Tityus uquirensis González-Sponga

Sousa, Leonardo De, Manzanilla, Jesús, Borges, Adolfo, Cornejo-Escobar, Pablo & Gregoriani, Tonio, 2008, Discovery and description of the male of Tityus uquirensis (Scorpiones: Buthidae) from the Paria Peninsula, northeastern Venezuela, Zootaxa 1828, pp. 57-68 : 58-64

Tityus uquirensis González-Sponga

Tityus uquirensis González-Sponga, 2001: 21 , 80–83, figs. 29–33, map 1

Eighteen specimens (4 adult males, 7 adult females, 7 juveniles) were examined for this work, which have been deposited at the “Colección de Escorpiones del Laboratorio de Toxinología” (CELT), Centro de Investigaciones en Ciencias de la Salud (CICS), School of Medicine, Universidad de Oriente (UDO), Anzoátegui State, Venezuela.

Definition and diagnosis. A large-sized Tityus species (males, 96.87 mm; females, 86.85 mm), characterized by the following combination of characters: (1) A marked sexual dimorphism, represented in the shape and length of the male pedipalps (slenderer than in females; female chelae two-fold wider than males); (2) Length of right pedipalp in males represents 66.80% of the total body length, while in females represents 46.45%; (3) Femur carinae poorly defined in males and better defined in females; (4) Array of dorsal femur trichobothria: (a) d3, d4 and d5 form a 180° angle in male and female, (b) Imaginary lines connecting segments d1-d3 with d3-d4 form an obtuse angle of 152° in male and 90° in female; (5) Each tergite possesses a posterior carina formed by irregularly spaced granules of variable sizes (poorly defined in males and better defined in females); (6) Dorsal carinae of metasomal segments I to IV formed by granules which size increases progressively towards the distal portion (poorly defined in males and better defined in females); (7) Dorsal surface of telson smooth; lateral surfaces with poorly defined, well spaced granules of variable sizes (both in male and female).

Tityus uquirensis differs from the other Tityus species inhabiting the Venezuelan northeast in the following characters: (1) the shape and length of the pedipalps, (2) total body length, (3) body color, and (4) the poorly defined pedipalp, leg, and metasomal carinae. T. uquirensis differs from T. quirogae (the other northeastern species with long and slender pedipalps) in: (1) body color, and (2) the poorly defined pedipalp, leg, and metasomal carinae.

Description, male of T. uquirensis ( Figs. 1–3 )

Based on CELT-508, adult specimens, collected by L. De Sousa and J. Manzanilla, 07/v/2002, near the ranger post, Paria Peninsula National Park, Las Melenas, Mariño Municipality, Sucre State, Venezuela (10º41´07´´ N and 62º37´16´´ W, 809 m altitude, GPS 45 Garmin®). 22.30 h, UV light, on trail creek.

