Vaejovis halli Ayrey 2012, sp. nov.

Vaejovis halli Ayrey, sp. nov.

Figures 1–11, 13–15; Tables 1–2

Diagnosis. Small (21.5mm) scorpions. Color is brown, lighter on the legs, with underlying mottling on carapace and mesosoma. (see Figure 1). Pedipalp movable finger with six ID denticles and five on the fixed finger. Carapace of female is slightly shorter than the fifth metasomal segment. Pectinal tooth count for females 11.94 [n=16], males13.81 [n=16]. Ratio of female pectinal tooth count to total length 0.53. Small, spinoid subaculear tubercle. Characters in which V. halli differs from the other sky island Vaejovis are outlined below.

Type material. Holotype female, Mount Ord, Gila County, Arizona, USA, 11 September 2010 (R. F. Ayrey leg.), specimen #343, deposited in USNM. Two paratype males, Mount Ord, Gila County, Arizona, USA, 11 September 2010 (R.F. Ayrey leg.), specimen numbers 340 and 267 (RFA); two paratype females, Mount Ord, Gila County, Arizona, USA, 2 May 2011 (R.F. Ayrey leg.), specimen numbers 393 and 398 (RFA).

Etymology. This species was named in honor of James Hall for his help in finding the scorpions.

Distribution. Known only from the type locality, Mount Ord, Gila County, Arizona, USA.

Description. Based on holotype female, see Figure 2 for dorsal and ventral views.

Color. Color is brown, lighter on the legs. Underlying dark brown mottling found on the carapace and mesosoma, faint on the legs and pedipalps.

Carapace (Fig. 4). Anterior margin of carapace moderately emarginated, posterior margin straight. Carapace moderately granular. Three lateral eyes on each side. Median furrow moderate and traverses entire length of carapace. Ratio of median eyes location from anterior edge/carapace length 0.32; carapace length/width at median eyes 1.31. Carapace is only slightly shorter than metasomal segment V.

Mesosoma. Tergites moderately granular with vestigial median carina on Tergites I–VI. Tergite VII with weak median carina on anterior third and strong dorsal lateral and lateral supramedian granular carinae. Sternites III– VI finely granular and without carinae. Sternite VII with granular ventral lateral carinae on middle third. Presternites smooth. Spiracles ovoid with median side rotated 35 degrees from posterior sternite margin. Sternites with variable number of microsetae.

Sternum (Figs. 6, 7). Sternum is type 2.

Genital Operculum (Figs. 6, 7). Sclerites separated on posterior one-fifth.

Pectines (Figs. 6, 7). Pectinal tooth counts 11–13 (11.94) (±0.66) [n=16] for females and 13–15 (13.81) (±0.57) [n=16] for males. All pectinal teeth have exterodistal angling with large sensorial areas. Middle lamellae 7/7. Fulcra are present. Each fulcra with one to three central setae.

Metasoma (Figs. 8, 9). Carapace of female is only slightly shorter than the fifth metasomal segment. Ratio of segment I length/width 0.77; of segment II length/ width 0.87; of segment III length/width 1.05; of segment IV length/width 1.50; of segment V length/width 2.11. Segments I–IV: dorsolateral carinae strong and granular with distal denticle of I–IV enlarged and spinoid. Lateral supramedian carinae I–IV strong and granular with enlarged spinoid distal denticle. Lateral inframedian carinae moderately granular on segment I, posterior 4/5 of II, 4/5 of III, and weak on 2/5 of IV. Ventrolateral carinae I weak and granular; on II–III moderate, granular; on IV strong, granular. Ventral submedian carinae weak on segment I, weak to moderate on II, moderate, granular on III and IV. Dorsal and lateral intercarinal spaces very finely granular. Segment I–IV ventral submedian setae 3/3. Segment V: Dorsolateral carinae moderate, distally crenulate, basally granular. Lateromedian carinae weak and granular on basal 3/5, obsolete on distal 2/5. Ventrolateral and ventromedian carinae strong. Intercarinal spaces finely granular. Segment V ventrolateral setae 4/4.

Telson (Figs. 5, 8, 9). Smooth with four pairs of large setae on the ventral surface, three large setae along both lateral edges of the vesicle and numerous smaller setae. Small, spinoid subaculear tubercle present.

Chelicerae. Dorsal edge of movable cheliceral finger with two subdistal (sd) denticles. Ventral edge is smooth, with well developed serrula on distal half.

Pedipalp (Fig. 10). Trichobothrial pattern: orthobothriotaxic type C (see Figure 10). Trichobothria ib and it at base of fixed finger. Pedipalp ratios: chela length/width 4.55; femur length/width 3.33; patella length/width 3.63; fixed finger length/carapace length 0.73. Chela. Carinae moderate. Fixed finger median denticles (MD) aligned and divided into six subrows by five outer (OD) denticles and usually five ID denticles. Movable finger with six subrows, five OD denticles and six ID denticles. Femur. Carinae moderate. Patella. Carinae strong, internal surface with very large granules on the DPSc carina.

Hemispermatophore (Fig. 11, paratype male). Both left and right hemispermatophores were extracted from a paratype male and both had a sclerotized mating plug. The right hemispermatophore is 3.45 mm in length and its lamina 1.94 mm. The hemispermatophore is lightly sclerotized particularly in the trough area. On the dorsal surface a subtle distal crest is present on the inner distal aspect of the lamella. The lamellar hook, which is highly sclerotized and widely bifurcated, is quite short, emanating entirely from the dorsal trough. The shortness of the lamellar hook is also indicated by comparing its length to the lamellar length, a ratio value of 0.274. A medium truncal flexure is visible on the external aspect of the trunk/lamina juncture. A very small slightly sclerotized mating plug was located on the ventrointernal surface, just below the ventral trough, embedded in the soft material of the trunk. Its stock is somewhat thick and the barb’s ventral edge is smooth. Its base is wide and irregularly shaped (partially visible in Fig. 11).

