Paruroctonus gracilior (Hoffmann, 1931)

Uroctonoides gracilior Hoffmann, 1931: 406-408, fig. 42-43; Gertsch 1958: 15, 17.
Vejovis (Paruroctonus) pallidus Williams 1968a: 6-11, fig. 4-6; Díaz Najera, 1975: 7, 20 (synonymized by Haradon, 1985: 22-23).
Hoffmanniellius gracilior: Mello-Leitão, 1934a: 80.
Paruroctonus gracilior: Werner, 1934: 283, fig. 363; Stahnke, 1957: 253; Stahnke, 1961: 206; Bücherl, 1971: 329; Williams, 1972: 3; Soleglad, 1972a: 73; Soleglad, 1973b: 355, tbl. 2; Stahnke, 1974a: 136-138, fig. 10A, 11A-B; Williams, 1980: 31-32, fig. 35A-B, 36C-D; Sissom & Francke, 1981: 97-98, 102, 107, fig. 7-12, 33-35; Francke & Soleglad, 1981: 242, fig. 22; Haradon, 1985: 21-23, 40; Sissom, 1997: 13; Kovarík, 1998: 144; Sissom & Jackman, 1998: 151; Beutelspacher, 2000: 66, 136, 138, 152, map 31; Sissom, 2000:506; Soleglad & Fet, 2003a: 8, 31, 36, 104, fig. 75.
Uroctonoides gracilior: Gertsch, 1958: 15, 17; Vázquez & Zaragoza, 1979: 583.
Vejovis (Paruroctonus) gracilior: Gertsch & Allred, 1965: 9; Gertsch & Soleglad, 1966: 6, 26-30, fig. 13, 18, 21, 23, 33-35, tbl. 3; Williams, 1968a: 7.
Hoffmanniellus (ISS) gracilior: Gertsch & Soleglad, 1966: 26 (in synonymy); Williams, 1972: 3  (in synonymy). Misspelling of Hoffmanniellius Mello-Leitfo, 1934: 80.
Paruroctonus pallidus: Williams, 1972: 3; Soleglad, 1972a: 73; Soleglad, 1973b: 355, tbl.2; Stahnke, 1974a: 138; Sissom & Francke, 1981: 98, 102; Beutelspacher, 2000: 69, 138, 152, map 31.
Uroctonus gracilior: Díaz Najera, 1975: 2 (erratum)
Vaejovis gracilior: Díaz Najera, 1975: 2, 6, 8, 20.

type(S):  
of Uroctonoides gracilior Hoffmann: Lectotype (designated by Gertsch & Soleglad, 1966: 29) male (adult) from México, Aguascalientes, Tepezala (C. C. Hoffmann), tagged #1. Depository: American Museum of Natural History (AMNH).  
of Vejovis (Paruroctonus) pallidus Williams: Holotype male (adult) from México, Coahuila, 0 .5 kilometer SW Cuatro Cienegas (S. C. Williams, et al.). Depository: California Academy of Sciences, Type No. 10174.

Original Description: .

