Brachistosternus contisuyu, 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 : 170-176

Brachistosternus contisuyu n. sp.

( Figs. 1 , 2C , 12–15 ; Table 2 )

Type material. Holotype male: Peru, Arequipa Department, Islay Province, Lomas de Mejía , 530 m asl, (17°03'15" S; 71°52'44" W), 20/IV/1997, J. A. Ochoa coll. ( MUBI) . Paratypes: (same data as holotype), 1 male ( MACN) , 1 male, 1 female ( MUBI) . Peru, Arequipa Dept. , 20 km South Camaná, 500-1000 m asl, [16°41'01.93" S; 72°30'12.27" W], 7/VIII/1977, no coll., 3 males, 1 female ( MACN) .

Etymology. The specific name is a noun in apposition, taken from the Quechua Conti Suyu, and refers to the geographic distribution of this species in southwestern Peru. The Inca territory was divided into four administrative regions (suyus): Chinchay (NW), Anti (NE), Conti (SW), and Qolla (SE). The southwestern region, Conti Suyu, included parts of modern Ica, Arequipa, Moquegua and Tacna departments in Peru.

Diagnosis. Brachistosternus contisuyu n. sp. is a member of the subgenus Brachistosternus because of the trichobothrial pattern and the shape of the hemispermatophore. This species can be separated from all other species of lowlands, or intermediate altitudes of southern Peru, by the shape of its androvestigia, which are small and almost subcircular, whereas all other species of the area bear elongated androvestigia or, they do not bear androvestigia at all. Only Brachistosternus quiscapata Ochoa & Acosta (2002) bears relatively similar androvestigia, but the hemispermatophore of Brachistosternus contisisuyu n. sp. bears a more elongated and thinner distal lamina, and presents internal spines, which are absent in B. quiscapata ( Ochoa & Acosta 2002) .

Description. Based on the holotype male (MUBI) and paratypes (MACN; MUBI). Total length, males: 34.8– 52 mm, (N=5; mean= 42.9 mm); females: 34.6–54.8 mm (N=2). Colour: Base colour dark yellowish, with dark brown pigmentation pattern in pedipalps, carapace, tergites, metasoma and legs; the remaining yellowish without dark spots ( Figs. 12 A–C). Chelicerae with dense reticular pigmentation on the anterior margin of manus and the external margins of fingers. Carapace, anterior margin with reticular pigment, area surrounding the lateral ocelli black; with two broad dark stripes from the postocular furrow to the lateral ocelli, ocular tubercle black, with a small subtriangular unpigmented area in front of the ocular tubercle, with two posterolateral dark spots. Tergites I– VI each with a single transverse stripe that covers most of each segment; tergite VII with an anteromedian triangular spot, and two well developed posterolateral dark spots. Sternites, sternum, genital opercula and pectines unpigmented. Metasomal segments: dorsal surface with a median anterior dark spot, and two posterolateral dark spots occupying the posterior third of the segment; lateral surfaces with faint reticular pigment; ventral surface unpigmented, except for segment V (in some specimens) with weak reticular pigmentation on the distal two thirds. Telson , vesicle unpigmented, aculeus dark brown. Pedipalps: trochanter unpigmented; femur with well developed stripes along DI, DE, and VE margins, with DI and DE joining in a big dark dorsal spot occupying almost half of the dorsal surface, near the articulation with patella. Patella, with dorsointernal, and dorsoexternal stripes, connected to each other by reticulate pattern on the dorsal surface; internal surface densely pigmented near the articulation with chela, ventral surface unpigmented. Chela with faint reticular stripes along DI, DM, DS, D, E, V and VM carinae; area near articulation of fixed and movable fingers, and base of fixed finger with faint pigment. Legs: coxae and trochanters unpigmented; femora densely pigmented; patellae pigmented along ventrointernal and dorsal margins; tibiae, basitarsi, and telotarsi unpigmented.

Chelicerae: anterior margin of movable fingers strongly curved; movable fingers with two small subdistal teeth, basal one bigger.

