Megachactops kuemoi, Ochoa & Rojas-Runjaic & Pinto-da-Rocha & Prendini, 2013

Ochoa, José A., Rojas-Runjaic, Fernando J. M., Pinto-da-Rocha, Ricardo & Prendini, Lorenzo, 2013, Systematic Revision Of The Neotropical Scorpion Genus Chactopsis Kraepelin, 1912 (Chactoidea: Chactidae), With Descriptions Of Two New Genera And Four New Species, Bulletin of the American Museum of Natural History 2013 (378), pp. 1-121 : 112-116

Megachactops kuemoi , n. sp.

Figures 2 , 4A , 5F , 9E , 64C, D , 65C, D , 67B, C , 68B , 69C, D , 73–76 ; table 5

TYPE MATERIAL: VENEZUELA: Amazonas State: Municipio Autana: Holotype ³, 2 ♀ paratypes ( MHNLS), paratype ♀ ( MHNC), Tobogán del Cuao, 05 ° 059580 N 67 ° 299540W, 124 m, 14–15.vii.2010, F. Rojas- Runjaic ; 1 ♀, 1 subad. ♀ paratypes ( AMNH), 1 subad. ♀ paratype ( AMNH [ LP 9230 ], 2 juv. paratypes ( AMNH [ LP 9244 , 9247 ]), paratype ♀ ( MHNC), Autana, near base of tepui Autana, 04 ° 48910.380 N 67 ° 29910.260W, 84–90 m, 9.x.2008, S. Bazó, rainforest; paratype ³ ( AMNH [ LP 5203 ]) ex E. Ythier, xi.2005. Municipio Atures: 1 juv. ³ paratype ( MHNLS), road Puerto Ayacucho – Gavilán, between La Reforma and Danto communities, 05 ° 34945.30 N 67 ° 32944.60W, 91 m, 18.vii.2010, F. Rojas-Runjaic.

ETYMOLOGY: The specific name is a noun in apposition, referring to an Amazonian deity who created all dangerous and poisonous creatures of the night, from the folklore of the Piaroa of Venezuelan Amazonia.

DIAGNOSIS: Megachactops kuemoi , n. sp., may be distiguished from M. coriaceo , n. comb., as follows. Megachactops kuemoi , n. sp., is in general less granular, with less pronounced carination (figs. 64A, B, 66, 68A, 69A, B). The carapace is coarsely granular (more so in ³) with some smooth, punctate surfaces, the pedipalp patella intercarinal surfaces mostly smooth and punctate, and the ventral intercarinal surfaces of metasomal segments I–V and lateral and ventral surfaces of the telson (³) mostly smooth and punctate in M. kuemoi , n. sp. (figs. 64C, D, 67B, C, 68B, 69C, D), whereas the carapace is entirely finely and densely granular, the pedipalp patella intercarinal surfaces mostly finely granular, the ventral intercarinal surfaces of metasomal segments I–V densely granular, and the lateral and ventral surfaces of the telson (³) finely granular in M. coriaceo , n. comb. The pedipalp chela carinae are coarsely and sparsely granular in M. kuemoi , n. sp., but more finely and densely granular in M. coriaceo , n. comb. The pedipalp patella EM carina is complete and granular in M. kuemoi , n. sp., but obsolete, obscured by dense granulation in M. coriaceo , n. comb. The DSM carinae, absent on metasomal segments I–III in M. kuemoi , n. sp., are present in M. coriaceo , n. comb. The DL and ML carinae of metasomal segments I–IV, obsolete in M. kuemoi , n. sp., are pronounced in M. coriaceo , n. comb. The VM carinae are absent on metasomal segments I–IV, and the VSM carinae absent in the anterior third of segment V, in M. kuemoi , n. sp., whereas the VM carinae are present in the anterior half of segments III and IV, and the VSM carinae present in the anterior third of segment V in M. coriaceo , n. comb. Other differences between the two species are as follows: the pectines and coxosternal region are sparsely covered with microsetae (especially in ♀) in M. kuemoi , n. sp., but densely covered in M. coriaceo , n. comb.; pedipalp chela trichobothrium eb is situated proximal to the base of the fixed finger in M. kuemoi , n. sp., and subproximal in M. coriaceo , n. comb.

DESCRIPTION: Based on the holotype ³ and several paratype ♀♀. Measurements of a holotype ³ and a paratype ♀ recorded in table 5 .

Total length: ³, 56.8 mm; ♀, 65.87– 67.94 mm (n 5 4; mean 5 66.62).

