Heteroctenus Pocock, 1893

Figures 1 A, 2 A, B, 3, 4, 11A, B, 12B, 14A–E, 17A, 18A–E, 21A, B, 22A, B, 23A–N, 25–35

Scorpio junceus Herbst, 1800 (= Heteroctonus junceus (Herbst, 1800)), type species by subsequent designation.

Scorpio (part): Herbst, 1800: 65 –67, pl. III, fig. 2; Latreille, 1804: 126, 127.

Scorpio (Atreus) (part): Gervais, 1843: 130;

1844 a: 218, fig. 18; 1844b: 39, 54; Lucas, 1851: 70, pl. V, fig. 5–5c; Gervais, 1859: 41, pl. I, fig. 2, 2a–b.

Rhopalurus (part): Karsch, 1879b: 119, 121, 122; Pocock, 1902a: 36 –38, pl. VIII, fig. 5, 5a, pl. IX, fig. 1, 1a; Banks, 1909: 172; Herrera, 1917: 271; Lampe, 1917: 197; Franganillo, 1930a: 95, figs. 19–21; 1930b: 119; Mello- Leitão, 1932: 14, 15; Meise, 1934: 29, 32, 38; Franganillo, 1935: 21; 1936: 164, figs. 86, 87; Moreno, 1939a: 65 –67, pl. 6, fig. 3; 1939b: 124–128, pl. XIX–XXI; 1940b: 129–130, pl. XXII; Prado, 1940: 26 –28; Roewer, 1943: 219; Jaume, 1954: 1090, 1091; Esquivel de Verde, 1968: 67; Esquivel de Verde and Machado-Allison, 1969: 33; Bücherl, 1971: 327; Armas, 1973: 7; 1974 b: 2–6, figs. 1A, B, 2A, B, 3A, B, 4, table 1; 1977: 3; Stahnke and Calos, 1977: 119; Lourenço, 1979: 215, 216, fig. 8; Armas, 1981a: 52; 1981 b: 2–5, figs. 1, 2, table 1; 1982a: 4; 1982b: 5, table 2; Lourenço, 1982a: 108, 110–112, 114–116, 134–138, figs. 2–11, 14–24, 78, table 1; Armas, 1983: 3, fig. 1; 1984: 8; Lourenço, 1984a: 169, 170; 1986a: 133, 135, 136, figs. 17, 18; 1986b: 165, fig. 7; Armas and Marcano Fondeur, 1987: 19, 20, 23, pl. II, fig. 4, tables 10, 11; Armas, 1988: 68 –71, 93, 97, figs. 27, 36; Lourenço, 1992: 55; Rudloff, 1994: 9; Lourenço and Cloudsley-Thompson, 1995: 424, 426; Lourenço, 1997a: 590; Lourenço and Pinto-da-Rocha, 1997: 181; Kovařík, 1997: 181; 1998: 118; Armas, 1999: 127; Armas et al., 1999: 30 –32; Lourenço et al., 2000: 141 –143; Fet and Lowe, 2000: 217, 219–221; Armas, 2001: 246, table 1; Fet et al., 2003a: 2, 3, 6, 10, table 1; Teruel, 2003: 149, 150, figs. 1, 2; 2005: 165; Teruel and Montano, 2005: 221 –223, 225–227, figs. 10, 14, tables 2, 4; Armas, 2006: 6; Teruel, 2006: 43 –53, figs. 1–10, 12A, E, tables 1, 2; Teruel and Armas, 2006: 175 –179, figs. 1–4, tables 1, 2; Teruel et al., 2006: 219 –223, fig. 1; Lourenço, 2007: 359, 361, 362; Kamenz and Prendini, 2008: 9, table 2, pl. 41, 43; Perez- Gelabert, 2008: 68; Volschenk et al., 2008: 654, 658, 659, 663, 664, 674, fig. 1B, tables 1, 2; Prendini et al., 2009: 206 –223, figs. 1, 2, 4, 5A, B, E, F, 6A, C, 7A, C, 8, 10, 11, tables 1, 3; Santiago-Blay, 2009: 115, 116, 119, 122, 125, figs. 10, 31; Teruel and Armas, 2012 a: 153 –167, figs. 1–16, tables 1 –7; 2012b: 209, 210, 212, 214–217, figs. 1–7, tables 1–3; Teruel and Kovařík, 2012: 116 –141, figs. 29, 40, 41, 48, 253–305, 534– 565, 636; Rodríguez-Cabrera and Teruel, 2014: 121; Lourenço and Armas, 2015: 228, 229; Rodríguez-Cabrera et al., 2015: 85, 86, fig. 1; Santos et al., 2016: 3, 9, tables 1, figs. 1Ñ, 2B, 3D.

