Tityobuthus pallidus, Lourenço, 2004

Lourenço, Wilson R., 2004, Further considerations regarding Tityobuthus baroni (Pocock, 1890) with the description of a new species from Ste Marie Island, Madagascar (Scorpiones, Buthidae), Zoosystema 26 (3), pp. 385-392 : 388-391

Tityobuthus pallidus n. sp.

( Figs 2 ; 3A ; 4 ; Table 1)

TYPE MATERIAL. — Holotype: Madagascar, Ste Marie Island , Anbohidena Forest Station, 16°51’S, 49°57’E, 27.XII.1955, IRSM leg., (Muséum national d’Histoire naturelle, Paris RS-8600).

ETYMOLOGY. — The specific name makes reference to the pale color of the new species.

DIAGNOSIS. — Moderate to large in size (with respect to the genus) reaching 31 mm in length. General coloration pale yellow throughout both the body and the appendages. Carapace with a moderately pronounced concavity, forming a weak angle. Cheliceral dentition with basal teeth of movable fingers reduced and fused. Pectines with 14-14 teeth; fulcra present. Sternites smooth; sternite V without any bright zone on posterior edge. Telson less elongated than in the other species of the genus, more globular and rounded; aculeus and curved; subaculear tooth moderate and more to rhomboid with two basal granules. Tibial spurs very reduced. Pedipalp fixed and movable fingers with 8/8 almost linear rows of granules. Trichobothrial pattern type A-α orthobothriotaxic.

DESCRIPTION BASED ON FEMALE HOLOTYPE Coloration

Ground color pale yellow throughout the body and appendages; eyes surrounded by black pigment. Cheliceral fingers reddish-yellow.

Lourenço W. R.

Morphology

Carapace weakly granular; anterior margin with a moderately pronounced median concavity, forming a weak angle. All carinae weak; furrows moderate to weak. Median ocular tubercle distinctly anterior to the centre of the carapace; median eyes separated by less than one ocular diameter. Three pairs of lateral eyes. Sternum subtriangular to subpentagonal. Mesosoma: tergites weakly granular. Median carina weak on all tergites; other carinae absent. Tergite VII pentacarinate. Venter: genital operculum divided longitudinally, each half being oval-shaped. Pectines: pectinal tooth count 14-14; basal middle lamellae not dilated; fulcra present. Sternites smooth with small, elongate stigmata; VII without carinae. Sternite V without any smooth or bright zone on posterior edge. Metasoma: segments I-III with 10 carinae, moderately crenulate. Segment IV with eight carinae, moderately crenulate. Inter- carinal spaces weakly to moderately granular. Segment V with five carinae, rounded and weakly granular except on the ventral surface which shows thin granulation. Telson smooth, with a globular shape and a long strongly curved aculeus; subaculear tooth moderate and tending to rhomboid in shape with two basal granules. Cheliceral dentition characteristic of the family Buthidae (see Vachon 1963); basal teeth of movable fingers reduced and fused; ventral surfaces of finger and manus with setae. Pedipalps: femur pentacarinate; patella and chela with some carinae, weakly crenulate; internal face of patella with five spinoid granules; all faces weakly granular; fixed and movable fingers with 8/8 almost linear rows of granules. Trichobothriotaxy; orthobothriotaxy A-α (cf. Vachon 1974, 1975). Legs: tarsus with numerous fine median setae ventrally. Pedal spurs moderate and tibial spurs very reduced.

RELATIONSHIPS

From its general morphology, and especially in the total lack of pigmentation, Tityobuthus pallidus n. sp. appears to be most closely related to T. guillaumeti Lourenço, 1995 and T. judsoni Lourenço, 1996 . The new species can be readily distinguished from the other two by the following features: 1) the presence of fulcra on the pectines of T. pallidus n. sp., whereas in T. guillaumeti fulcra are absent; 2) a more globular shape of the vesicle in T. pallidus n. sp. (in both T. guillaumeti [ Fig. 3B ] and T. judsoni the vesicle is elongated); 3) pectines of T. pallidus n. sp. have 14-14 teeth whereas those of T. judsoni have 18-19 teeth; and 4) tibial spurs are very reduced in T. pallidus n. sp. but strongly marked in T. judsoni .

of Tityobuthus pallidus n. sp.

Total length 31.1

Carapace length 3.5 anterior width 2.4 posterior width 3.8

Metasomal segment I length 2.3 width 1.8

Metasomal segment V length 5.1 width 1.6 depth 1.7

Vesicle width 1.4 depth 1.4

Pedipalp femur length 3.6 femur width 1.0 patella length 4.6 patella width 1.5 chela length 6.6 chela width 1.2 chela depth 1.1

Movable finger length 4.6

Figures

FIG. 2. — Tityobuthus pallidus n. sp., holotype, trichobothrial pattern; A, tibia, dorso-external aspect; B, patella, dorsal aspect; C, femur, dorsal aspect. Scale bar: 1 mm.

FIG. 3. — Metasomal segment V and telson, lateral aspect; A, Tityobuthus pallidus n. sp., holotype; B, T. guillaumeti Lourenço, 1985,; C, T. baroni (Pocock, 1890),; D, T. lucileae Lourenço, 1996,. Scale bars: 1 mm.

FIG. 4. — Maps of Madagascar and Ste Marie Island, showing the known distribution of Tityobuthus baroni (Pocock, 1890) (1), T. lucileae Lourenço, 1996 (2), T. guillaumeti Lourenço, 1985 (3) and T. pallidus n. sp. (4).