Orobothriurus tamarugal, Ochoa & Ojanguren Affilastro & Mattoni & Prendini, 2011

Ochoa, José A., Ojanguren Affilastro, Andres A., Mattoni, Camilo I. & Prendini, Lorenzo, 2011, Systematic Revision Of The Andean Scorpion Genus Orobothriurus Maury, 1976 (Bothriuridae), With Discussion Of The Altitude Record For Scorpions, Bulletin of the American Museum of Natural History 2011 (359), pp. 1-90 : 77-80

publication ID	https://doi.org/ 10.1206/359.1
publication LSID	lsid:zoobank.org:pub:870DFDFC-45BF-49CF-8C3F-2527DB611CFC
DOI	https://doi.org/10.5281/zenodo.4618610
persistent identifier	https://treatment.plazi.org/id/CCECE60F-C1EE-4C82-9302-582A9D28B3B5
taxon LSID	lsid:zoobank.org:act:CCECE60F-C1EE-4C82-9302-582A9D28B3B5
treatment provided by	Felipe
scientific name	Orobothriurus tamarugal
status	sp. nov.

Treatment

Orobothriurus tamarugal View in CoL , n. sp. Figures 15D View Fig , 19F View Fig , 20E View Fig , 21H View Fig , 24F View Fig , 47C, D View Fig , 48–51 View Fig View Fig View Fig View Fig , 53 View Fig ; table 3

TYPE MATERIAL: CHILE: Region I

(Tarapaca´): Iquique Province: Holotype ♂

(MACN-Ar), La Tirana, 2 km W, 20 ° 19959.80 S 69 ° 40907.60W, 999 m, 18.i.2005, A. Ojanguren Affilastro, C. Mattoni and J.A. Ochoa, UV sampling in Prosopis tamarugo forest. Paratypes: Pampa del Tamarugal National Park, Salar de Pintados (salt lake), near rangers’ office and campsite, 20 ° 26916.10 S 69 ° 45955.20W, 1014 m, 18.i.2005, A. Ojanguren Affilastro, C. Mattoni, and J.A. Ochoa, UV sampling in Prosopis tamarugo forest and under salt plates, 1 ♂ ( AMNH), 1 ♀ ( MZUC), 1 juv. ( LBRE).

ADDITIONAL MATERIAL: CHILE: Region I (Tarapaca´): Iquique Province: Pampa del Tamarugal National Park, Salar de Pintados (salt lake), near rangers’ office and campsite, 20 ° 26916.10 S 69 ° 45955.20W, 1014 m, 18.i.2005, A. Ojanguren Affilastro, C. Mattoni, and J.A. Ochoa, UV sampling on Prosopis tamarugo forest and under salt plates, 1 ♀, 4 juv. ( AMNH [LP 4308]).

ETYMOLOGY: The specific name is a noun in apposition referring to the Pampa del Tamarugal, where this species was collected.

DIAGNOSIS: Orobothriurus tamarugal is most closely related to O. curvidigitus , O. paessleri , and O. quewerukana (fig. 5). The carapace possesses a median projection (epistome) at the anterior margin, and a marked anteromedian longitudinal sulcus (figs. 14C, 15C, D), and the males exhibit a curved movable finger on the pedipalp chela (fig. 51A) and a more elongated femur and patella than the females, in all four species. These species may be separated by the shape of the lamina of the hemispermatophore. The frontal crest is more developed and elongated, and the pedicel of the apex narrower in O. curvidigitus and O. quewerukana (figs. 28B, 40E) than in O. paessleri and O. tamarugal (figs. 28C, D, 47D). Most specimens of O. quewerukana possess one or two small folds in the distal crest (fig. 40E), which are absent in O. curvidigitus , O. paessleri , and O. tamarugal (figs. 28A, B, 47D). Additionally, the ventral border of the distal portion of the apex is straight in O. tamarugal , but slightly curved in O. quewerukana . The metasomal carinae of O. curvidigitus , O. quewerukana , and O. tamarugal are similarly developed: the DL and ML carinae are complete and granular on segments I–IV, the VL carinae obsolete and smooth on I–IV, and the VSM carinae almost completely fused with the VL carinae on V. Orobothriurus tamarugal can be separated from O. curvidigitus , O. paessleri , and O. quewerukana by the near complete absence of pigmentation, which is present on the carapace, tergites, and ventral surfaces of the metasoma in the other species. The carinae of the pedipalp femur are less developed in O. tamarugal : the DE carinae, in particular, are incomplete in O. tamarugal (fig. 49A), but complete and comprising larger granules in O. curvidigitus and O. quewerukana (fig. 42A). The IM carina of the male pedipalp chela is present and finely granular in O. tamarugal , but absent in O. curvidigitus and O. quewerukana . The ventral surfaces of sternite VII and metasomal segment I are densely granular in O. tamarugal (fig. 19F), finely granular to smooth in O. quewerukana (fig. 19C), and entirely smooth in O. curvidigitus (fig. 19A).

