Chactopsoides, 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 : 84-88

Chactopsoides , n. gen.

TYPE SPECIES: Chactopsis anduzei González-Sponga, 1982 [5 Chactopsoides anduzei ( González-Sponga, 1982) , n. comb.].

ETYMOLOGY: The generic name reflects the similarity and close phylogenetic relationship with Chactopsis , and is masculine in gender.

DIAGNOSIS: Chactopsoides , n. gen., is most closely related to Chactopsis , from which it may be separated as follows. Pedipalp chelal trichobothrium ist is present and isb absent, it is situated between et 3 and est, Et 2 is situated distal to Et 1, and dm 1 is situated distal to et 3, in Chactopsoides , n. gen. (figs. 56, 60, 63), whereas ist is absent and isb present, it is situated between est and em, Et 1 and Et 2 are situated in the same axis, and dm 1 is situated proximal to or in the same axis as et 3, in Chactopsis (figs. 25, 28, 31, 34, 37, 40, 43). The hemispermatophore lamina is short and narrow in Chactopsoides , n. gen. (figs. 57, 61), but long and broad in Chactopsis (fig. 8). The hemispermatophore flagellum is slightly undulated (never curved) and the ental fold absent in Chactopsoides , n. gen., whereas the flagellum is curved or straight, and the ental fold present and distinct along the ental margin, noticeably toward the dorsal surface, in Chactopsis . The hemispermatophore trunk is elongated, the sheath-shaped portion extends more than two-thirds the length of the trunk, the foot extends almost the entire length of the trunk, the median longitudinal sulcus is present, and the ventral concavity reduced in Chactopsoides , n. gen., whereas the trunk is moderately or strongly tortuous medially, the sheath-shaped portion and the foot extend half or less than half the length of the trunk, the median longitudinal sulcus is absent, and the ventral concavity well developed in Chactopsis . The lobe region of the hemispermatophore is reduced, with a single, comparably short and weakly developed median lobe; the ental lobe absent, and the dorsal apophysis well developed, but laminar or folded in Chactopsoides , n. gen.; by contrast, the lobe region is well developed, with two lobes, the ental lobe is slightly sclerotized, forming a projection toward the ental surface, the median lobe is well developed, and the dorsal apophysis forms a sclerotized, crest- or horn-shaped projection in Chactopsis . The hemispermatophore of C. marahuacaensis , n. comb., and C. yanomami , n. comb., are unknown, but this species is included in Chactopsoides , n. gen., based on its pedipalp trichobothrial pattern.

Chactopsoides , n. gen., may be separated from Megachactops , n. gen., as follows. The carapace is acarinate and its anterior margin possesses a moderate to shallow median notch in Chactopsoides , n. gen. (fig. 45), whereas the carapace exhibits distinct median carinae, and its anterior margin possesses a conspicuous median notch, in Megachactops , n. gen. (fig. 64). The pedipalp patellar DM carinae are absent and the DPP present but weakly developed in Chactopsoides , n. gen. (fig. 55B), whereas the DM carinae are present and the DPP prominent in Megachactops , n. gen. (fig. 74B). Pedipalp patellar trichobothria v 6 and v 7 are situated submedially and out of alignment with v 1 – v 5, which are situated close to the VE carina, in Chactopsoides , n. gen. (fig. 55D), whereas v 6 and v 7 are aligned with v 1 – v 5 and situated close to the VE carina in Megachactops , n. gen. (fig. 74D). Pedipalp chela trichobothrium db is situated in the proximal third of the fixed finger, and V 3 is situated medially on the manus, equidistant between V 1 and V 4, in Chactopsoides , n. gen. (figs. 56, 60, 63), whereas db is situated medially on the fixed finger, and V 3 is situated in the distal third of the manus, closer to V 1 than to V 4 in Megachactops , n. gen. (figs. 71, 75). The VSM carinae of metasomal segment IV are complete and the VM carina absent in Chactopsoides , n. gen. (fig. 47), whereas the VSM carinae are partial and the VM carina present medially (well developed or vestigial) in Megachactops , n. gen. (figs. 66, 68). The ML carinae of metasomal segment V occupy more than half the length of the segment in Chactopsoides , n. gen. (fig. 51), but less than half its length in Megachactops , n. gen. (fig. 68). The hemispermatophore of the two genera differs as follows. The apex is elongated, the lobe region reduced to onefifth of the hemispermatophore length, with a single median lobe, usually papillose, the ental lobe absent, and the dorsal apophysis present, in Chactopsoides , n. gen. (figs. 57, 61), whereas the apex is short and subtriangular, the lobe region well developed, occupying a third of the hemispermatophore length, with two lobes, the dorsal apophysis absent, the ental lobe elongated, and the median lobe auriculate and almost apapillose, in Megachactops , n. gen. (figs. 72, 76).

DESCRIPTION: The following general description outlines characters common to all species of Chactopsoides , n. gen.

Total length: Small scorpions, ranging in total length from 21–35.5 mm.

Coloration: Varies from yellowish to brownish with dark spots.

Chelicerae: Manus, dorsoexternal surfaces sparsely setose; ventral and internal surfaces densely setose. Fixed finger, dorsal margin with four teeth (distal, subdistal, median, and basal), median and basal teeth fused into a bicusp. Movable finger, dorsal margin with five teeth (distal, two subdistal, median, and basal); ventral margin with two teeth (distal, subdistal); dorsal distal tooth smaller than ventral distal tooth; ventral surface with long, well-developed serrula.

