Brachistosternus anandrovestigia, Ojanguren-Affilastro & Pizarro-Araya & Ochoa, 2018

Ojanguren-Affilastro, Andrés A., Pizarro-Araya, Jaime & Ochoa, José A., 2018, Five new scorpion species of genus Brachistosternus (Scorpiones: Bothriuridae) from the deserts of Chile and Peru, with comments about some poorly studied diagnostic characters of the genus, Zootaxa 4531 (2), pp. 151-194 : 183-189

Brachistosternus anandrovestigia n. sp.

( Figs. 1 , 2F , 20–23 ; Table 2 )

Type material. Holotype male: Peru, Tacna Department, Sama Province, Quebrada de Burros , 570 m asl, (18°00'10" S; 70°49'36" W), 21/I/2005, E. Oscco & J. A. Ochoa coll. ( MUBI) . Paratypes: same data as holotype, 1 female ( MUBI) ; same locality and collectors as holotype, 550 m asl, 19/XII/2003, 1 male, 1 juvenile male ( MACN) , 3 males, 2 juveniles females ( MUBI) .

Etymology. The name of this species refers to the lack of metasomal glands or androvestigia on metasomal segment V.

Diagnosis. Brachistosternus anandrovestigia n. sp. is a member of the subgenus Brachistosternus because of the trichobothrial pattern and the shape of the hemispermatophore. It can be separated from most other species of genus Brachistosternus because males lack the paired dorsal glands of metasomal segment V or androvestigia. So far the only known species of this genus that lacks the androvestigia is Brachistosternus sciosciae Ojanguren- Affilastro, 2002; both species can be easily separated because B. sciosciae is almost unpigmented whereas B anandrovestigia bears a densely pigmented carapace and sternites. Also the telson of B sciosciae males is conspicuously flattened, being globose in B. anandrovestigia . The hemispermatophore of B. sciosciae lacks the basal spines that are present and well developed in B. anandrovestigia .

According to the phylogenic analysis of Ceccarelli et al. (2016), B. anandrovestigia ( Brachistosternus sp. 1 in Ceccarelli et al. 2016), is most closely related to B. turpuq , but this species bears well developed androvestigia.

Description. Based on the holotype male (MUBI) and paratypes (MACN, MUBI). Total length, males: 42.38– 54 mm (N=5; mean= 46.08 mm); 44.64 mm in the only studied female. Colour: Base colour dark yellowish, with dark brown pigmentation pattern covering most of the carapace and tergites ( Fig. 20 A–D). Chelicerae densely pigmented in fingers and articulation, the rest unpigmented. Carapace densely pigmented, except for some small unpigmented patches in lateral and posterior margins; ocular tubercle black. Tergites I–VI covered by dense pigment pattern that leaves some unpigmented patches. Tergite VII with reticulate pattern covering most of its surface and fusing into a dark spot along the posterior margin of the segment. Sternites, sternum, genital opercula and pectines unpigmented. Metasomal segments dorsal surface with reticulate pigment pattern medially, well marked in segment I, fainter in the posterior segments; ventral and lateral surfaces unpigmented. Telson: vesicle unpigmented, aculeus dark brown. Pedipalps: trochanter unpigmented; femur with faint stripes along dorsointernal, dorsoexternal and ventroexternal margins, joining in a dark dorsal spot distally. Patella, with faint dorsointernal, external and ventroexternal stripes. Chela unpigmented. Legs: coxae and trochanters unpigmented; femorae with faint pigment pattern in the posterior half; patellae covered with faint pigment pattern; tibiae, basitarsi, and telotarsi unpigmented.

Chelicerae: anterior margin of movable fingers strongly curved; movable fingers with two very small subdistal teeth, with the anterior one absent or fused with the posterior one in many specimens.