Morphology. Carapace ( Fig. 2 a): anterior margin with a slight concavity, forming an obtuse angle. Wavy, almost straight, lateral and posterior margins. Carinae: anterior marginal carina formed by very small granules, some of which are vestigial; anterior paramedian carina formed by irregularly spaced granules of variable sizes which are connected to the supercilliary carina (the latter are smooth in the middle and granulose in their distal half); posterior paramedian carina nearly parallel, with small, closely spaced granules; marginal posterior carina with very small, well-spaced granules; oblique anterior carina slightly curved. Furrows: Anterior median furrow wide and shallow, slightly concave near the ocular median tubercle, with few and regularly spaced granules. Interocular furrow smooth, slightly concave. Posterior median furrow oval, deeper towards its distal portion. Posterior marginal furrow short and moderately deep. Posterior transversal furrows wide, flat and irregular, they divide into two branches in their distal portion. The remaining tegument is very irregular and poorly granulated, particularly in the region between the oblique anterior carina and the posterior transversal furrows. Chelicerae ( Fig. 2 b): reticulated coloration; chericeral dentition characteristic of the Buthidae . Pedipalps ( Figs. 2 c and 2d): with the typical trichobothrial pattern of Tityus (Orthobothriotaxic: Type A) ( Vachon 1974, Sissom 1990). Chela: slender and elongated, carinae poorly defined, with vestigial granules. Carinae located on the fingers are formed by small, well spaced granules. The fingers are long and narrow. Number of oblique lines of denticles on the movable finger (right chela): 18. Patella: dorsal and lateral external carinae formed by vestigial granules; ventral external carina poorly defined; lateral internal carina with an elevated basal denticle. There are pyramidal granules in the remaining carinae. The tegument between carinae is coriaceous. Femur: carinae poorly defined, with small granules; granules on the latero-dorsal internal surface are spiniform; tegument between carinae is coriaceous. Femur dorsal trichobothria d 3 to d 5 arranged in a straight line (180°) and form an obtuse angle of approximately 152° with d 1. Total length of right pedipalp: 72.90 mm. Total body length: 103.91 mm (pedipalp represents 70.16% of the specimen´s total body length). Ratio width/length of the chela: 2.31 mm / 31.07 mm = 0.07. Ratio length of movable finger/length of chela: 16.78 mm / 31.07 mm = 0.54. Legs: carinae of femur and patella well defined, with poorly defined granules. Pretarsus and basitarsus with smooth carinae. Tergites: sagital carina flat, without tubercles defined; carinae better defined towards the distal half of tergites I to III. In tergites IV to VI the carina increases progressively in length and granule definition until it occupies the entire area. In tergite VII, two smooth, paramedian carinae are present, with poorly defined granules which are convergent in the middle of the tergite and placed on a tegument elevation. Lateral carinae of tergites I to VI are curved and formed by granules of variable sizes, distributed irregularly. Carinae located in the posterior margin of the latter tergites are formed by granules of variable sizes, distributed irregularly, less defined in the male specimen than in the female. Tergite VII has two paramedian and two lateral carinae with small, equally spaced, elevated granules. Sternite: III possesses a triangular, median posterior area, which is smooth, shiny, and lacks pigmentation. Sternite V has two poorly defined, almost smooth, paramedian carinae, and two slightly defined median carinae which surround a median furrow. Sternum bears a very deep furrow. Pectines ( Fig. 2 e): with well defined fulcra and lamellae. Pectinal teeth (left/right): 21/21. Metasoma ( Fig. 3 a and 3b): dorsal carinae with granules increasing in size towards the distal segments (less defined than females); the distal granule is more elevated in segments III and IV. The remaining carinae are formed by small granules. Ventral carinae ( Fig. 3 a) double and parallel in segment I. In segment II are double and parallel in its entire length, poorly defined in the distal third which includes a vestigial internal (central) carinae. In segments III and IV carinae are double and parallel in the proximal third and unique in the rest of the segments. Segment V possesses five carinae; granules of dorsal carinae are very small and of larger size in the remaining carinae. There are granules of variable size at the sides of the segment. Telson ( Fig. 3 c): dorsal surface smooth, with well spaced granules of variable size. There is a line of poorly defined granules on the ventral surface.

Color ( Fig. 1 a). Live specimens basically yellowish to brown pale. Prosoma: posterior and lateral region of carapace brown. Ethanol-preserved specimens show a yellow-brown dorsal surface in metasome, pedipalps and legs. Carapace and tergites are deep brown, darker towards its distal half. Sternites deep brown. Pectines yellow.

Measurements (in mm). Length of carapace 9.61; width of carapace 9.90; length of right chela 31.07; width of the right chela 2.31; length of movable finger (right chela) 16.78; length of right patella 21.39; length of right femur 20.44; mesosome length 24.83; metasomal segments (width/length): I 4.31/9.03; II 3.96/11.12; III 4.14/11.97; IV 4.44/12.47; V 4.49/12.83; length of telson 12.05; length of right pecten 7.37; total body length 103.91.

