dorsal aspect. 16 – 17. Chela (16, dorso­external, 17, ventrointernal aspect). Scales = 2 mm.