Color: Base color mostly brown with dark brown spots (fig. 5F); coxosternal region, pectines, and sternites III–V pale brown with brown spots; aculeus slightly darker terminally. Cheliceral manus, dorsal surfaces with fine reticulate pigmentation, becoming contiguous distally near base of fixed finger; fixed and movable fingers entirely pigmented. Carapace densely pigmented throughout; median ocular tubercle and surfaces around lateral ocelli very densely pigmented; anteromedian longitudinal sulcus densely pigment- ed, posteromedian longitudinal and postocular sulci faintly pigmented, with submedian pigmentation converging medially. Pedipalp femur, dorsal and internal surfaces densely pigmented, ventral and external surfaces faintly pigmented, with pigmentation stripes along EM and VM carinae; patella, dorsal and internal surfaces densely pigmented, ventral surface mostly unpigmented, with faint pigmentation stripes along VI and VE carinae, external surface with broad faint pigmentation stripe along EM carina and irregular faint pigmentation throughout; chela with pigmentation stripes along D, SD, DS, DMA, DI, E, IM, VI, and VE carinae, contiguous at base of fingers; fingers densely pigmented. Legs, prolateral surfaces densely pigmented, retrolateral surfaces faintly pigmented. Tergites densely pigmented throughout. Coxosternal region, genital operculum and pectines faintly pigmented. Sternites III–V faintly pigmented medially, more densely pigmented laterally; V with unpigmented subtriangular area medially; VI and VII densely pigmented throughout. Metasomal segments I–IV, dorsal surfaces each with pigmentation stripes along DSM and DL carinae, surfaces between DSM carinae densely pigmented, pigmentation contiguous with that along posterior margins of segment, with additional fine reticulate pigmentation submedially; lateral surfaces each with pigmentation stripes along ML carinae, surfaces between DL and ML carinae with reticulate pigmentation, surfaces between ML and VL carinae with reticulate pigmentation in anterior half of segment, densely pigmented in posterior half; ventral surfaces each with paired pigmentation stripes along VL carinae, becoming broader posteriorly, surfaces between VL and VSM carinae with reticulate pigmentation in anterior half, surfaces between VSM carinae densely pigmented, forming broad stripe, contiguous with lateral pigmentation in posterior half of segment I and posterior third of II–IV. Metasomal segment V densely pigmented on all surfaces; dorsal surface with reticulate DSM pigmentation in anterior half of segment, narrow DM pigmentation stripe connected to DSM pigmentation by fine reticulate pigmentation, pigmentation stripes along DL carinae, and dense pigmentation between DSM and DL pigmentation; lateral surfaces with reticulate pigmentation between ML and DL carinae, and pigmentation stripes along ML carinae, surfaces between ML and VL carinae with reticulate pigmentation in anterior half of segment and densely pigmented in posterior half; ventral surface with three dense pigmentation stripes along VM and paired VL carinae, contiguous in posterior third of segment, and with fine pigmentation stripes along VSM carinae in anterior half, contiguous with lateral pigmentation in posterior half and with VM pigmentation stripe in posterior third. Telson vesicle, dorsal surface densely pigmented; ventral surface with two broad VL and one narrow VM pigmentation stripes, separated by two narrow, unpigmented stripes.

Chelicerae: Manus, dorsoexternal surfaces sparsely setose, ventral and internal surfaces densely setose. Fixed finger with four teeth. Movable finger with five teeth on dorsal margin and two teeth on ventral margin; ventral surface with vestigial serrula, restrict- ed to ventral distal tooth.

Carapace: Anterior margin with deep, biconcave median notch and several microsetae, more so in ³ (fig. 64C, D); posterior margin sublinear, with few microsetae. Surfaces coarsely granular throughout, especially on interocular, circumocular, anterolateral, and median lateral surfaces, granulation becoming more fine on posterolateral surfaces, nongranular surfaces punctate (³), or mostly smooth and punctate, interocular, circumocular, anterolateral, and median lateral surfaces sparsely granular (♀); scattered microsetae throughout. Anteromedian carinae well developed, granular, less so in ♀; posteromedian carinae obsolete. Ocular tubercle punctate, smooth (♀) or with few granules (³). Median ocelli one diameter apart. Anteromedian longitudinal sulcus smooth and punctate, with few granules along borders; postocular sulcus deep, smooth; posteromedian longitudinal sulcus smooth; posterolateral and posterior transverse sulci smooth with few granules along borders.

