Tityus stigmurus (Thorell, 1876)

De, Claudio Augusto R., Candido, Denise M., Lucas, Sylvia Marlene & Brescovit, Antonio Domingos, 2009, On the Tityus stigmurus complex (Scorpiones, Buthidae), Zootaxa 1987, pp. 1-38 : 23-29

Tityus stigmurus (Thorell, 1876)

Isometrus stigmurus (Thorell, 1876) : 132–134. Holotype Ψ from Pernambuco, Brazil (deposited in NRS, not examined). Tityus stigmurus . Lourenço & Cloudsley-Thompson, 1999: 154 –156, 158; Fet et al, 2000: 262; Lourenço, 2001: 21 –26, 29, 34; Lourenço, 2002: 37, 153–154, 155, 164; Lourenço, 2003a: 109, 113; Lourenço, 2003b: 427, 432; Lourenço, 2006: 61; Souza et al, 2006: 27 –28, 35; Dias et al, 2006: 707 –709.

Material examined. Brazil, Ceará: Crato, 692m, 7º13’60’’S 39º29’60’’W, X.2004, A. Vasconcellos leg., 1Ψ ( IBSP 3841); Paraíba: Cabaceiras, 319m, 7º1’S 37º27’W, 2004, M.T.L.Duarte leg., 8Ψ ( IBSP 3644); João Pessoa ( Mata do Buraquinho), 7º6’S 34º52’W, 2003, S. C. Dias leg., 1Ψ ( IBSP 3987); Pernambuco: Surubim, 236m, 7º49’60’’S 35º45’W, 18.VIII.2003, S. M. T. Macedo, 1Ψ ( IBSP 3369); Carpina, 151m, 7º50’60’’S 35º15’W, 19.X.2002, Engenho Petribú leg., 3Ψ ( IBSP 2866); Lagoa do Itaenga, 154m, 7º55’S 35º19’60’’W, 25.X.2001, Usina Petribú leg., 1Ψ ( IBSP 2859); Arquipelago de Fernando de Noronha, Ilha de Fernando de Noronha, 3º50’S 32º15’W, 2006, G. Freitas leg., 1Ψ ( IBSP 4683); Bahia: Paulo Afonso, Raso da Catarina, 9º33’– 9º54’S 38º29’– 38º44’W, VII.1982, T. Brazil Nunes leg., 1ɗ ( IBSP –1330); Camaçari, 413m, 10º5’60’’S 42º32’60’’W, VII.1983, T. Brazil Nunes leg., 1ɗ ( IBSP 1481); Jequié, 209m, 13º50’60’’S 40º4’60’’W, 03.II/ 07.VII.2005, L. Boccardo et al leg., (Pitfall in urban area) 1Ψ ( IBSP 4287); Alagoas: Murici, 145m, 9º19’S 35º55’60’’W, 28.I.1989, L. M. Freitas leg., 4Ψ ( IBSP 2025); Rio Largo, 75m, 9º28’60’’S 35º51’W, 27.I.1999, R. Omera leg., 1Ψ ( IBSP 2479); Maceió (Ipióca, Serra da Saudinha), 9º22’S 35º43’W, 04.VI.2005, G. Q. Correia leg., 1Ψ ( IBSP 4602).

Comments. The species T. stigmurus Thorell, 1876 was described as Isometrus stigmurus , and transferred to Tityus by Kraepelin (1899). T. serrulatus and T. stigmurus are very closely related species and due to this close relationship several taxonomical changes have been proposed between them (see T. serrulatus above). The original description was based on two female specimens from Pernambuco, Brazil. Mello-Leitão (1945) first pointed out some differences between the female and male but without precise details and not mentioning which specimens he examined. No further contributions have been proposed to distinguish the sexes since 1945. The male of T. stigmurus is redescribed and the diagnostic differences between the sexes described.

Diagnosis. Male. This species differs from the others of the complex by presence of three dark brown longitudinal stripes on tegites, except by T. aba and T. martinpaechi . Tityus stigmurus can be distinguished from T. aba by a different pattern of pigmentation, with a single longitudinal dark brown stripe on tergites which reaching the VII tergite, carapace with only one triangular dark brown spot on anterior region ( Fig. 16 A–B), smallest number of pectinal teeth (22, 23–24), pedipals slender (length femur=6.5; tibia=7.2; chela=12.5) and smallest total length ( T. stigmurus 60,3–63,8 mm), whereas T. aba has carapace almost entire dark ( Fig. 1 A–B), three longitudinal dark brown stripes on tergites which begin at the posterior edge of the carapace, the lateral ones reaching the VI tergite and the central reaching the VII ( Fig. 1 A–B), a largest number of pectinal teeth (male 25–25, 26–25, 26–27), pedipals stouter (length femur=8.3; tibia=8.7; chela=14.9) and greatest total length ( T. aba 76.5 mm)( Candido et al, 2005). It also differs from T. martinpaechi by a different pattern of pigmentation, with a single longitudinal dark brown stripe on tergites which reaching the VII tergite, carapace with only one triangular dark brown spot on anterior region ( Fig. 16 A–B) and smallest total length, whereas T. martinpaechi has three longitudinal dark brown stripes on tergites which begin at the posterior edge of the carapace, the lateral ones reaching the VI tergite and the central reaching the VII, carapace with some dark brown spots ( Fig. 9 A–B) and greatest total length (male 73,6 mm).

