Mastigoproctus ayalai, Viquez, Carlos & De, Luis F., 2007

Viquez, Carlos & De, Luis F., 2007, A new species of Mastigoproctus Pocock, 1894 (Thelyphonida: Thelyphonidae) from Venezuela, Zootaxa 1463, pp. 39-45 : 40-42

Mastigoproctus ayalai sp. n.

( Figs. 1 A–F, 2 A–F, 3 A–B, 4, Table 1 )

Type. Male holotype ( MIZA), Quebrada Trapichote (400 m), La Mina, Pijiguaos (6º 34’ N – 66º 45’ W), estado Bolívar, Venezuela, June 1992, J. M. Ayala. Paratypes: One adult male (IES) and one immature female ( INBio), 8 females, 6 males ( CMGS), 1 female, 1 male ( CJMA), same data as holotype. One female ( INBio), Los Pijiguaos (6º 34’ N – 66º 45’ W), estado Bolívar, Venezuela, June 1991, M. Ayala L.

Distribution. Bolivar state, Venezuela ( Fig. 4).

Etymology. This species is named in honor of J. M. Ayala L., collector of the type series.

Diagnosis. Total length 40–50 mm; dark brown. Male: sternite II (genital plate) with a pair of anterolateral depressions; sternite III with a central, sub-triangular field, covered with short, strong bristles; III–IV undivided. Pedipalps: trochanter moderately granulose, the remainder smooth; tibia higher than wide, not forming a conspicuous angle with respect to its longitudinal axis; scarce reddish hairs on the fingers; small ommatoids, ovoid in shape. Female: seminal receptacle tubular, J-shaped and distally swollen, with basal duct forming an angle of 45º with respect to the longitudinal axis of the opisthosoma. This species may be separated from M. formidabilis Hirst ( Fig. 5 ), by having more attenuate male pedipalp, with tibia ventrally unarmed (in M. formidabilis the tibia has a large ventral tooth); also, female seminal receptacles are very short in M. formidabilis , resembling those of Valeriophonus nara (Valerio) from Costa Rica. The Colombian Mastigoproctus colombianus Mello-Leitão has shorter and digitiform seminal receptacles, as well as stouter, armed and densely punctate pedipalp ( Fig. 5 ).

Male holotype. Reddish brown in color, paler on leg I. Carapace with interocular triangle mostly rugose; the remaining part of the carapace is densely granulose; median eyes separated by 1.4 times one ocular diameter, and 1.0 mm from the anterior margin; posterior fovea is wide and moderately deep; epistoma present. Carapace 1.7 times longer than wide.

Tergites with abundant fine granules; II–III divided by a median longitudinal suture. Segment X laterally divided; XII with one pair of small ovoid ommatoids.

Sternite II (genital plate) with one pair of anterolateral depressions, posterior margin of the sternal plate slightly convex; III two times longer than IV, with a central sub-triangular field, rather elevated and covered with abundant short rigid bristles; II–IV with feeble rugosity. Genitalia broad, twice as wide as long ( Fig. 3 ).

Pedipalps elongate, slightly pilose. Coxa externally granulose, ventrally smooth, with scarce and fine punctuation; apophysis with one distal tooth. Trochanter moderately granulose, with two ventral teeth and five acute dorsal internal ones. Femur sub-cylindrical, smooth, 1.5 times longer than patella, with one small dorsal internal tooth and one strong ventral internal tooth. Patella sub-cylindrical, smooth, apophysis long, without denticles. Tibia (manus) very long, sub-cylindrical and smooth, 1.2 times higher than wide, without internal ventrodistal tooth; movable finger 0.5 times longer than femur.

Legs. Tarsal segments of first leg unmodified. Coxa, trochanter and femur of II–IV externally granulose. Tibiae of III–IV with one ventral distal spur. Basitarsus of II–IV with two ventral distal spurs.

Female. The female differs from the male by having shorter and more robust pedipalps, tibia unmodified, tibial apophysis serrate and shorter; both patella and tibia with one ventral distal tooth. Sternite II (genital plate) smooth, without lateral depressions, with the posterior margin medially and weakly bilobulate; III slight longer than IV, without pilose field; IV with the anterior margin straight. Seminal receptacle tubular, J-shaped, distally swollen and backward directed ( Fig. 3 ).

Natural history. Most of the adult specimens were found under fallen logs, in tropical rain forest. Some of the vinegarroons also came from crevices on walls along the sides of semidry creeks, where they constructed small tunnels each ending in a more wide excavation (J. M. Ayala, personal communication).

Comments. According with recent changes in the taxonomy of Central American whip scorpions ( Viquez and Armas, 2005, 2006; Viquez & Armas in press), the genus Mastigoproctus is now restricted to southern U.S.A., Mexico, Greater Antilles ( Cuba, and Hispaniola), and South America. It is now apparent for us that South American whip scorpions ascribe to this genus are an heterogeneous assemblage of species and for that reason they are needed of a profound revision in order of clarifying its taxonomic status and relationships.

Figures

FIGURE 1. Mastigoproctus ayalai sp. n. Male holotype. A, carapace; B, opisthosoma, dorsal aspect; C – D, pedipalp: C, dorsal aspect; D, ventral aspect; E, sternites II – IV; F, pigidium, lateral aspect.

FIGURE 3. Mastigoproctus ayalai sp. n. Genitalia. A, male, ventral aspect, B, female, dorsal aspect (arrow shows the seminal receptacle).

FIGURE 5. Mastigoproctus formidabilis. Male and female sintype. A – B, male pedipalp; A, female genitalia, dorsal aspect (arrow shows the seminal receptacle); B, Mastigoproctus colombianus. C – D, male pedipalp; C, female genitalia, dorsal aspect (arrow shows the seminal receptacle); D.