Pedipalps: Femur with DI, DE and VI carinae well developed and extending the entire length of segment ( Fig. 21F ), more developed in males than in females; with two DE macrosetae, and one DI macroseta; anterior margin with scattered large sized granules and one macroseta; posterior margin with four to six macrosetae, rest of the intercarinal surfaces smooth. Patella, DI and VI carinae well developed and extending entire length of segment ( Figs. 21G, H ), external surface granular in males, smooth in females; with one DI macroseta and two VI macrosetae. Chela manus slender, slightly more robust in males ( Figs. 21 A–E), length/width ratio, males: 3.58– 3.93 (N=5; mean=3.71); 4.04 in the only female; length/height ratio, males: 2.90–3.09 (N=5; mean=2.99), 2.97 in the only female; with a well developed VM accessory carina, which is blunt in females and slightly granular in males; external surface with reticular granular pattern in males, smooth in females; internal surface with slight bulge near articulation of movable finger (females), or with a pronounced, subtriangular projection (males); fingers medium sized, with a median row of denticles, and six or seven pairs of accessory denticles in both, fixed and movable fingers. Trichobothrial pattern orthobothriotaxic Type C, femur with 3 trichobothria (d, i, e), one macroseta (M1) between with d and i; patella with 19 trichobothria (2 d, i, 3 et, est, 2 em, 2 esb, 5 eb, 3 V), with esb 2 petite; chela with 26 trichobothria (Dt, Db, 5 Et, Est, Esb, 3 Eb, dt, dst, dsb, db, et, est, esb, eb, ib, it, 4 V), with Et 4 petite, Esb forming triangle with Eb 2 and Eb 3.

Carapace: anterior margin almost straight, with a small median projection, and four short macrosetae. Surface: granular, more so in males, except the median dorsal area that is smooth. Anterior longitudinal sulcus, posterior longitudinal sulcus, and lateral sulci present and well developed, less developed in females. Median ocular tubercle well developed, placed in the middle of the carapace, with a well developed interocular sulcus and some anterior granules, median ocelli medium sized, facing laterally, ca three diameters apart; with one seta behind each eye. Lateral ocelli pattern type 3A; with three small lateral ocelli in a prominence on each side of carapace, two placed anteriorly, the anterior one placed slightly above the median one, third ocellus similar in size to the anterior one, and slightly above the others. Middle lateral ocellus slightly smaller.

Legs: Surfaces smooth, except for the external and ventral surfaces of femora and patellae of legs III and IV which are slightly granular, more so in males. Basitarsi each with two pedal spurs, with the internal one, one third the size of the external in legs I and II, and about 30 % smaller than the external in legs III and IV. Telotarsi elongated, and ventrolaterally compressed, dorsally with a row of setae, ventrally each with a ventromedian row of small hyaline setae, and paired rows of ventrosubmedian setae. Counts of setae on telotarsus of leg III: Dorsal setae: 10–11 (N=9; median=11); ventrosubmedian prolateral setae: 7 in all studied specimens; ventrosubmedian retrolateral setae: 5–6 (N=9; median=6). Ungues shallowly curved, slightly asymmetrical in legs I and II, retrolateral one about 25 % smaller; both equal in length in legs III and IV; telotarsus IV more elongated than the rest, and slightly less curved ungues than the rest of the tarsi.

Pectines: medium sized. Tooth count, males: 37–39 (N=5; median=38); females: 27-31 (N=3; median=30.5); internal basal lamella similar in males and females.

Sternum: With two conspicuous subtriangular lateral lobes, each with a microseta and a medium sized macroseta.

Genital opercula: Sclerites subtriangular.

Tergites: I–VI: with two dorsosubmedian setae, surface smooth in the median area, slightly granular in the lateral and posterior margins, more so in males, with the granules occupying the posterior half of the segment; tergite VII: with two dorsosubmedian setae; smooth in the anterior third, densely granular in the posterior two thirds, except for the area below the lateral carinae; with two dorsosubmedian carinae in the posterior third, and two lateral carinae in posterior two thirds of the segment.

Sternites: Sternites III-VI surface smooth in females, densely granular in males; with medium sized spiracles, and paired shallow submedian furrows; sternite VII smooth in females, densely granular in males.

Metasoma: Metasomal segment I, dorsal surface granular, except for the area around the median sulcus that is smooth; DL carinae extending the entire length of the segment; lateral surfaces granular; LM carinae extending the entire length of the segment, LIM carinae in the posterior two thirds of the segment; with one LIM macroseta in the posterior third of the segment; ventrally densely granular in males, smooth in females, with blunt VL carinae, two pairs of VL setae in the median part of the segment (2-2), and two posterior VSM setae. Metasomal segments II and III similar to segment I but less granular; with an additional DL and a LM setae; the LIM carinae is restricted to the posterior third in segment III. Metasomal segment IV, dorsal surface with sparse granulation; DL carinae extending the entire length of the segment, connected with the lateral accessory carinae which is present in the posterior third of the segment; lateral surfaces densely granular; LM carinae extending the entire length of the segment, but represented by scattered granules; LIM carinae represented by some posterior granules and two posterior setae; ventrally with blunt VL and VM carinae, granular in males, smooth in females; with 28 to 38 scattered setae. Metasomal segment V elongated, length/width ratio, males: 1.64–1.85 (N=5; mean=1.77); 1.69 in the only female; dorsal surface smooth medially ( Fig. 22C ), males without androvestigia, but with a shallow depression in its place ( Fig. 22B ); densely granular in the DL margins and forming a conspicuous DL carina; lateral margins granular, more so in males; LM carinae represented by a row of granules and seven to nine setae; ventral surface with sparse medium sized granules, VM carina granular ( Fig. 22E ), straight, extending the entire length of the segment; usually with three transverse rows of macrosetae of two macrosetae each, (distribution 2-2-2); VL carinae granular, straight, and extending the entire length of the segment, with 7 to 8 VL macrosetae (N=9; median=8).