Carapace: Anterior margin with moderate to shallow median notch (fig. 45). Posterior margin sublinear, usually with shallow medi- an notch. Surfaces mostly granular, especially in ³, more so on anterior third, ♀ less granular, mostly smooth, nongranular surfaces punctate; often with scattered microsetae; carinae absent or obsolete. Ocular tubercle well developed, slightly anteromedial; median ocelli well developed. Four pairs of lateral ocelli; anterolateral and median lateral pairs similar in size, approximately half the size of median ocelli; posterolateral pair smaller, approximately one-quarter the size of anterolateral and median lateral ocelli; dorsomedian pair greatly reduced, approximately one-quarter the size of posterolateral ocelli. Anteromedian longitudinal sulcus broad, well developed; postocular sulcus deep; posteromedian longitudinal and posterolateral sulci well developed; posterior transverse sulcus shallow.

Pedipalps: Patella, DM carina absent. Chela manus narrow and cylindrical, slightly more incrassate in ♀, with elongated fingers; nine carinae (D, SD, DS, DMA, DI, E, IM, VE, and VI) obsolete, usually identified by punctation, fine granulation, subtle differences in angles between adjacent surfaces, and/or pigmentation. Fixed finger carinae moderately developed, costate; two porous areas usually present proximally, in place of DI carina; dentition complex, median denticle row continuous, complete, flanked by 8 or 9 internal and external denticles in distal two-thirds, and numerous accessory denticles arranged in two to three rows, including at least one continuous row of external accessory denticles and at least one discontinuous row of internal accessory denticles.

Trichobothria: Femur with three trichobothria (figs. 55A, 59A, 62A): one external (e), one dorsal (d), one internal (i). Patella with 33 trichobothria (figs. 55B–D, 59B–D, 62B–D): two dorsal (d 1, d 2); seven ventral (v 1 –v 7), v 1 –v 5 situated close to VE carina, v 6 and v 7 situated submedially and out of alignment with v 1 – v 5; 23 external (et 1 –et 5, est 1 –est 5, em 1 –em 3, esb 1 – esb 4, eb 1 – eb 6); one internal (i). Chela with 26 trichobothria (figs. 56, 60, 63): 10 situated on manus, three ventral (V 1, V 3, V 4), seven external (Et 1 – Et 3, Est, Esb, Eb 1, Eb 2); 16 situated on fixed finger, seven external (et 1 – et 3, est, em, esb, eb), six dorsal (dt, dst, dm 1, dm 2, dsb, db), three internal (it, ist, ib).

Legs: Prolateral surfaces usually granular, retrolateral surfaces smooth. Tibial spurs absent. Pro- and retrolateral pedal spurs present. Basitarsi setose, each with dorsal and ventral rows of small brushlike spinules. Telotarsi setose, each with ventromedian row of elongated spinules, flanked by two paired rows of setae (pro- and retroventral and pro- and retrolateral); ungues well developed, curved, equal in length.

Sternum: Shape subpentagonal with two lateral lobes, and lateral margins converging anteriorly; posterior width greater than length; posterior depression deep (fig. 46).

Pectines: Pectinal plate, anterior margin with conspicuous median notch, lateral margins subparallel (♀) or converging posteriorly (³). Pectines each comprising four lamellae, proximal and marginal lamellae larger, subdistal and distal lamellae smaller; proximal lamella usually fused with subdistal lamella; fulcra absent. Tooth count, 7–11 (fig. 46).

Sternites: Sternites III–VI each with pair of small, oval spiracles, situated mediolaterally; surfaces usually smooth and punctate; VII with VL carinae obsolete.

Metasoma: Metasomal segments I–V (figs. 47–51), intercarinal surfaces densely granular, nongranular surfaces punctate; DL, ML, VL, VSM, and VM carinae distinct; DSM and LSM carinae absent or obsolete, LSM carinae often vestigial; DSM carinae usually present on segments I and II; DSM and DL carinae converging distally on segments I–III, subparallel on IV; DL and VL carinae complete on all segments; ML carinae complete on segments I–IV, variably developed on V; LIM carinae less developed, complete only on segment I; porous areas, usually forming raised mounds, present posteriorly in place of LIM carinae on segments II–IV; VSM carinae usually present on segments II–IV; VM carina variably developed on segment V.

Telson: Vesicle slightly elongated. Aculeus short, gently curved (fig. 52).

Hemispermatophore: Lamina narrow, slen- der, weakly sclerotized, especially distally (figs. 57, 61); apex elongated, curved, progressively tapering distally, and terminating in flagellum; frontal and distal crests absent; flagellum slightly undulated; ental fold absent; articular flexure present; slight proximal constriction forming moderately elongated pedicel. Trunk well developed, elongated; proximal part forming sheath-shaped base, well developed, with median longitudinal sulcus; distal part of ventral surface concave, reduced; foot well developed, extending almost entire length of trunk. Lobe region (capsule) complex, reduced, with single median lobe (figs. 57, 61); ental lobe absent; median lobe moderately developed, forming internobasal reflexion of sperm duct, sometimes with conspicuous median trough; dorsal apophysis well developed, laminar.

INCLUDED TAXA: Four species: Chactopsoides anduzei ( González-Sponga, 1982) , n. comb.; Chactopsoides gonzalezspongai , n. sp.; Chactopsoides marahuacaensis ( González-Sponga, 2004) , n. comb.; Chactopsoides yanomami ( Lourenço et al., 2011) , n. comb.

DISTRIBUTION: The known records of Chactopsoides , n. gen., fall within the state of Amazonas, Brazil, the state of Amazonas, Venezuela, and the department of Vichada, Colombia (fig. 2).

HABITAT: The known species of Chactopsoides , n. gen., inhabit primary tropical rainforest in the basins of the Orinoco and Rio Negro rivers (fig. 4).