(insert Figs. 2 and 3 around here)

Complementary details on the females of T. uquirensis . Based on CELT-877, an adult specimen collected by T. Gregoriani, G. Subero and L. De Sousa on 21/xi/2003, Las Melenas, in the western border of Paria Peninsula National Park, Mariño Municipality, Sucre State, Venezuela (between 23.00 and 24.00 hours, UV light, on the ground, Coffea arabica plantation). The following female characters complement the original description by González-Sponga (2001): Femur dorsal trichobothria d 3 to d 5 arranged on a straight line forming a right angle (90°) with d 1. Total length of right pedipalp: 44.19 mm. Total female body length: 93.07 (pedipalp represents 45.70% of the specimen´s total body length). Ratio width/length of the chela: 3.29 mm / 20.20 mm = 0.16. Ratio length of movable finger/length of chela: 12.95 mm / 20.20 mm = 0.64. Pectines: pectinal teeth (right/left): 20/20.

Measurements (in mm). Length of carapace 9.35; width of carapace 10.49; length of right chela 20.20; width of the right chela 3.29; length of movable finger (right chela) 12.95; length of right patella 12.24; length of right femur 11.75; mesosome length 30.34; metasomal segments (width/length): I 4.85/7.20; II 4.51/8.78; III 4.46/9.46; IV 4.67/10.46; V 4.85/10.98; length of telson 10.10; length of right pecten 5.55; total body length 93.07.

Variability. Number of pectinal teeth: frequency in males (n = 4, 8 pectens, right/left): 21/21 (2), 20/22 (1), and 20/20 (1). Frequency in females (n = 7, 14 pectens, right/left): 21/21 (1), 21/20 (2), 20/20 (3), and 19/ 18 (1). Number of denticles in movable finger (right chela): frequency in males (n = 4, 4 movable fingers): 18 (3) and 17 (1). Frequency in females (n = 7, 7 movable fingers): 18 (3) and 17 (4).

Small male (CELT-837) (measurements in mm): length of carapace 6.75; width of carapace 7.58; length of right chela 18.72; width of the right chela 1.81; length of movable finger (right chela) 10.89; length of right patella 12.84; length of right femur 11.85; mesosome length 18.85; metasomal segments (width/length): I 3.47/6.41; II 3.22/7.72; III 3.20/8.32; IV 3.61/8.63; V 3.55/9.02; length of telson 8.18; length of right pecten 5.77; total body length 73.88 (pedipalp represents 58.80% of the specimen´s total body length).

Seven juveniles, with body length between 43.75 and 61.71 mm, undefined developmental stage and sex, presented the following characteristics: dorsal tegument with an overall reticulated, pale yellow complexion. Ventral surface of mesosome and metasome and dorsal surface of metasome with similar pattern as above. Ventral surface of legs pale yellow. Pectines pale yellow. Subaculear tubercle spiniform, with two basal, elevated granules. Variations: (a) Number of pectinal teeth: Frequency (n = 7, 14 pectens, right/left): 20/20 (4), 20/21 (2), and 19/19 (1). Number of denticles in movable finger (right chela): frequency (n = 7, 7 movable fingers): 17 (6) and 13 (1). Morphometric data from the largest-sized juvenile specimen are presented (CELT- 955) (in mm): length of carapace 5.95; width of carapace 6.46; length of right chela 13.23; width of the right chela 2.01; length of movable finger (right chela) 9.04; length of right patella 7.71; length of right femur 6.90; mesosome length 19.34; metasomal segments (width/length): I 3.00/4.55; II 2.85/5.16; III 2.74/5.65; IV 2.75/ 6.52; V 2.78/7.43; length of telson 7.11; length of right pecten 3.88; total body length 61.71 (pedipalp represents 45.11% of the specimen´s total body length).

In three of the examined specimens, one of the following morphological alterations was observed: (1) right lateral eye with opacity (CELT-877), (2) right pecten with two pairs of pectinal teeth fused, (3) right movable finger with 13 oblique lines of denticles (CELT-955, juvenile).

Sexual dimorphism: males differ from females basically in the following characters: (1) in the length and shape of pedipalps: males have chelae slenderer and more elongated than females, (2) femur carinae are less conspicuous in males than females, (3) dorsal trichobothria d 3 to d 5 arranged on a straight line, forming an obtuse angle of approximately 152° with d 1 in males and 90° in females, (4) color: females darker and deep brown throughout.