subsequent accounts:
Gertsch and Soleglad 1966

DIAGNOSIS: Very distinct species (fig. 13), readily identified by following combination of characters: Carapace proportionately broader than in other species, produced in front into distinct angle at middle, and having entire interocular area marked with dark pattern to front margin. Tergites of preabdomen having dark pattern except for pale stripe along each side and indistinct median pale line or stripe running length. Chelicerae larger than those of other species of series and distinctive in following features: fixed finger lacking any trace of basal teeth or nodules on weak ventral keel; apical tooth on upper margin of movable finger relatively small and widely separated from enlarged apical tooth of lower margin; teeth on lower margin of movable finger quite variable in size and differing in almost every specimen.
COLORATION: Base color pale yellow to dusky yellowish brown, with dark pattern as follows: Eyes and eye tubercles black. Carapace (fig. 18) with brown or dusky maculation of triangular shape beginning behind median eyes and enclosing most of pars cephalica except for paler front margin and narrow ring around median eyes. Thoracic portion of carapace pale except for dusky streaks mostly near posterior margin. Tergites I-VI of preabdomen (fig. 21) with transverse dusky or brown bands enclosing a series of paler spots on each side; dark bands covering entire segments except for pale stripe along each side margin and indistinct pale median stripe running full length. Tergite VII mostly pale, with dusky shadings. Under side of carapace and sternites of preabdomen dull yellow. Cauda dull yellow to yellowish brown, with faint dusky shadings of ventral keels in some individuals. Legs pale yellow, with dusky shadings on upper surfaces. Chelae yellowish brown, lightly mottled with black, and with keels dusky in some. Sting red.
STRUCTURE: Typical of subgenus and similar in both sexes to that of boreus except as noted below. Male smaller than female. Measurements given in table 3.
Carapace: Shape of carapace of female from Hope, New Mexico, as shown in figure 18. Anterior margin lightly produced at middle to slight rounded projection, occasionally essentially straight, set with six suberect setae; sides essentially straight to broadly rounded at caudal angle; length and breadth subequal, proportionately broader than in other species. Median eyes somewhat enlarged from average, set on low tubercles connate along inner edges; width of median diad about one-fourth of width of carapace at that point (26/96). Carapace of male granulate over most of surface, with many coarse, black granules forming conspicuous rows on dark pattern; granulation of female less developed.
Preabdomen: Tergites dull, quite rough, with many conspicuous granules forming transverse rows in posterior portion of each.
Cauda: Dorsal and superior lateral keels all distinct but not sharply angled, crenulate, set with many small, rounded granules. Inferior median keels essentially obsolete on segments I-III, weak and irregularly crenulate on segment IV. Inferior lateral keels weak and mostly smooth on segments I-IV. Inferior lateral keels of segment V roundly angled, with heavy granules. Segment V much longer than carapace in both sexes. Segments I-IV with 4-5-5-6 pairs of setae on obsolete inferior median keels.
Telson: Vesicle quite slender, about twice as long as slightly curved sting, smooth. Subaculear nodule inconspicuous. Vesicle about as wide as segment V of cauda.
Pectines: Similar to those of boreus in both sexes. Those of females of medium width and length; middle lamellae consisting of about 16 ovoid pieces; pectinal teeth numbering from 18 to 20. Those of male much larger and broader; middle lamellae about 25 small ovoid pieces; pectinal teeth long, curved, 25-29 in number.
Chelicerae: Similar in both sexes (figs. 33-35) and larger than those of other species. Fixed finger a thin blade with long distal tooth, without trace of basal nodules on obsolete ventral keel. Movable finger a long, flat blade, with five strong teeth, on upper margin of which distal tooth is of medium size and quite remote from long apical tooth of lower margin (fig. 34); carina of lower margin dissected in middle or basal portion into four or more quite large teeth of irregular size and shape.
Pedipalps: In both sexes short, with heavy hands and short fingers, with sculpturing essentially like that of boreus. Chelae with all carinae well developed and coarsely granulated. Inner keels of fingers weakly scalloped.
Walking legs: Protarsi with irregular series of six to eight principal bristles.

Haradon 1985

Diagnosis.—See infragroup diagnosis above. Description .—Supplementing above diagnosis, Gertsch and Soleglad (1966: 26), and Sissom and Francke (1981: 97). Basic fuscous pattern (see Gertsch and Soleglad 1966: figs . 18, 21) varies from dark and distinct to obsolete . Cheliceral fixed digit without denticles on inferior carina. Humeral macrosetae: internals include one supramedial, three (occasionally four) inframedials on proximal 3/5; four dorsals; usually three external medials, middle seta often small in immatures and juveniles. Brachial macrosetae: four internals. Chela: palm with eight major carinae moderately to well developed and granular in both sexes, intercarinal surfaces weakly to moderately concave; macrosetae include two or three on internal carina, usually four on ventrointernal carina, usually eight or nine flanking ventral carina, none on fixed fmger, one long internal proximal and sometimes one short internal at mid-length of movable fingers; fingers essentially unscalloped in both sexes; primary denticles in seven rows on movable finger, six on fixed finger; supernumerary denticles well developed, six on fixed finger, seven on movable finger. Basitarsi I-III: not conspicuously compressed laterally; superior setae on I-III irregularly distributed, usually three distal plus two proximal on III; mrs seta on I at most only slightly offset from superior setae, on II moderately offset, on III set well apart from superior setae . Telotarsal setae I-IV: proinferiors 1,2,2,2; two each promedials, prosuperiors, retrosuperiors and retromedials; usually one retroinferior; one retroinferior terminal. Ungues I-IV about 1/3 as long as telotarsus. Pectines extend to proximal margin of femur IV in males, to 1/4 length of trochanter IV in females. Metasomal carinae: ventral and ventrolaterals I-III in males essentially smooth to crenulate (often strongly so), in females smooth to weakly crenulate, IV entirely crenulate in both sexes . Metasomal setae: counts variable; ventrals I-IV primarily 34,5-6,5-6,5-7; ventrolaterals I-V primarily 2-3,4,4-5,4-6,7-15 ; dorsals I-IV 0,1,1,2 (fewer than 5% with 1,1,1,2).
Key - Cheliceral fixed digit inferior carina does not extend proximally to level of bicusp; carapace length/cheliceral fixed digit length ratio 4.1 or less………………….gracilior infragroup, P. gracilior