Legs. Ventral surface of tarsomere II with single median row of spinules terminating distally with one spinule pair.

Variability. Variability of fixed finger ID denticle count was noted in V. halli as well as several other species of Vaejovis. For V. halli the counts were 6 (n=2) and 5 (n=18), for V. vorhiesi 6 (n=2) and 5 (n=10), for V. cashi 6 (n=2) and 5 (n=10), for V. feti 6 (n=4) and 5 (n=8), for V. deboerae 6 (n=6) and 5 (n=6).

Reproduction. Several females were kept alive in the laboratory in order to observe them giving birth and to count the number of first instar juveniles (see Figure 13). All four females gave birth in the first week of August, 2011. The juvenile count was 20.50 (n=4). The first instar orientation on the mother’s back was non-random, as is seen with many other species of Vaejovis (Hjelle, 1974). They were facing anteriorly with the prosoma down and the metasoma raised over the prosoma of the juvenile immediately posterior to them.

Type Locality Description. The type specimens were found, using a blacklight at night, on Mount Ord, Gila County, Arizona (33°55.606’N, 111°24.343’W) at an elevation of 1780 m asl. The vegetation type is mesic Ponderosa pine and mixed evergreen oak woodland (see Fig. 14). No other scorpions were found sympatrically with V. halli during seven field trips to Mt. Ord.

Comparison of Species

Map in Fig. 15 shows the type localities of the eleven currently described species of Vaejovis from Arizona and western New Mexico. Comparisons of V. halli to each of these species are provided below. Much of the morphometric comparisons discussed below are also shown in Table 2.

Vaejovis jonesi: V. lapidicola, V. paysonensis, V. crumpi and V. bigelowi: These species all usually exhibit seven inner denticles (ID) on the chela movable finger, commonly found in genus Vaejovis, not the reduced number six which is found on the “sky island” species of southern Arizona and V. halli.

Vaejovis tenuipalpus: This species has 6 ID denticles on both the fixed and movable fingers while V. halli has 5 ID denticles on the fixed finger. Female FF L/ Carapace L 0.81–0.89 (Sissom et al., 2012) versus 0.67–0.77 for V. halli and female Chela L/W 5.00–5.39 (Sissom et al., 2012) versus 4.33–4.79.

Vaejovis vorhiesi: In V. halli, the depth of the chela dominates in the ratio calculations, when compared to V. vorhiesi. MVD ranges 18% to 21.3 % and separation is present, this is the only case, of the species examined, that the chela is not thinner in V. halli (see Table 2.). Carapace of female V. halli is slightly shorter than metasomal segment V, while in V. vorhiesi it is often longer than segment V. Female pectinal tooth counts for V. halli are 11.94 [n=16] versus 12.87 (n=339) (Hughes, 2011), male counts 13.81 [n=16] versus 14.99(n=104) (Hughes, 2011) for V. vorhiesi. V. halli is also widely allopatric with V. vorhiesi.

Vaejovis cashi: The first three metasomal segments in V. halli are thinner than in V. cashi, especially in the male: 17.1 to 22.3 MVD, male; 7.8 to 15.5 MVD, female. The chelal palm is also thinner, showing a 1 2.5% to 34.4 % MVD difference, there is significant ratio overlap in the female (see Table 2.) V. halli can be separated from V. cashi by having a single, relatively small subaculear tubercle versus the frequent multiple subaculear tubercles of the latter (Hughes, 2011). Female pectinal tooth counts for V. halli sp. nov. are 11.94 [n=16] versus 10.98 (n=337) (Hughes, 2011), male counts 13.81 [n=16] versus 13.07(n=319)(Hughes, 2011) for V. cashi. V. halli is also widely allopatric with V. cashi.

Vaejovis feti: Thinner chela in V. halli than in V. feti, shown by both the palm width and depth, MVD ranges from 18.5% to 53 %, and standard error separation exhibited in two of the three ratios (see Table 2.). Female pectinal tooth counts for V. halli sp. nov. are 11.94 [n=16] versus 10.00 [n=6], male counts 13.81 [n=16] versus 11.00 [n=6] for V.feti. V. halli is also widely allopatric with V. feti.

Vaejovis deboerae: V. halli can be separated from V. deboerae by size with female V. deboerae 41% larger than female V. halli and female V. deboerae carapace length being 36% longer. A similar but less dramatic size difference is seen in the males. V. halli can also be separated from V. deboerae by the lack of a “whitish patch” on the male sternite V (see Fig. 7); the relatively small subaculear tubercle versus the well developed subaculear tubercle of the latter. V. halli is also widely allopatric with V. deboerae.

Vaejovis electrum: As in other cases above, the chela of V. halli is thinner than in V. electrum when the palm width is compared to the fixed finger length and the palm length. We see 14.8% to 28.5 % MVD, with three out of four showing separation of the standard error range (see Table 2.). V. halli can be separated from V. electrum by having a relatively small subaculear tubercle versus the well developed and frequently multiple subaculear tubercle of the latter (Hughes, 2011). Female pectinal tooth counts for V. halli sp. nov. are 11.94 [16] versus 11.75 (96) (Hughes, 2011), male counts 13.81 [16] versus 13.11(36) (Hughes, 2011) for V. electrum. V. halli is also widely allopatric with V. electrum.