Pedipalps: Femur, length/width ratio, ³, 2.93 (n 5 1); ♀, 2.82–3.12 (n 5 5; mean 5 2.93); DE, DI, and VI carinae complete, granular (fig. 74A); EM carina vestigial, reduced to single distal granule; VM carina granular, restricted to proximal half of segment; VE carina vestigial, reduced to three or four granules proximally; IM carina reduced to several prominent, isolated granules on proximal two-thirds of segment; dorsal intercarinal surface coarsely granular medially, smooth and punctate elsewhere; other intercarinal surfaces smooth and punctate, except ventral surface weakly granular in anterior half (³). Patella, length/width ratio, ³, 2.45 (n 5 1); ♀, 2.25–2.40 (n 5 5; mean 5 2.34); DM carina granular, restricted to medial third of segment; DE, DI, and VI carinae complete, granular, weakly developed medially (fig. 74B–D); EM carina weakly granular, absent (♀) or restricted to distal 80 % of segment (³); VE carina complete, weakly granular; DPP comprising prominent mound of three or four granules, associated with row of small granules on proximal twothirds of segment; VPP less developed, comprising prominent mound of two granules, associated with two granules medially on segment; dorsal intercarinal surface smooth and finely punctate, except for scattered weak granules on distal half of segment (³); external and internal intercarinal surfaces smooth and finely punctate, except for few weak granules medially (³); ventral surfaces smooth and finely punctate. Chela manus slightly incrassate, fingers relatively elongated (fig. 75); chela length/ width ratio, ³, 4.05 (n 5 1); ♀, 3.89–4.09 (n 5 5; mean 5 3.99); length/height ratio, ³, 4.25 (n 5 1); ♀, 3.75–4.04 (n 5 5; mean 5 3.90). Manus and fingers, intercarinal surfaces almost smooth, slightly punctate, and sparsely covered with microsetae, becoming more numerous on fingers; carinae obsolete, evident as subtle differences in angles between surfaces and weak granulation, more pronounced in ³; D carina discontinuous, complete on manus, obscured by granulation on proximal quarter of fixed finger, and weakly costate on distal three-quarters; SD carina granular, restricted to proximal quarter of manus; DS carina complete, weakly granular on manus, becoming costate on fixed finger; DMA carina weakly granular on manus, weakly costate on fixed finger; DI carina discontinuous, interrupted by two porous areas at base of fixed finger, granular on manus, weakly costate on distal threequarters of fixed finger; E carina complete, weakly granular (³) or obsolete (♀); VE, VI, and IM carinae complete, weakly granular. Fixed finger, median denticle row continuous, complete; flanked by 10 external and 10 internal denticles; internal accessory denticles arranged in three rows, first row continuous in proximal half of finger, discontinuous in distal quarter, and interspersed with internal denticles, second and third rows each comprising 25 or 26 denticles, discontinuous, restricted to distal two-thirds of finger; external accessory denticles arranged in two rows, one adjacent to median row, continuous in proximal 90 % of finger, second (externalmost) row, discontinuous in proximal half and continuous on distal half of finger, interspersed with external denticles.

Trichobothria: Femur with three trichobothria (fig. 70A). Patella with 33 trichobothria (fig. 70B–D): two dorsal, seven ventral, 23 external, one internal; v 1 –v 7 aligned and situated close to VE carina; est 5 situated on external surface near VE carina, distal to est 4; est 3 situated slightly proximal or distal to est 4; em 3 usually situated proximal to em 1 and em 2; esb 2 situated distal to or in same axis as esb 3. Chela with 26 trichobothria (fig. 71): 10 situated on manus, three ventral, seven external; 16 situated on fixed finger, seven external, six dorsal, three internal; isb absent; it situated between et 3 and est; Est situated equidistant between V 3 and Et 1; Et 2 situated in same axis as Et 1; Esb situated proximal to Eb 2; eb situated proximal to base of fixed finger; db situated slightly distal to esb (in same axis as esb observed in one case); dm 1 situated slightly proximal to et 3.

Legs: Prolateral and retrolateral surfaces smooth. Femur III, DI carina granular, restricted to distal half of segment; DE carina absent or vestigial, comprising few small granules distally; EM carina complete, weakly granular on proximal half, obsolete distally; VI carina complete. Patella III, DI carina complete, weakly developed; VI carina restricted to distal half of segment, weakly developed; other carinae absent; dorsal surface with small porous area proximally, retroventral margin with two porous areas, small area situated proximally, elongated area situated on distal half. Basitarsus III setose; prodorsal margin with two small porous areas, one situated proximally, one distally; dorsal margin with several small subspiniform granules on proximal twothirds of segment; one dorsal and two ventral rows of small brushlike spinules, retrodorsal and proventral rows restricted to distal third of segment, ventromedian row restricted to distal two-thirds. Telotarsus III setose, pro- and retroventral rows each with 7–7 elongat- ed macrosetae.