Centrurus (part): Karsch, 1879b: 121, 122; Kraepelin, 1891: 123, 135–137, 139, figs. 30, 33; Pocock, 1893: 385, 391; Thorell, 1893: 372, 373; Kraepelin, 1895: 95; 1899: 89, 94, 95; 1901: 270; 1908: 187, 190, 193, 194; Werner, 1927: 357.

Heteroctenus Pocock, 1893: 375, 391, 392; Laurie, 1896: 131; Lönnberg, 1897: 197, 208.

Centruroides (Rhopalurus) (part): Werner, 1934: 274, fig. 33b.

DIAGNOSIS: Heteroctonus differs all from other rhopalurusine genera by the presence of a single, deep, median depression in the male pectinal plate. It differs further from Ischnotelson, gen. nov., Jaguajir, gen. nov., Physoctonus, Rhopalurus, Troglorhopalurus, and many species of Centruroides by the absence of a subaculear tubercle on the telson; from Centruroides, Ischnotelson, Physoctonus, and Troglorhopalurus by the presence of a pecten-sternite stridulatory organ (proximal pectinal teeth often enlarged, dorsal surfaces with multiple nodules and regular striations, sternite III, lateral margins forming smooth, raised carina, ventromedian carina elevated anteriorly, ventrosubmedian surfaces forming paired depressions, finely and irregularly granular); from Ischnotelson and Rhopalurus, by the separate (unfused) central lateral and posterior central submedian carinae of the carapace; from Centruroides by the presence of macrosetae on the dorsobasal surface of the pectinal teeth; from Ischnotelson, by the separate (unfused) lateral ocular and central lateral carinae of the carapace, and the telson vesicle not being laterally compressed; from Jaguajir by the separate (unfused) lateral ocular and anterior central submedian carinae of the carapace; from Physoctonus by the larger size (30–70 mm), the more distinct carapacial carinae, the setose proximal dorsal fulcra of the pectines, the incrassate pedipalp chela manus of the adult male, the bifurcate prolateral pedal spur of leg I, and the oblique subrows of primary denticles on the pedipalp chela fingers flanked closely by pro- and retrolateral accessory (supernumerary) denticles; and from Troglorhopalurus by the proximal dentate margin of the chela fixed and movable fingers of the adult male emarginate, with a distinct gap evident between them, when closed.

DESCRIPTION: The following general description outlines characters common to the species of Heteroctenus. Descriptions of hemispermatophores are based on H. abudi, H. bonettii, H. junceus, and H. princeps.

Total length: Large, robust scorpions (total length, 50–70 mm).

Color: Carapace and tergites I–VI light brown, tergite VII yellowish (fig. 1A). Coxosternal region, pectines and sternites pale yellow. Metasomal segments, dorsal surfaces yellow (segments I–III) to brown (IV and V); ventral surfaces darker; segments IV and V darker than preceding segments, with V darker than IV. Telson reddish brown, aculeus almost black. Chelicerae and legs yellowish. Pedipalps yellow with chela fingers darker than manus, reddish-brown.

Chelicerae: Base, dorsal surface with medial transverse row of well-developed tubercles.

Carapace: Median ocular tubercle raised (fig. 14A–E); two median ocelli; three pairs of lateral macroocelli; one or two pairs of lateral microocelli. Anteromedian, median ocular, and posteromedian sulci well developed, forming single, almost continuous, longitudinal sulcus. Lateral ocular, central lateral, anterior central submedian, and posterior central submedian carinae distinct, coarsely granular to costate-granular and separate (unfused).

Pedipalps: Pedipalp femur retrolateral accessory carinae absent. Pedipalp chela manus of adult male incrassate, fixed and movable fingers curved proximally (fixed finger curved dorsally, movable finger curved ventrally), such that proximal dentate margin emarginate, distinct gap present between fingers proximally, when closed (figs. 25–27), manus of female not incrassate, fixed and movable fingers not curved proximally, such that proximal dentate margin sublinear, little or no gap present between them proximally, when closed; manus, proventral and promedian (except in H. bonettii) carinae absent; fixed and movable fingers, median denticle rows each comprising eight or nine oblique subrows of primary denticles flanked closely by pro- and retrolateral accessory (supernumerary) denticles; movable finger with proximal lobe (fig. 17 A). Pedipalps orthobothriotaxic Type A, α configuration; femur with five dorsal trichobothria, trichobothrium d 2 situated on prolateral surface; patella trichobothrium d 3 situated retrolateral to dorsomedian carina; chela fixed finger trichobothrium db aligned with or distal to trichobothrium et.