Female. Female pattern of coloration is similar to the male ( Fig. 16 A–D). The main morphological differences are the narrow metasomal segments (female: I=3.3; II=3.3; III=3.3; IV=3.5; V=3.2; male: I=4.8; II=5.0; III=5.0; IV=4.7; V=4.1) and shorter pedipalp segments ( Fig. 17 A–B) (female: femur=5.7; tibia=6.3; chela=11.7; male: femur=6.3; tibia=7.1; chela=12.2) (table 1).

Redescription. Male (IBSP 1330); Coloration basically yellowish, carapace pale yellow, with a dark triangle whose base faces the anterior region ( Fig. 16 B); ocular tubercle dark. Mesosoma with three longitudinal dorsal stripes along the tergites. The central stripe extends from the posterior edge of the carapace to tergite VII while the lateral stripes extend from the posterior edge of carapace to tergite IV; on tergite VII there is a dark brown triangular spot on the anterior margin with the apex orientated backwards in the central region ( Fig. 16 B). Metasomal segments I–IV yellow with dark brown spots on the ventral submedian carinae, segment V yellow with a ventral stain occupying almost all the posterior region ( Fig. 17 C–D). Vesicle yellow, with aculeus reddish-yellow at its base and reddish at its extremity. Ventral surface yellow, chelicerae yellow, extremity of the fingers and teeth reddish. Pedipalps and chela yellow; fingers reddish though distally paler. Legs yellow. Morphology; Carapace: anterior margin with a weak median concavity; median ocular tubercle anterior to centre of the carapace; median eyes separated by more than one ocular diameter; space between median ocular carinae shallow; three pairs of lateral eyes; median ocular carinae moderate with small granules; anterior median furrow moderately deep; posterior furrow narrow, shallow anterioraly deep posteriorly. Prosoma: moderately granular; granulation more intense on anterior region. Tergites weak to moderately granular with some large granules on the posterior region; median carinae present on all tergites, on tergites I and II reduced; on II and IV occupying the distal third; on V and VI occupying the distal half; on tergites III–VI carinae begin bifurcated and finish merged; tergite VII pentacarinate; transversal carinae present on all tergites. Pectines: pectinal teeth 23–24; basal middle lamellae not dilatated. Sternites weakly granular; a smooth and shining slightly expanded triangular zone on the posterior region of sternites III and V ( Fig. 16 B); sternite VI with two small median carinae occupying the distal half; sternite VII with five carinae, of which the two parallel median carinae occupy almost all of the sternite with a small carina between them, the two lateral carinae restricted to the central region. Metasoma: segment I with 10 with complete carinae of which Vsm, Vl, Lim, Lsm and Dl have adjacent granules; II with 8 complete carinae of which Vsm,Vl, Lsm and Dl have adjacent granules, Lim is incomplete on anterior third and have sparse granules, Dl with one posterior spinoid granule; III with 8 complete carinae of which Vsm, Vl, Lsm and Dl have adjacent granules, Dl with one posterior spinoid granule ( Fig. 17 C); IV with 8 complete carinae of which Vsm, Vl, Lsm and Dl have adjacent granules, Dl with one posterior spinoid granule ( Fig. 17 C); V with 5 complete carinae with uniform and sparse granules; intercarinal surface moderately granular. Telson: vesicle with five vestigial carinae of which the ventral is well marked; aculeus long and strongly curved; subaculear tooth strong and spinoid with two small dorsal teeth. Pedipalp: femur with 5 carinae of which Da, Dp, Va and Mp have small and adjacent granules; Ma with bigger granules; patella with 7 carinae of which Ad, Am, Av and Dm present median and adjacent granules; Am with a proximal spinoid granule ( Fig. 17 B); Pd, Pm and Pv with small and continuous granules; chela with 9 carinae, with small and continuous granules; absence of basal lobe on the movable finger of chela ( Fig. 17 B); all surfaces moderately to weakly granular. Movable fingers with 17–16 oblique rows of granules. Trichobothriotaxy: ortobothriotaxy A—α ( Vachon, 1974 and 1975).

Variations. Some specimens of T. stigmurus present the lateral longitudinal dark brown stripes, in some cases reaching the III or IV tergite or restricted to a small spots on posterior region of tergites I–VI.

Distribution. States of Piauí, Ceará, Rio Grande do Norte, Pernambuco (recently recorded in Fernando Noronha by Freitas & Vasconcelos, 2008), Paraíba ( Dias et al, 2006), Alagoas, Sergipe and Bahia, Brazil ( Fig. 18 ).

Figures

FIGURE 1. Tityus aba (♂ IBSP 3394 e Ψ IBSP 3395; Poções, Bahia, Brazil). Male (A) and female (B) in dorsal view.

FIGURE 18. Distribution of T. stigmurus.

FIGURE 16. T. stigmurus. (♂ IBSP 1330, Ψ IBSP 1449; Raso da Catarina, Bahia, Brazil). Female in dorsal (A) and ventral (C) view; Male in dorsal (B) and ventral (D) view.

FIGURE 9. T. martinpaechi (♂ and Ψ IBSP 4502; Chapada de Ibiapaba, Ceará, Brazil). Female (A) and male (B) in dorsal view.

FIGURE 17. T. stigmurus. (♂ IBSP 1330, Ψ IBSP 1449; Raso da Catarina, Bahia, Brazil). Right palp in dorsal view: female (A) and male (B); Metasomal segments and telson in lateral view: male (C) and female (D).