Vaejovis islaserrano, Barrales-Alcala, Diego A., Francke, Oscar F., Devender, Tom R. Van & Contreras-Felix, Gerardo A., 2018

Barrales-Alcala, Diego A., Francke, Oscar F., Devender, Tom R. Van & Contreras-Felix, Gerardo A., 2018, A new Sky Island species of Vaejovis C. L. Koch, 1836 from Sonora, Mexico (Scorpiones, Vaejovidae), ZooKeys 760, pp. 37-53 : 37

Vaejovis islaserrano sp. n. Figs 1, 2, 3, 4, 5, 6, 7, 8, 9

Type material.

Holotype Male, MEXICO: Sonora, Municipio Cananea, vicinity of Observatorio Astrofísico Guillermo Haro, Sierra La Mariquita (31.05444°N, 110.38244°W, 2422 m elev) 03-VIII-2013. Cols: T. R. Van Devender, J. D. Palting, and G. Molina. 1 ♂ (CNAN-T01207).

Paratypes: Same data as the holotype 4 males and 5 females (CNAN-T-01208); 2 males and 2 females (AMNH). MEXICO: Sonora, Cananea, Sierra La Elenita. Near "El 15" (31.00252°N, 110.38944°W, 1911 m) 30-IV-2016. Cols: D. Barrales , J. Cirett, I. Ochoa. Pine-Oak forest.

Etymology.

The specific epithet is regarding the distribution of the species in the highlands of the Sonoran desert and it is composed by the words in Spanish “isla” in reference of island and “sierra” as in mountain range, being the adjective “serrano” and together they compose the name islaserrano , which is used as a noun in apposition.

Diagnosis.

Vaejovis islaserrano sp. n. belongs to the " vorhiesi " group due to the presence of the following characters: the presence of a sclerotized mating plug in the spermatophore; trichobothria ib - it on the base of the fixed finger of the pedipalp chela; the absence of setae on the prolateral and retrolateral sides on the first pair of legs. This is a relatively small scorpion, with adult total length ranging from 18 mm to 24 mm (Table 1). Sternite V with a noticeable whitish oval spot on the posterior fifth, also present on sternite VII. Vesicle of the telson, elongated more than twice longer than wide (L/W: 2.44), and thin, almost as wide as deep (W/D: 1.12). LAS present on both sides of the aculeus. Pedipalp chela fingers dentate margins straight, without scalloping.

Vaejovis islaserrano sp. n. is most similar to Vaejovis bandido Graham, Ayrey & Bryson, 2012, from Sierra Los Ajos, Sonora, but it is easily differentiated by the following characters: the presence of a subaculear spine in V. bandido , whereas in V. islaserrano sp. n. does present a vestigial subaculear spine: the presence of a caudal gland of the telson evident on adult males of V. islaserrano sp. n., whereas in V. bandido it is not evident; the hemispermathophore presents an apical crest on the lamella in V. bandido , whereas V. islaserrano sp. n., presents a lamella without crest. Another species closely related to V. islaserrano sp. n. is V. vorhiesi Stahnke, 1940, from the nearby Huachuca Mountains, Arizona, that can be differentiated as follows: V. vorhiesi presents a subaculear spine, whereas V. islaserrano sp. n. does not present a subaculear spine. Finally, Vaejovis cashi Graham, 2007, from the Chiricahua Mountain in Arizona, differs from V. islaserrano sp. n. in the following characters: smaller size (19 to 22 mm); a small aculear spine present in V. cashi , absent in V. islaserrano sp. n.; the hind laminar hook on the hemispermathophore weakly developed, almost fused with the other hook in V. islaserrano sp. n. versus hooks well differentiated with a deep depression between them in V. cashi .