Legs: Legs III and IV, tibial spurs absent; I–IV, basitarsi each with bifurcate prolateral pedal spur; telotarsi each with irregular tufts of fine, acuminate macrosetae.

Pectines: Pectinal plate with single median depression (male), anterior margin with sulcus (fig. 18A–E). Pectines often proximally expanded, at least 1.5× wider proximally than medially; proximal dorsal fulcra setose; pectinal teeth almost straight, slightly curved laterally, proximal teeth often enlarged, dorsal surfaces with multiple nodules and regular striations (figs. 11B, 12B), dorsobasal surfaces with macrosetae; pectinal sensillae peg shaped.

Mesosoma: Tergites IV–VI wider than I–III and VII (figs. 31–35); I–VI tricarinate, dorsomedian and dorsosubmedian carinae granular to costategranular, restricted to posterior half on I–VI, dorsosubmedian carinae more prominent on IV–VI. Tergite VII pentacarinate, dorsomedian carina restricted to anterior two thirds of segment. Sternites smooth, carinate obsolete, more developed on VI and VII; sternite III, lateral margins forming smooth, raised carina, ventromedian carina elevated anteriorly, ventrosubmedian surfaces forming paired depressions, finely and irregularly granular; respiratory spiracles (stigmata) width more than 5× length (fig. 11 A, B).

Metasoma: Metasoma robust, but not increasing markedly in width posteriorly, segment V slightly wider than I in adult male, I and V usually similar width in adult female (figs. 28–30). Segments I and II each with 10 distinct, costate-granular carinae, III and IV each with eight distinct, costate-granular carinae, V with seven distinct but less pronounced, granular carinae; dorsosubmedian carinae obsolete, reduced to rows of granules on dorsal surfaces of segments I–IV, more pronounced on segment I; dorsolateral carinae complete on segments I–IV, and terminating in prominent, spiniform granules posteriorly on III and IV, absent on V; lateral supramedian carinae complete on segments I–V; lateral inframedian carinae complete on segment I, partial on II, absent on III–V; ventrosubmedian carinae complete on segments I–IV, restricted to anterior third of V; ventromedian carina absent on segments I–IV, complete on V. Intercarinal surfaces finely to coarsely granular, less so on dorsal surfaces, especially on V.

Telson: Vesicle slightly elongate, length ca. 1.5× width, not laterally compressed, similar in width or slightly narrower than metasoma V; anterodorsal lateral lobes reduced or absent; lateral and ventral surfaces granular, with distinct ventromedian carina; subaculear tubercle absent.

Hemispermatophore: Flagelliform; flagellum, elongate and narrow (fig. 23A–N); trunk markedly concave; three lobules, ental (LI), ectal (LE), and basal (LB); LI continuous until flagellar base; flagellar base narrow, half (H. abudi and H. bonettii) to one-third (H. junceus and H. princeps) the maximum width of trunk; LE ca. half (H. abudi, H. junceus and H. princeps) to one third (H. bonettii) the length of LI and may be spiniform (H. bonettii); LB very short with sharp (H. abudi) or setalike (acuminate) (H. bonettii) tip.

INCLUDED SPECIES: Heteroctenus abudi (Armas and Marcano Fondeur, 1987), comb. nov.; Heteroctenus bonettii (Armas, 1999), comb. nov.; Heteroctenus junceus (Herbst, 1800); Heteroctenus garridoi (Armas, 1974), comb. nov.; Heteroctenus gibarae (Teruel, 2006), comb. nov.; Heteroctenus princeps (Karsch, 1879), comb. nov.

DISTRIBUTION: The species of Heteroctenus are endemic to the Greater Antilles of the Caribbean (figs. 3, 4): Cuba, Hispaniola (Haiti and the Dominican Republic), and Puerto Rico (Isla Mona). The known locality records range in altitudes from below sea level to 1200 m (Rodríguez-Cabrera and Teruel, 2014).

ECOLOGY: Whereas Heteroctenus primarily inhabit open vegetation formations (fig. 2A, B), in common with Rhopalurus and the South American genera (Lourenço, 1986a, 2008), they also occur in semideciduous forests (Armas, 2001). In the karst limestone landscapes where they occur, these lapidicolous scorpions shelter under stones or any other available surface debris.

REMARKS: This genus accommodates species previously assigned to Rhopalurus from the Greater Antilles, the monophyly of which was consistently recovered in the analyses by Esposito et al. (in review), resulting in four new combinations. Rhopalurus aridicola, R. melloleitaoi, and R. virkkii are newly synonymized based on morphological and, in the case of R. virkkii, molecular evidence. The validity of H. gibarae will need to be reassessed when material becomes available for study.