Tergites: Pretergites I– VII, surfaces punctate. Posttergites I– VI, surfaces smooth in anterior half, becoming coarsely granular in posterior half, more so on IV – VI (³) or almost smooth and finely punctate, posterior margin with transverse row of small granules (♀) ; dorsomedian and dorsosubmedian carinae absent on III – VI. Posttergite VII, surface mostly smooth with slight granulation in places (³) or entirely smooth and punctate (♀) ; dorsomedian and dorsosubmedian carinae forming three, weakly granular mounds; dorsolateral carinae granular (³) or obsolete (♀); posterior margin with transverse row of granules.

Sternum: Ventral surface with 12 or 14 macrosetae, one pair situated anteriorly, and five or six pairs on posterolateral lobes; apex and anterior margins with several microsetae (fig. 65C, D).

Pectines: Pectinal tooth count: ³, 9/9 (n 5 2); ♀, 8 (1), 9 (1), 10 (10) (fig. 65C, D).

Sternites: Sternites III–VII, surfaces smooth, punctate; VII, acarinate.

Metasoma: Segments I–IV, intercarinal surfaces smooth and finely punctate, with small porous area posteriorly at LIM position; DSM carinae absent; DL carinae complete, coarsely granular on segments I– III, obsolete in IV; ML carinae complete, granular on segments I–IV; LSM carinae absent; LIM carinae each comprising single anterior granule on segment I, absent on II– IV; VL carinae complete, obsolete, granular; VSM carinae complete, obsolete, costate on segments I and II, incomplete (discontinuous medially) on III, incomplete, granular, more pronounced in posterior third on IV; VM carinae each represented by single granule medially on segment IV. Segment V, length/width ratio: ³, 2.36 (n 5 1), ♀, 2.15– 2.29 (n 5 5; mean 5 2.22) ; length/height ratio: ³, 2.60 (n 5 1), ♀, 2.45–2.67 (n 5 5; mean 5 2.61); ventral intercarinal surfaces sparsely granular in posterior third, other intercarinal surfaces smooth; small porous area posteriorly at LIM position; DL carinae complete, obsolete, granular; LSM and LIM carinae absent; ML carinae moderately developed, granular, restricted to anterior third; VL carinae well developed, complete, granular; VM carina complete, granular (fig. 68B).

Telson: Length/height ratio, ³, 3.16 (n 5 1); ♀, 3.24–3.71 (n 5 5, mean 5 3.41). Vesicle slightly elongated; dorsal surfaces smooth; lateral and ventral surfaces finely and sparse- ly granular, nongranular surfaces sparsely punctate (³) or coarsely and sparsely granular, more so ventrally, nongranular surfaces densely punctate (♀) (fig. 69C, D), with few macrosetae and scattered microsetae. Aculeus short, gently curved.

Hemispermatophore: Similar to M. coriaceo , n. comb. Apex short, curved to ventral surface, tapering distally (fig. 76A–C); flagellum short, curved; ental margin slightly undulate distally; ental fold short, subtriangular, situated at base of apex; pedicel elongated. Trunk well developed, strongly tortuous medially, sheath-shaped part approximately onethird the length of trunk; ventral concavity well developed; foot unknown. Lobe region well developed, with two lobes; ental lobe elongated, terminating in strongly sclerotized apophysis; median lobe auriculate, extending entally and ventrally, approximately 80 % the length of lamina, distal margin slightly folded, dorsal margin well sclerotized, with row of small spines medially, dorsal surface finely papillose, ventral surface strongly sclerotized, apapillose; median trough deep, extending entire length of median lobe.

DISTRIBUTION: Megachactops kuemoi , n. sp., is endemic to the state of Amazonas, Venezuela (fig. 2).

HABITAT: Megachactops kuemoi , n. sp., inhabits primary rainforest in the Orinoco River basin (fig. 4A).

Figures

Fig. 2. Distribution of Chactopsoides, n. gen., and Megachactops, n. gen., plotting known locality records in Brazil, Colombia, and Venezuela. Chactopsoides anduzei (González-Sponga, 1982), n. comb., solid squares; Chactopsoides gonzalezspongai, n. sp., solid diamond; Chactopsoides marahuacaensis (González-Sponga, 2004), n. comb., open square; Chactopsoides yanomami (Lourenço et al., 2011), n. comb., solid circle; Megachactops coriaceo (González-Sponga, 1991), n. comb., open diamond; Megachactops kuemoi, n. sp., open circle; undetermined Chactopsoides species, solid stars.