DESCRIPTION: Based on holotype ♂ and paratypes. Measurements of holotype ♂ and paratype ♀ recorded in table 3.

Total length: ♂, 23.5–35.3 mm (n 5 2); ♀, 30.1 mm (n 5 1).

Color: General color yellowish, with faint dark brown spots. Carapace almost unpigmented (adults), except for median ocular tubercle and lateral ocelli (fig. 48) or faintly pigmented (juveniles), one spot near anterior margin, two spots median laterally and two faint spots posterolaterally, with median ocular tubercle, lateral ocelli, anteriomedian and posteriomedian longitudinal sulci more densely pigmented. Tergites almost unpigmented, except for two large faint spots laterally, delimiting broad, unpigmented median band (fig. 48). Chelicerae, pedipalps, legs, sternum, genital operculum, pectines, sternites, metasoma, and telson unpigmented; aculeus sclerotized, dark reddish brown.

Chelicerae: Movable finger with two subdistal teeth, very small in ♂.

Carapace: Anterior margin granular (♂) or smooth (♀); anteromedian surfaces smooth; lateral margins finely granular, more so in ♂. Anterior margin linear (♀, juv.) or with small median projection (epistome) (♂, fig. 15D). Anteromedian longitudinal, median ocular, and posteromedian sulci well developed; posterolateral sulci obsolete. Median ocular tubercle raised, situated anteromedially; median ocelli two ocular diameters apart.

Pedipalps: Femur, more elongated in ♂, length/width ratio: ♂, 4.05–4.27 (n 5 2), ♀, 3.13; DI and VI carinae complete, granular; DE carina almost complete, coarsely granular in proximal three-quarters, smooth elsewhere; internal surface sparsely and coarsely granular (fig. 49A). Patella, more elongated in ♂, length/width ratio: ♂, 3.45–4.10 (n 5 2), ♀, 2.95; DI and VI carinae almost complete, granular (fig. 49B–D); DE and VE carinae vestigial, finely and sparsely granular in ♂; internal surface sparsely granular, with prominent granule adjacent to trichobothrium i near DI carina. Chela manus slightly rounded, fingers relatively elongated (figs. 49, 50); length/width ratio: ♂, 3.18–4.07 (n 5 2), ♀, 3.83; length/height ratio: ♂, 2.90–3.62 (n 5 2), ♀, 3.83; carinae obsolete, finely granular (less so in ♀) or absent; VM carina restricted to proximal three-quarters of manus; DS, DMA, DI carinae complete, finely and densely granular (♂) or smooth (♀); D carina finely and sparsely granular; IM carina finely and sparsely granular in proximal half (fig. 51B); intercarinal surfaces finely granular (♂, fig. 51) or smooth (♀, fig. 50); internal surface with acuminate apophysis (♂) or low bulge (♀) near articulation of movable finger (♀) (figs. 50A, 51B); movable finger (♂), strongly curved, creating small gap with fixed finger when fingers closed (fig. 51A); fingers, dentate margins each with median denticle row and 5–6 pairs of internal and external accessory denticles.

Trichobothria: Femur with 3 trichobothria, patella with 19, chela with 27 (figs. 49–51). Chela trichobothrium Et 3 situated in same axis as, or slightly basal to Est (figs. 50, 51).

Tergites: Tergites I–VI, surfaces finely granular, more coarsely and densely so near distal margins of III–VI (♂) or smooth (♀). Tergite VII tetracarinate, paired DL carinae restricted to posterior two-thirds of segment, paired DSM carinae to posterior third; intercarinal surfaces granular.