Description of the holotype male

(Fig. 1a, b). Coloration: Chelicerae, pale yellow coloration, with a black pattern on distal margin of chelae. Carapace, pale yellow coloration, with a diffuse fusco-piceus pattern. Mesososma, tergites pale yellow, with a diffuse fusco-piceus pattern. Sternites III-VII pale yellow, with a diffuse dark pattern on the sides; sternite V with a noticeable pale oval spot on posterior fifth, and sternite VII presents also a noticeable triangular spot on the posterior fourth. Metasoma, segments I-V pale yellow, with a very diffuse black pattern, more evident dorsally on each segment. Telson, pale yellow coloration with a diffuse fusco-piceus pattern present on the ventral face and additionally on the dorsal face, but faint. Pedipalp, Femur, patella and chela pale yellow with a diffuse dark coloration intense at the margins of each segment and on the carinae. Legs, pale yellow, with a diffuse dark coloration present, denser on prolateral face of femur and patella and on prolateral and retrolateral margins of basitarsus.

Prosoma. Chelicerae: Serrula present, well-developed. Dorsal margin of movable finger with the basal denticle smaller than the median followed by two small subdistal denticles and a larger distal denticle; ventral edge of movable finger smooth. Fixed finger with basal denticle bicuspid, subdistal denticle small and distal denticle larger compared to each other. Carapace (Fig. 2a): Anterior margin slightly concave, almost straight; anteromedian longitudinal sulcus shallow; surface of carapace minutely granular on area surrounding the median ocelli, rest of surface granular. Ocular tubercle with superciliary carinae lower than medial ocelli; lateral ocelli type 3A ( Loria and Prendini 2014).

Mesosoma: Tergites I-II, shagreened, with a granular pattern confined to posterior margin; tergites III-VI with anterior half shagreened and posterior half noticeably granular, with median carina present on posterior half of each segment (Fig. 2b). Tergite VII with strongly developed submedian and lateral carinae, paramedian carinae reaching posterior margin; intercarinal surface noticeably granular. Sternites III-VI smooth, slightly granulated on posterolateral margins; sternite VII intercarinal surface shagreened, slightly granular on the sides and with 11 setae; lateral carinae strong, composed by a row of aggregated granules. Pectinal tooth count: 13-14 (Fig. 2b).

Metasoma (Fig. 3 a–c): Dorsal lateral and lateral median carinae on segments I–IV strong, composed by a single line of granules and the distalmost slightly larger than the preceding (Fig. 3a); lateral inframedian carinae on segments I–III strong, composed by a single row of granules and present along the entire segment, on segment IV vestigial, composed by small scattered granules on distal half (Fig. 3b); ventral lateral carinae on segments I–IV strong, composed by a single row of granules; ventral submedian carinae on segment I weak, composed by a row of low granules just above the surface, on segments II–IV, strong, composed by a single row of raised granules. Dorsal and lateral intercarinal surfaces minutely granular, and on ventral face shagreened (Fig. 3c). Segment V: Dorsal lateral carinae strong, composed by a single row of granules on anterior half, wider with scattered granules on posterior half; lateral median carinae strong, composed by an irregular row of granules and present on basal two thirds; ventral lateral carinae strong, composed by a single row of granules; ventral median carina strong, composed by a single row of granules and not reaching posterior margin. Setae count on metasomal segments I–IV as follows: DL: 0/0/1/2; LM: 1/1/0/3; LI: 1/1/0/3; VL: 2/2/0/3; VS: 2/2/0/3. On segment V: DL: 3; LM: 2-3; VL: 3; VM: 3 (Full variation of setal counts in the metasoma, is given in Table 2).

Telson (Fig. 4): Vesicle elongated, more than twice longer than wide (L/W: 2.44), and thin, almost as wide as deep (W/D: 1.12). Subaculear tubercle vestigial to absent (Fig; 4a) Glandular area on the dorsal face present on distal third, and longer than wide (Fig. 4b). Surface of vesicle smooth on ventral and dorsal faces. LAS present on both sides of the aculeus.