Fig. 4. Chactopsoides, n. gen., and Megachactops, n. gen., habitat. A. Autana, Amazonas, Venezuela, habitat of Chactopsoides anduzei (González-Sponga, 1982), n. comb., and Megachactops kuemoi, n. sp. B. Isla Piñate, confluence of Orinoco and Ventuari rivers, Amazonas, Venezuela, habitat of Chactopsoides gonzalezspongai, n. sp.

Fig. 5. Chactopsis Kraepelin, 1912, Chactopsoides, n. gen., and Megachactops, n. gen., habitus in life. A, B. Chactopsis amazonica Lourenço and Francke, 1986, Reserva Ducke, Manaus, Amazonas, Brazil. A. ³. B. ♀. C. Chactopsoides anduzei (González-Sponga, 1982), n. comb., ³, Isla Ratón, Amazonas, Venezuela. D. Chactopsoides gonzalezspongai, n. sp., ³, Isla Piñate, Amazonas, Venezuela. E. Chactopsis insignis Kraepelin, 1912, ³, Tahuayo River, Loreto Department, Peru. F. Megachactops kuemoi, n. sp., ♀, Tobogan del Cuao, Amazonas, Venezuela.

Fig. 9. Chactopsis Kraepelin, 1912, Chactopsoides, n. gen., and Megachactops, n. gen., dextral pedipalp chela, movable finger, dorsal aspect showing dentition. A. Chactopsis curupira, n. sp., paratype ³ (MZSP). B. Chactopsis insignis Kraepelin, 1912, ³ (MHNC). C. Chactopsoides anduzei (González-Sponga, 1982), n. comb., ³ (AMNH). D. Chactopsoides gonzalezspongai, n. sp., paratype ³ (AMNH). E. Megachactops kuemoi, n. sp., paratype ♀ (MHNC). Scale bars 5 1 mm.

Fig. 64. Megachactops, n. gen., carapace, dorsal aspect. A, B. Megachactops coriaceo (González- Sponga, 1991), n. comb. A. Holotype ³ (MAGS). B. Paratype ♀ (MAGS). C, D. Megachactops kuemoi, n. sp. C. Holotype ³ (MHNLS). D. Paratype ♀ (AMNH). Scale bars 5 1 mm.

Fig. 65. Megachactops, n. gen., sternum and pectines, ventral aspect. A, B. Megachactops coriaceo (González-Sponga, 1991), n. comb. A. Holotype ³ (MAGS). B. Paratype ♀ (MAGS). C, D. Megachactops kuemoi, n. sp. C. Holotype ³ (MHNLS). D. Paratype ♀ (AMNH). Scale bars 5 1 mm.

Fig. 67. Megachactops, n. gen., metasomal segments III–V (A, B) or IV and V (C), lateral aspect. A. Megachactops coriaceo (González-Sponga, 1991), n. comb., paratype ♀ (MAGS). B, C. Megachactops kuemoi, n. sp. B. Holotype ³ (MHNLS). C. Paratype ♀ (AMNH). Scale bars 5 1 mm.

Fig. 68. Megachactops, n. gen., metasomal segments III–V, ventral aspect. A. Megachactops coriaceo (González-Sponga, 1991), n. comb., paratype ♀ (MAGS). B. Megachactops kuemoi, n. sp., holotype ³ (MHNLS). Scale bars 5 1 mm.

Fig. 69. Megachactops, n. gen., telson, lateral aspect. A, B. Megachactops coriaceo (González-Sponga, 1991), n. comb. A. Holotype ³ (MAGS). B. Paratype ♀ (MAGS). C, D. Megachactops kuemoi, n. sp. C. Holotype ³ (MHNLS). D. Paratype ♀ (AMNH). Scale bars 5 1 mm.

Fig. 73. Megachactops kuemoi, n. sp., habitus. A, B. Holotype ³ (MHNLS). C, D. Paratype ♀ (AMNH) A, C. Dorsal aspect. B, D. Ventral aspect. Scale bar 5 10 mm.

Fig. 74. Megachactops kuemoi, n. sp., holotype ³ (MHNLS), dextral pedipalp segments. A. Femur. B–D. Patella. A, B. Dorsal aspect. C. External aspect. D. Ventral aspect. Scale bar 5 1 mm.

Fig. 75. Megachactops kuemoi, n. sp., dextral pedipalp chela. A. Holotype ³ (MHNLS). B–E. Paratype ♀ (AMNH). A, C. External aspect. B. Dorsal aspect. D. Ventral aspect. E. Internal aspect. Scale bar 5 1 mm.

Fig. 76. Megachactops kuemoi, n. sp., holotype ³ (MHNLS), sinistral hemispermatophore. A. Ental aspect. B. Dorsal aspect. C. Ectal aspect. Scale bar 5 1 mm.