Sissom and Hendrickson 2005:39 Key to the Vaejovid Scorpion Species of Northeastern México - Dorsolateral carinae of metasoma more or less evenly denticulate throughout (i.e., without an enlarged terminal denticle); legs I–III with distinct retrolateral setal combs; Anterior margin of carapace distinctly convex; fixed cheliceral finger with ventral keel restricted to tip of finger.......Paruroctonus gracilior (= pallidus)
 

distribution: NORTH AMERICA. México (Aguascalientes, Coahuila), USA (southeastern Arizona, southern New México, southwestern Texas). View Map

published records:  Uroctonoides gracilior Paralectotypes: México, Aguascalientes, Tepezala (C. C. Hoffmann), 2 males (AMNH),. Vejovis (Paruroctonus) pallidus Paratypes: 64M, 25F (CAS, including an allotype”CAS Type No. 10174”), same locality as holotype; 5M, 2F (CAS), 4.3 km NNW Cuatro Cienegas; 1F (4 km E Cuatro Cienegas). Other records: Arizona: Cochise County: Portal, July 1 to September 4, 1965 (R. M. Hastinigs, W. J. Gertsch, V. Roth), 27 males, four females. New Mexico: Hidalgo County: Rodeo, August 29, 1964 (R. Hastings), male. Eddy County: Hope, September 23, 1950 (W. J. Gertsch), female. Coahuila: Twenty miles east of Saltillo, July 16, 1965 (W. J. Gertsch, V. Roth), male.

notes:  Haradon 1985 Variation .—Some specimens from arenicolous populations had on basitarsus III, in addition to the usual 3+2 superior setae, a sixth seta (variably developed) between and prolateral to the proximal and distal groups, resulting in a 4+2 pattern ; distinctly smaller extraneous setae might also be present, particularly in arenicolous specimens. The ventrolateral metasomal seta counts varied considerably, including on V; e .g., eight to 15 (80% with nine to 12) in Texas and New México, seven to nine (68% with eight) in southeastern Arizona, and seven to nine, normally eight, in Cuatro Cienegas basin of Coahuila. Adult carapace lengths varied considerably among the samples; e .g ., 4 .1-5.0 mm (Chiricahua Mts ., Arizona), 4 .5-6 .5 mm (Big Bend region, Texas), and 6 .0-7.2 mm (Cuatro Cienegas basin, Coahuila).
Haradon 1985 Remarks.—Paruroctonus pallidus, distinguished from P. gracilior originally (Williams 1968a: 7) by apparent differences in pigmentation and in the metasomal carinae, and further (Sissom and Francke 1981 :98, 102) by apparent differences in metasomal seta counts, is here considered an arenicolous pigmentation variant of P. gracilior. The range in variation in the development of the metasomal carinae and the metasomal seta counts in P. gracilior subsumes that of P. pallidus. When detectable, vestigial traces of fuscosity in P. pallidus specimens conform to the general pattern characteristic of P. gracilior. The amount of fuscosity typical of a population is often correlated with the darkness of the substrate, and in several Paruroctonus species considerable variation in pattern intensity exists (Haradon 1983 :253, 261). The above synonymy is based on the examination of P. pallidus paratypes (CAS, OFF); the lectotype and two cotypes of P. gracilior (AMNH); and approximately 120 other specimens of P. gracilior from previously reported material (Gertsch and Soleglad 1966; Sissom and Francke 1981) from Arizona, New México, Texas and Chihuahua.

[Per Sissom Catalog (web)]  - Beutelspacher (2000) recognized both P. gracilior and P. pallidus in his catalog of Mexican scorpions. Because he failed to cite Haradon's (1985) revision of Paruroctonus, it is clear that he was unaware of the synonymy.