Pedipalps: Femur with DI, DE and VI carinae well developed ( Fig. 13F ), granular, extending the entire length of the segment, with two DE macrosetae; anterior margin with few scattered large granules and two macrosetae; rest of the intercarinal surfaces smooth. Patella, DI and VI carinae formed by a few scattered granules, remaining surfaces smooth, ( Figs. 13 G, H ); with two DI and two VI macrosetae. Chela manus ( Figs. 13 A–E) slender, length/ width ratio, males: 3.44–4.38 (N=5; mean=3.85), females: 4.40–4.76 (N=2); length/height, males: 2.88–3.48 (N=5; mean=3.26); females: 3.38–3.61 (N=2); with a blunt VM accessory carina, internal surface with slight bulge near articulation of movable finger (females) ( Fig. 13E ), or with a pronounced, subtriangular projection (males) ( Fig. 13A ); fingers elongated, with a median row of denticles, and five or six pairs of accessory denticles, the basal external denticle is usually part of the median row. Trichobothrial pattern neobothriotaxic major Type C, with one accessory trichobothrium in V series of chela; 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 27 trichobothria (Dt, Db, 5 Et, Est, Esb, 3 Eb, dt, dst, dsb, db, et, est, esb, eb, ib, it, 5 V), with Et 4 petite, Esb forming triangle with Eb 2 and Eb 3.

Carapace: anterior margin almost straight, with four setae and a medium sized median projection. Surface: smooth in the median area near the ocular tubercle; lateral and posterior margins slightly granular, more so in males. Anterior longitudinal sulcus, posterior longitudinal sulcus, and lateral sulci present and well developed. Median ocular tubercle well developed, placed in the middle of the carapace, interocular sulcus well developed, median ocelli well developed, facing towards the lateral margins, ca two diameters apart; with one seta behind each eye. Lateral ocelli pattern type 3A; with three small lateral ocelli on each side of carapace, two of them anteriorly, anterior one slightly above the posterior one, third ocellus similar in size to the other two, and slightly above them.

Legs: Surfaces smooth, except for the external surface of femur of leg IV which is slightly granular. Basitarsi each with two well developed pedal spurs, the internal one 50% smaller than the external one in leg I, about 30 % smaller in leg II, symmetrical in legs III and IV. Telotarsi elongated, ventrolaterally compressed, dorsally with a row of setae, ventrally each with a ventromedian row of scarce and strongly reduced hyaline setae, and paired rows of ventrosubmedian setae. Counts of setae on telotarsus of leg III: Dorsal setae: 10–12 (N=8; median=10); ventrosubmedian prolateral setae: 6–7 (N=8; median=7); ventrosubmedian retrolateral setae: 5–6 (N=8; median=5). Ungues shallowly curved and short, slightly asymmetrical in legs I and II, the internal one smaller; equal in length in legs III and IV.

Pectines: well developed, first median lamella more elongated in females. Tooth count, males: 31–36 (N=9; median=34); females: 25 and 30 (N=2).

Sternum: With two conspicuous subtriangular lateral lobes, each with a macroseta.

Genital opercula: Sclerites subtriangular, similar in males and females, but slightly wider in males.

Tergites: I–VI: with two anterior dorsosubmedian setae, surface smooth in the anterior margin; densely granular in the posterior half of the segment; tergite VII with two anterior dorsosubmedian setae, lateral and posterior margins densely granular; with two barley visible dorsosubmedian carinae in the posterior half of the segment, and two well developed lateral carinae extending the entire length of the segment.

Sternites: Surface smooth in females, finely granular in males; sternites III–VI with large and elongated spiracles and small and shallow ventrosubmedian furrows. Sternite VII finely granular in males, smooth in females.