Telson: Vesicle relatively globose, slightly less so in males; length/height ratio, males: 3.13–3.45 (N=5; mean=3.28); 3.29 in the only female; ventral and lateral margins with scattered blunt granules; ventrally with two shallow VSM furrows subtending a VM carina; laterally with a conspicuous furrow on each side; dorsal surface smooth and slightly concave, in males there is a shallow pit. Aculeus longer than the vesicle, shallowly curved, slightly more in males ( Figs. 22A, D ).

Hemispermatophore: Basal portion well developed. Distal lamina well developed, similar in length to the basal portion ( Fig. 23A ); apex curved medially towards the internal margin; distal lobe (distal posterior flexure) well developed, occupying about a third of the distal lamina; distal crest medium sized, occupying the apical third of the distal lamina and without transverse crests, not connected to the posterior margin of the distal lamina. Left hemispermatophore, cylindrical apophysis of the basal lobe well developed, being slightly wider in its median part, with an acute and curved tip ( Fig. 23B ), barely reaching the base of the distal lobe, and slightly longer than the laminar apophysis; laminar apophysis bilobed, with a median internal longitudinal flexure that divides it into two lobes; row of spines and basal spines well developed and in the same line, internal spines well developed; basal triangle well developed, formed by three or four chitinous crests. Right hemispermatophore without a cylindrical apophysis ( Fig. 23C ), ILA well developed, with well developed spines in its base and in its median part, less developed in its anterior third (some specimens with smooth areas in its dorsal margin); the rest as left hemispermatophore.

Distribution. Brachistosternus anandrovestigia n. sp. is known only from de type locality (Quebrada de Burros) in the Tacna Department of Southern Peru, recorded from 550–570 m asl ( Fig. 1 ).

Ecology. This species was collected in a disturbed Lomas biotope in slopes with rocky ground, the area presents a sparse shrub vegetation and columnar cacti. Brachistosternus anandrovestigia n. sp. is sympatric with an undescribed species of the genus Orobothriurus .

Figures

FIGURE 1. Distribution map of Brachistosternus gayi n. sp., Brachistosternus philippii n. sp., Brachistosternus contisuyu n. sp., Brachistosternus misti n. sp. and Brachistosternus anandrovestigia n. sp.

FIGURES 2A–F. Type locality of Brachistosternus species herein described. A. Brachistosternus gayi n. sp.; B. Brachistosternus philippii n. sp.; C. Brachistosternus contisuyu n. sp.; D, E. Brachistosternus misti n. sp.; F. Brachistosternus anandrovestigia n. sp.

FIGURES 20A–D. Brachistosternus anandrovestigia n. sp., habitus. A. Male, dorsal aspect; B. Male, ventral aspect; C. Female, dorsal aspect; D. Female, ventral aspect. Scale bars: 1 cm.

FIGURES 21A–H. Brachistosternus anandrovestigia n. sp. A. Left pedipalp chela, male, internal aspect; B. Left pedipalp chela, male, ventral aspect; C. Left pedipalp chela, male, external aspect; D. Left pedipalp chela, male, dorsal aspect; E. Left pedipalp chela, female, ventral aspect; F. Left pedipalp femur, male, dorsal aspect. G. Left pedipalp patella, male, external aspect; H. Left pedipalp patella, male, ventral aspect. Scale bars: 1mm.

FIGURES 22A–E. Brachistosternus anandrovestigia n. sp. A. Metasomal segment V and telson, male, lateral aspect; B. Metasomal segment V male, dorsolateral aspect; C. Metasomal segment V, male, dorsal aspect; D. Metasomal segment V and telson, female, lateral aspect; E. Metasomal segment V, male, dorsal aspect. Scale bars: 1mm.

FIGURES 23A–C. Brachistosternus anandrovestigia n. sp. A. Left hemispermatophore, external aspect. B. Left hemispermatophore, detail of the lobe region; C. Right hemispermatophore, detail of the lobe region. Scale bars: 1mm.