Table 1 contains the measurements for the T. uquirensis specimens examined in this work (including medians and 95% confidence intervals). The results support the following conclusions: (1) the chela width is significantly larger in females, (2) the length of chela, patella, femur and right pecten are significantly larger in male specimens, (3) in males, the length of metasomal segments I to V, the length of the telson and the total body length are significantly larger than in females. In males the pedipalp length represents 66.80% of the total body length and 46.45% in the case of females.

Distribution and natural history. Up until now the geographical distribution of T. uquirensis was restricted to the type locality, around the village of Uquire, Arismendi Municipality ( González-Sponga 2001). Records gathered during this research allow us to extend its range up to the village of Las Melenas, Mariño Municipality, Paria Peninsula National Park, in the eastern section of the Coastal Venezuelan range ( Garrity et al. 2004: Digital shaded-relief map of Venezuela) ( Fig. 4 ). Las Melenas is located at a GPS (global positioning system) distance of 90 km southwest of Uquire and south of Humo Hill, the highest elevation of the Paria range. T. uquirensis inhabits evergreen transition and montane cloud forests ( Huber 1997), corresponding to the life zone “Bosque húmedo premontano (bh-P)” ( Ewel et al. 1968), where the predominant vegetation type are “bosques ombrófilos submontanos semideciduos estacionales” and “bosques ombrófilos montanos subsiempreverdes” ( Huber & Alarcón 1988). The predominant climate type in the area is rainy and warm (Koeppen Type A) (“Ami: bosque muy húmedo perennifolio transicional”, typical of forest areas under maritime influence) (annual average temperature, between 18 and 24°C; annual average precipitation 2 300 mm). The rainy season takes place between June and August and then between October and December. Dry months between February and April.

Anatomical Region ɗ Ψ p =

n = 3 n = 7

Median (mm) CI (95%) Median (mm) CI (95%) n: number of scorpions, p: level of statistical significance, ns: non-significant, Relation (%) = ratio length of pedipalp to total body length.

Some T. uquirensis specimens (CELT-877, 878, 951, 956) were found under decomposing vegetation and in trail crevices in cocoa ( Theobroma cacao ) and coffee ( Coffea arabica ) plantations. The species is sympatric with T. irapaensis González-Sponga, 2002 and possibly T. cachipalensis González-Sponga, 2002 . Some others were collected in human dwellings: a specimen was found in the bedroom area with one offspring still on top (CELT-997) and others in the house external wall (CELT-1004) or their surroundings (CELT-837, 998).

Figures

FIGURE 1. Tityus uquirensis (male specimen, CELT- 508). Dorsal view. Scale = 1 cm.

FIGURE 2. Tityus uquirensis, male. a. Carapace. b. Chelicerae. c. Right pedipalp, dorsal view. d. Right chela, lateral external view. e. Pectens. Scale: a, b and e = 1 mm; c and d = 5 mm.

FIGURE 3. Tityus uquirensis, male. a. Metasome, ventral view. b. Metasome, lateral view. c. Telson, lateral view. Scale: a and b = 5 mm; c = 1 mm.

FIGURE 4. Distribution of Venezuelan Tityus species with elongated pedipalps. Inset shows location of the Northeastern and Andean Regions in Venezuela. Northeastern Region: 1, T. uquirensis [Paria Peninsula National Park, Municipalities of Arismendi and Mariño (also possibly including Valdez Municipality), Sucre State; a = Type Locality, b = new record]. 2, T. quirogae (Caripe Municipality, Monagas State). 3, T. quirogae (Montes Municipality, Sucre State). Andean Region: 4, T. meridanus (Rangel Municipality, Mérida State). 5, T. nematochirus (Mérida Andes piedmont, Táchira and Barinas States). 6, T. surmeridensis (Padre Noguera Municipality, Mérida State).

Tables

TABLE 1. Median and 95 % confidence intervals (CI) for the morphometric data obtained from Tityus uquirensis male and female exemplars.

Length of carapace	9.06	8.51–9.42 8.40	8.14–8.72 ns
Width of carapace	9.28	8.65–9.68 9.35	9.07–9.77 ns
Length of right chela	27.53	25.62–29.30 19.05	18.17–19.68 0.05706
Width of right chela	2.16	2.04–2.24 3.11	3.02–3.20 0.05706