Lauren A. Esposito, Humberto Y. Yamaguti, Cláudio A. Souza, Ricardo Pinto-Da-Rocha & Lorenzo Prendini, 2017, Systematic Revision of the Neotropical Club-Tailed Scorpions, Physoctonus, Rhopalurus, and Troglorhopalurus, Revalidation of Heteroctenus, and Descriptions of Two New Genera and Three New Spec, Bulletin of the American Museum of Natural History 415, pp. 1-134: 94-95
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Physoctonus striatus , sp. nov.
Physoctonus debilis: Porto et al., 2010: 295 , table 1 (part).
TYPE MATERIAL: BRAZIL: Bahía: Xique- Xique, 10°49′60″S 42°43′60″W: Holotype ♂ (MZSP 30869/AMCC [LP 9681]), 2.x.2008, T.J. Porto. Paratype ♂ (MZSP 31128/AMCC [LP 9950]), same data except 3.x.2008, T.J. Porto.
DIAGNOSIS: Physoctonus striatus , sp. nov., differs from its sister species, P. debilis , as follows. The mesosomal tergites of P. striatus are dark, with transverse bands of infuscation, whereas the tergites of P. debilis are uniformly pale, except for the infuscate dorsomedian carinae, which form a thin stripe longitudinally. The carinae of the carapace, pedipalps, and metasoma are less pronounced in P. stria - tus than in P. debilis : for example, the lateral inframedian carinae of metasomal segments II and III are restricted to the posterior third of the segment in P. striatus , but complete in P. debilis ; and the retromedian and secondary accessory carinae of the pedipalp chela manus are vestigial to absent in P. striatus , but complete and granular in P. debilis . Pedipalp chela fixed finger trichobothrium db is aligned with trichobothrium et in P. striatus but situated distal to et in P. debilis .
ETYMOLOGY: The species name refers to the transverse bands of infuscation on the mesosomal tergites.
DESCRIPTION: The following description is based on the holotype male unless otherwise noted (for measurements, see table 3). Only characters that differ from the generic description are noted.
Total length: Small scorpions, 22–26 mm.
Color: Base color dark yellow to light brown. Carapace immaculate except interocular surface infuscate, forming dark triangle, almost reaching anterior margin, and thin, dark line of infuscation around margins. Tergites each with infuscate median carina forming a thin dark line longitudinally, with transverse band of infuscation, and a dark line of infuscation around margins. Coxosternal region, pectines, and sternites immaculate, dark yellow. Metasomal segments I –IV, dorsal surfaces immaculate, similar in color to carapace and tergites; II –IV, ventral surfaces infuscate, forming a longitudinal stripe; V completely infuscate. Telson vesicle similar to metasomal segment V dorsal surface, aculeus almost black. Chelicerae, pedipalps, and legs brown, entirely infuscate.
Carapace: Pentagonal in shape, anterior width approximately two thirds posterior width. Median ocular tubercle low; median sulci shallow; lateral ocular carinae continuous with posterior median carinae. Carinae obsolete, finely granular and barely distinguishable from surface granulation; anterior margin with large round granules.
Pedipalps: Pedipalp femoral and patellar carinae coarsely granular; chelal carinae more finely granular (fig. 48C). Chela fixed finger trichobothrium db aligned with trichobothrium et. Retromedian carina vestigial, restricted to distal quarter of chela manus; secondary accessory carina of chela manus absent.
Legs: Legs III and IV, tibial spurs absent; I –IV, surfaces carinate; basitarsi each with simple prolateral pedal spur; telotarsi each with distinct pro- and retroventral rows of fine, acuminate macrosetae.
Sternum: Subtriangular. Median longitudinal sulcus shallow anteriorly, deep, wide posteriorly.
Genital operculum: Genital opercula suboval, completely divided longitudinally; genital papillae present (♂).
Pectines: Tooth count, 15/15 (♂). Pectinal plate trapezoid, with deep anterior notch (fig. 20B).
Mesosoma: Tergites IV –VI slightly wider than than I –III; I –VI unicarinate, dorsosubmedian carinae absent, dorsomedian carina reduced to posterior half on I –VI. Tergite VII pentacarinate, dorsomedian carina reduced. Sternites III –VI smooth, carinae absent or obsolete; sternite III, lateral margins not forming smooth, raised carina, ventromedian carina not elevated anteriorly, ventrosubmedian surfaces not forming paired depressions, smooth; sternite VII with four granular carinae; respiratory spiracles (stigmata) width more than 5× length.
Metasoma: Metasomal segments I –III each with 10 carinae, IV with eight carinae, V with five carinae; lateral inframedian carinae complete on segment I, restricted to posterior third of segment on II and III, absent on IV and V. Ventral intercarinal surfaces of segments I –IV coarsely granular, dorsal and lateral surfaces weakly granular or smooth, segment V smooth. Metasoma increasing slightly in width posteriorly, segments IV and V wider than I in adult male.
Telson: Vesicle pentacarinate; subaculear tubercle vestigial.
Hemispermatophore: As for genus.
Sexual dimorphism: Females are unknown.
DISTRIBUTION: This species is known only from the type locality in the Brazilian state of Bahía (fig. 9A).
ECOLOGY: The type locality is situated in the Brazilian caatinga, a very dry environment with sandy soil. Specimens were collected under stones during the day or with UV light detection at night. The habitus is consistent with the lapidicolous ecomorphotype ( Prendini, 2001 b).
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