Legs: Femur and patella, prolateral surfaces finely granular, retrolateral surfaces smooth. Femur, ventral carinae weakly developed; other carinae absent. Patella acarinate. Telotarsi, pro- and retroventral rows of spiniform macrosetae with following counts on leg I, 1/1; II, 2/2; III and IV, 3/3.

Pectines: Pectinal tooth count: ♂, 19–21 (n 5 6; mode 5 20); ♀, 17–18 (n 5 2).

Sternites: Sternites III–VI, surfaces smooth; spiracles small, elliptical, and narrow. Sternite VII, surface smooth in anterior half, sparsely granular in posterior half; VL carinae obsolete, slightly more developed in holotype ♂ (fig. 19F); VSM carinae absent.

Metasoma: Segment I, DL carinae complete, moderately to coarsely granular; ML carinae well developed, becoming more coarsely granular in posterior two-thirds; LIM carinae moderately to coarsely granular, restricted to posterior two-thirds, oriented obliquely to antero-dorsal surface, almost joining ML carinae; one pair of macrosetae situated medially between ML and LIM carinae; VL carinae complete, obsolete, finely granular; VSM carinae weakly developed, sparsely granular; two pairs of VSM and VL macrosetae (fig. 19F). Segments II–IV, DL carinae complete, coarsely granular; one pair of DL macrosetae; ML carinae complete, coarsely granular; one pair of ML macrosetae; surfaces between ML and LIM carinae granular on segments II and III; LIM carinae reduced to few granules in posterior third of segment II, less developed on III, absent on IV; VL carinae vestigial, becoming absent toward segment IV; VSM absent or reduced to few scattered granules on segment II (♀); three pairs of VL and VSM macrosetae. Segment V, length/width ratio, ♂, 1.95–2.24, ♀, 1.86; DL carinae reduced to few granules in anterior half; one pair of DL macrosetae; ML carinae obsolete, granular; two pairs of ML macrosetae; lateral intercarinal surfaces finely and sparsely granular; VL and VM carinae complete, granular; VL and VSM carinae fused, only separated medially (fig. 20E); ventral intercarinal surfaces granular; three pairs of VL and VSM macrosetae; two pairs of macrosetae along posterior margin.

Telson: Length/height ratio: ♂, 2.53–3.06 (n 5 2); ♀, 2.3 (n 5 1). Vesicle elongated (♂, fig. 22H) or oval (♀, fig. 24F); dorsal surface smooth, slightly concave medially, gland not apparent (♂); ventral surface coarsely granular. Aculeus short and curved, more so in ♀.

Hemispermatophore: Apex very well developed; distal crest almost straight, well developed, restricted to distal half of apex. Frontal crest weakly developed, less than half length of lamina; basal part oblique; distal part short, parallel to ventral margin of lamina, lateral projections slightly undulated with minute granulation. Basal lobe, terminal process extending almost to median part of frontal crest (fig. 47C, D).

DISTRIBUTION: All known records of this species are located in the Pampa del Tamarugal of Iquique Province, Region I (Tarapacá), Chile (figs. 3A, 53).

ECOLOGY: The Pampa del Tamarugal is a desert area characterized by the near absence of rainfall (0.2–1 mm per year), high-salinity soils (mostly of alluvial origin from the Andes), depressions with salt lakes, and a forest dominated by Prosopis tamarugo and Prosopis chilensis (Mol.) Stuntz trees (fig. 3A). Prosopis tamarugo is a deciduous open-crowned tree up to 18 m tall, with a trunk up to 80 cm in diameter, a dense mat of lateral roots and a deep taproot (up to 6 m deep on trees 15 m tall; Habit et al., 1981; Serra, 1997). Temperatures in the Pampa del Tamarugal vary from ‾ 12 ° C during winter nights to 36 ° C on summer days, with a daily range of more than 35 ° C in summer. The salt lakes are dry, surface water is absent year-round, and the groundwater may be more than 60 m below the surface. The only humidity is provided by sporadic fog. Prosopis tamarugo forests occur only where groundwater is between 2–40 m below the surface ( Serra, 1997). Specimens of O. tamarugal were collected at night, with UV light detection, inside the forest. The two males collected were active on the surface, sitting below large trees. The females and juveniles were inactive, resting under large plates of hard soil and salt (one of the forests is located near a dry salt lake). Brachistosternus donosoi Cekalovic, 1974 , a larger and more active bothriurid species, was collected in sympatry.