Metasoma: Metasomal segment I, dorsal surface densely granular, except for the area next to the median sulcus that is smooth; DL carinae formed by a row of granules, and extending the entire length of the segment, with one median DL macroseta; lateral surfaces granular between DL and LM carinae, smooth between LM and LIM carinae; LM carinae extending the entire length of the segment; LIM carinae only present in the posterior half of the segment; with one LM seta in the middle of the segment and one LIM macroseta in the posterior third of the segment; ventrally without carinae, granular in males, smooth in females, with 2-2 VL setae and 2 posterior VSM setae. Metasomal segments II and III similar to segment I but less granular and with the LIM carinae becoming more diffuse. Metasomal segment IV, dorsal surface smooth, DL carina poorly developed and extending the entire length of the segment in males, reduced to some scattered granules in females, with one DL macroseta; lateral margins with scarce blunt granules, LM carinae reduced to some scattered granules with two or three LM macrosetae; accessory carinae poorly developed, LIM carinae absent, ventral surface smooth, with 30-36 scattered setae. Metasomal segment V comparatively stout; length/width ratio, males: 1.66–1.76 (N=5; mean=1.70); females: 1.73 and 1.82 (N=2); dorsal surface smooth, males with two small glands or androvestigia placed in the anterior half of the segment ( Fig. 14D ); DL carinae poorly developed but extending the entire length of the segment; LM carinae reduced to a row of granules and 6–8 macrosetae but extending the entire length of the segment; lateral margins granular, more so above the LM carina; LIM carinae absent, VL carinae well developed and extending the entire length of the segment, with 8–12 VL macrosetae; ventral surface smooth except for some scattered granules in the posterior third of the segment ( Fig. 14C ), without VM carina, ventral macrosetae arranged in five transverse rows, two near the anterior margin of four (sometimes two) macrosetae, and three rows of two macrosetae each (4-4-2-2-2 or 4-2-2-2-2).

Telson: Vesicle globose, slightly more globose in females; length/height ratio, males: 2.89–3.03 (N=5; mean=2.96); females: 2.66 and 3.09 (N=2); ventral surface granular; lateral margins with a shallow furrow; dorsal surface smooth and shallow, in males there is a conspicuous glandular subtriangular surface. Aculeus similar in size to the vesicle, shallowly curved ( Figs. 14A, B ).

Hemispermatophore: Basal Portion well developed. Distal Lamina well developed, only slightly curved medially ( Fig. 15A ), similar in length to the basal portion but much narrower; distal lobe (distal posterior flexure) medium sized, occupying less than a quarter of the distal lamina, distal crest elongated extending about a half of the distal lamina, but without transverse crests; left hemispermatophore: cylindrical apophysis of the basal lobe well developed ( Fig. 15B ), relatively thin, of a similar thickness in all its length, and with an acute tip, 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 represented by some blunt granules which are barely visible; basal triangle medium sized formed by three or four chitinous crests. Right hemispermatophore without a cylindrical apophysis ( Fig. 15C ), instead there is a small ILA, poorly chitinized, with some spines corresponding to the Row of Spines in its base, smooth in the upper median and upper apical areas, and with some spines in the anterior apical margin, similar in length to the laminar apophysis; the rest as left hemispermatophore.

Distribution. Brachistosternus contisuyu n. sp. appears to be endemic to the Lomas formation between Mejía and Camaná in the Arequipa Department of Southern Peru, recorder from 530–1000 m asl ( Fig. 1 ).

Ecology. This species has been collected in Lomas biotopes, in isolated patches of vegetation on hillsides below 1000 m, surrounded by desert. This formation, sustained by coastal fog, is present along the coast of northern Chile and southern Peru (Ochoa et al. 2011). The Lomas vegetation of Mejía is dominated by herbaceous shrubs and the tree Caesalpinia spinosa (Molina) ( Fabaceae ). Brachistosternus contisuyu n. sp. is sympatric with another bothriurid, Orobothriurus paessleri (Kraepelin, 1911) .

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 12A–D. Brachistosternus contisuyu n. sp., habitus. A. Male, dorsal aspect; B. Male, ventral aspect; C. Female, dorsal aspect; D. Female, ventral aspect. Scale bars: 1 cm.