Pedipalp (Fig. 5): Orthobothriotaxic type “C”. femur (Fig. 5a) more than three times longer than wide (L/W: 3.5) and slightly wider than deep (W/D: 1.2); dorsal retrolateral and dorsal prolateral carinae strong, composed by an irregular line of granules; prolateral ventrosubmedian carina strong, composed by a line of large granules along the segment; prolateral ventral carina, vestigial, only present by two larger, separate granules; ventral prolateral carina strong, composed by several rows of aggregated granules; ventral median and retrolateral ventral carinae strong, composed by a line of granules; ventral retrosubmedian carina undistinguishable from other granules of the ventral surface; ventral retrolateral carina weak and smooth; retrolateral dorsosubmedian carina strong, composed by an irregular row of larger granules; intercarinal spaces all surfaces are granular. Patella (Fig. 5 b–e): Three times longer than wide (L/W: 3) and wider than deep (W/D: 1.2). Dorsal prolateral and dorsal retrolateral carinae strong, composed by several rows of granules; prolateral subdorsal carina absent; prolateral median carina strong, composed by a line of scattered large granules; ventral prolateral carina strong, composed by a line of granules; ventral median carina strong, composed by a line of scattered granules and present on more than half of segment; ventral retrolateral carina strong, composed by a line of granules; retrolateral median and retrolateral dorsosubmedian carinae weak, almost absent, composed by scattered small granules and a slight costa. Intercarinal spaces shagreened with some scattered granules on ventral face. Chela (Fig. 6 a–d): Manus more than twice longer than wide (L/W: 2.5) and as wide as deep (W/D: 1). Dorsal retrolateral carina weak, with a costa and some small granules; retrosubmedian accessory carina weak, composed by several rows of aggregated small granules; dorsal median carina weak, composed by a costa and some small granules; dorsal prosubmedian and dorsal prolateral carinae strong, composed by several rows of aggregated granules; prolateral dorsal, ventral median, ventral prosubmedian, retrolateral subventral accessory and retrolateral dorsal carinae absent; prolateral median and prolateral ventrosubmedian carinae strong, composed by a row of aggregated large granules; ventral prolateral and prolateral ventral carinae vestigial, almost absent, composed by a slight costa and some scattered granules; ventral retrolateral carina faint, almost absent; retrolateral subventral carina weak, only present as costa; retrolateral median carina faint, only differentiated by a small line of granules and a slight costa. Intercarinal surfaces shagreened. Dentate margins of the pedipalp chela fingers straight; fixed finger with five inner accessory denticles, movable finger with six inner accessory denticles.

Legs: Telotarsi on legs I-IV with a single line of spinules ventrally and with two distal spinules on each leg (Table 3). Prolateral and retrolateral setae on the telotarsi as follows: 0/0:1/1:1/1:1/1.

Hemispermatophore (Fig. 7): Lamelliform (total length: 1.7; Lamella length: 1; width: 0.6mm). Lamella with a weak basal constriction at level of laminar hooks; dorsal trough long; mating plug present, with the distal barb margin smooth.

Variation: The sexual dimorphism in the species is little, but the total length of adult males and females differ by 18.3 to 20.3 mm on males and 20.3 to 24.1 mm on females; the presence of a white patch on mesosomal sternite V and the dorsal face of vesicle present on males and absent in females. The inner denticles, on the pedipalp chela movable finger, vary from five (on three specimens) to six (eight specimens). Carapace longer than pedipalp femur in males (CL/FL: 1.18) than in females (CL/FL: 1.5), but shorter than metasomal segment V (CL/MS V: 0.8) in males, whereas in females it is longer than metasomal segment V (CL/MS V: 1.33). Mesosomal sternite VII, setal counts ranges between eleven and twelve setae. Full variation of measurements is given in Table 1.

Distribution.

This species is known from a few localities in the higher elevations of the Sierra La Mariquita and Sierra La Elenita in Sonora, Mexico at 1911-2422 m. This currently represents the southwestern-most record for the " vorhiesi " group of the genus Vaejovis (Fig. 8).

Natural history

(Fig. 9). The specimens of V. islaserrano sp. n., were collected in August 2013 and September 2016. This species inhabits rocky slopes in pine-oak forest. (Fig. 9b). It was observed active on a cold rainy night, foraging in pine needle litter and living sympatric with Paravaejovis spinigerus (Wood, 1863), which inhabits open, rocky outcrops in the same areas.