FIGURES 13A–H. Brachistosternus contisuyu n. sp. A. Right pedipalp chela, male, internal aspect; B. Right pedipalp chela, male, ventral aspect; C. Right pedipalp chela, male, external aspect; D. Right pedipalp chela, male, dorsal aspect; E. Right pedipalp chela, female, ventral aspect; F. Left pedipalp femur, male, dorsal aspect. G. Right pedipalp patella, male, external aspect; H. Right pedipalp patella, male, ventral aspect. Scale bars: 1mm.

FIGURES 14A–D. Brachistosternus contisuyu n. sp. A. Metasomal segment V and telson, male, lateral aspect; B. Metasomal segment V and telson, female, lateral aspect; C. Metasomal segment V, male, ventral aspect; D. Metasomal segment V, male, dorsal aspect. Scale bars: 1mm.

FIGURES 15A–C. Brachistosternus contisuyu 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.

Tables

TABLE 2. Measurements (mm) of Brachistosternus anandrovestigia n. sp. (holotype and paratype, MUBI); Brachistosternus contisuyu n. sp. (holotype MUBI, paratype MACN) and Brachistosternus misti n. sp. (holotype and paratype, MUBI).

	Brachistosternus anandrovestigia n. sp.		Brachistosternus contisuyu n. sp.		Brachistosternus misti n. sp.
	Male holotype Female paratype		Male holotype	Female paratype	Male holotype	Female paratype
Total length	43.13	44.64	37.03	54.79	62.36	60.48
Carapace, length	4.85	5.98	5.10	7.82	7.92	7.92
Carapace, anterior width	3.55	4.26	3.59	5.21	5.09	5.17
Carapace, posterior width	5.25	5.98	4.83	7.98	7.92	7.59
Mesosoma, total length	14.18	14.67	9.17	13.85	16.3	15.97
Metasoma, total length	18.28	21.96	17.38	26.66	30.33	28.19
Metasomal segment I, length	3	3.5	2.69	4.44	4.44	4.44
Metasomal segment I, width	3.04	3.68	2.62	4.12	4.04	4.04
Metasomal segment I, height	2.4	2.84	2.48	3.39	4.68	3.72
Metasomal segment II, length	3.4	4	3.10	4.93	5.25	5.25
Metasomal segment II, width	2.76	3.28	2.55	3.88	3.72	3.88
Metasomal segment II, height	2.4	2.76	2.41	3.31	4.04	3.55
Metasomal segment III, length	3.48	4.40	3.45	5.25	6.38	5.49
Metasomal segment III, width	2.60	3.12	2.55	3.72	3.55	3.72
Metasomal segment III, height	2.36	2.64	2.34	3.23	3.96	3.47
Metasomal segment IV, length	4.00	4.80	3.79	5.90	6.70	5.74
Metasomal segment IV, width	2.40	2.96	2.48	3.55	3.23	3.72
Metasomal segment IV, height	2.16	2.40	2.14	2.91	3.88	3.15
Metasomal segment V, length	4.40	5.16	4.34	6.14	7.51	7.27
Metasomal segment V, width	2.52	3.00	2.62	3.55	3.07	3.72
Metasomal segment V, height	1.80	2.24	2.07	2.59	3.79	2.99
Telson , length	5.82	7.03	5.38	6.46	7.75	8.40
Vesicle,length	3.60	4.04	3.45	4.04	4.68	4.85
Vesicle, width	2.18	2.50	2.21	2.99	3.07	3.31
Vesicle, height	1.86	2.18	1.86	2.42	2.66	2.58
Aculeus, length	2.22	2.99	1.93	2.42	3.07	3.55
Femur, length	3.88	3.63	3.93	3.65	6.30	5.49
Femur, width	1.13	1.29	1.10	1.61	1.69	1.70
Patella, length	3.64	3.80	3.79	5.25	5.17	5.25
Patella, width	1.37	1.61	1.45	2.10	2.42	2.10
Chela, length	6.99	7.19	7.10	9.61	10.80	9.94
Chela, width	1.78	1.78	2.00	2.02	2.70	2.28
Chela, height	2.26	2.42	2.21	2.66	3.72	2.93
Movable finger, length	4.04	3.72	4.07	5.57	6.30	5.54