Microtityus bivicentorum, Botero-Trujillo, Ricardo, Erazo-Moreno, Martha C. & Pérez, Gustavo A., 2009

Botero-Trujillo, Ricardo, Erazo-Moreno, Martha C. & Pérez, Gustavo A., 2009, A new species of Microtityus Kjellesvig-Waering (Scorpiones: Buthidae) from northern Colombia, Zootaxa 2120, pp. 27-38 : 29-36

Microtityus bivicentorum sp. nov.

Figures 1–21 ; Table 1

Type series. — Holotype: COLOMBIA: Cesar Department: adult ♂ from Valledupar, Cerro Los Besotes, Santuario de Vida Silvestre Los Besotes, Camino Los Carretos, 10º34’25.0’’N 73º15’48.3’’W, 366 m elevation, Pitfall trap, 20 April 2008, M.C. Erazo-Moreno & G.A. Pérez coll. (MPUJ-SC0-380).

Paratype: COLOMBIA: Cesar Department: adult ♀ from Valledupar, Cerro Los Besotes, Santuario de Vida Silvestre Los Besotes, Manantial Los Zainos, 10°34’24.7’’N 73°16’26.0’’W, 200 m elevation, ad hoc, under stone, at night, 23 April 2008, G.A. Pérez coll. (MPUJ-SC0-381).

Distribution. —Known only from the type locality.

Etymology. —The species name is dedicated to Jose Vicente Rodríguez-Mahecha and Jose Vicente Rueda-Almonacid, formerly at "Conservación Internacional" in Bogotá. It is derived from the junction of the prefix "Bi" (meaning two or double) and the personal name "Vicente", a combination that takes advantage to celebrate the academic labor of both individuals.

Diagnosis. — Microtityus bivicentorum sp. nov. differs from all other species described in the genus by the following unique combination of features: pedipalps with reductive neobothriotaxy, with trichobothria d2 absent on femur and patella, and Eb3, Esb and esb absent on chela ( Figs. 12–17 ); trichobothrium et located between db and dt on pedipalp fixed finger ( Fig. 16 ); movable finger with 11–12 rows of granules; pectinal basal piece quadrangular in shape in both sexes, lacking posterior projection ( Figs. 8–9 ); sternite V of males with three smooth, hyaline areas, of which the median is shaped like an equilateral triangle, and the laterals are large and flattened ( Fig. 10 ).

Description of the male holotype.

Coloration. —Carapace predominantly yellow with abundant dark-brown mottling throughout. Median and lateral ocular tubercles blackish. Chelicerae yellow with some brownish areas located basally on both fixed and movable fingers; teeth reddish. Tergites predominantly yellow; I–VI with brown regions restricted to the posterior margin and separated from each other by the longitudinal carinae which are yellow, and with an anteromedian brownish region which is darker in tergites IV–VI; VII with brown-colored areas laterally and dorsoanteriorly. Coxosternal region, genital operculum, pectines, pectinal basal piece and sternites completely yellow and spotless. Metasoma predominantly yellow with some brown areas. Telson with vesicle, subaculear tubercle and basal half of aculeus immaculately yellow and spotless; distal half of aculeus dark-red. Pedipalps predominantly yellow, with brownish areas over dorsal, internal and external surfaces of femur and patella, and dorsal and external surfaces of chela; ventral surfaces of all segments and internal surface of chela completely yellow; fixed and movable fingers reddish brown, darker basally. Legs with variegated pigmentation in all segments, except for the telotarsi which are yellow.

Morphology. —Carapace: Subtriangular, densely granulose throughout; anterior margin deeply emarginated; median ocular tubercle slightly anterior to the centre of the carapace; lateral ocular tubercles each with three ocelli; anterior median, supercialiary, central median and posterior median carinae pronounced and elevated; lateral ocular carinae vestigial; anterior marginal, anterior median and median ocular furrows deep; posterior marginal, posterior median, lateral ocular, central lateral and central median furrows shallow; other carinae and furrows absent. Tergites: With similar granulation to that of the carapace; five longitudinal carinae (median; paired median lateral and lateral carinae) are present on the posterior half of tergites I–IV, the lateral carinae vestigial ( Fig. 6 ); tergites V–VI with evident median and median lateral carinae of similar development than in the preceding tergites, but lateral carinae apparently absent ( Fig. 6 ); TABLE 1. Meristic data for Microtityus bivicentorum sp. nov. Measurements in millimeters. 1Sum of prosoma, mesosoma and metasoma. 2Sum of tergites I–VII. 3 Sum of metasomal segments I–V and telson. 4Sum of femur, patella and chela. 5Measured from the commissure of the junction with the movable finger to the finger tip. 6Measured along the marginal lamella.

Male holotype Female paratype movable finger length: 1.44 2.00 palm length: 1.23 1.36 Pectines: length:6 0.86 0.90 teeth count (left/right): 9/9 8/8

tergite VII pentacarinate, with the median carina represented by an anteromedian elevation ( Fig. 6 ). Coxosternal region: Sternum pentagonal ( Fig. 8 ), depressed anteriorly; all the components of this region granulose, except for coxapophyses I–II which are smooth. Genital operculum and pectines: Genital operculum divided longitudinally, formed by subtriangular plates ( Fig. 8 ); pectines less than two thirds the length of coxae IV; pectinal marginal lamellae with 3/3 pieces, middle lamellae with 5/5, fulcra with 8/8; teeth count 9/9; pectinal basal piece almost quadrangular in shape, with anteromedian notch ( Fig. 8 ). Sternites: Densely granulose throughout; sternites VI–VII with paired submedian and lateral carinae, incomplete and granulose ( Fig. 7 ); sternite V with three posterior smooth, hyaline areas, of which the median one is shaped like an equilateral triangle, and the lateral ones are large and flattened ( Fig. 10 ); book lung spiracles short and oval. Metasoma: Segments I–II with ten carinae (paired ventrosubmedian, ventrolateral, median lateral, dorsolateral, and dorsosubmedian carinae), the median lateral less developed in segment II; segments III–IV with eight carinae (the median lateral absent); segment V with five carinae (ventromedian, paired ventrolateral and dorsolateral carinae); all carinae granulose; intercarinal spaces with abundant granulation. Telson completely smooth; subaculear tubercle strong, with two small dorsal granules; aculeus strongly curved ( Fig. 11 ). Chelicerae: Cheliceral dentition characteristic of the family Buthidae ( Vachon 1963) . Movable finger externally with two small basal teeth, one median pronounced tooth, one subdistal tooth slightly shorter than the median, and one distal tooth. Fixed finger externally with one basal and one median tooth mounted onto a bicuspid, one subdistal, and one distal tooth. Internal surfaces of both movable and fixed fingers are hidden by the coxapophyses and pedipalp trochanters, since the chelicerae are retracted deep under the carapace and could not be pulled out successfully; therefore, dentition on the internal surfaces is not observable. Pedipalps: Densely granulose throughout; femur with proximo-marginal carina, five longitudinal carinae (dorso-interior, dorso-exterior, ventro-exterior, ventro-interior carinae, plus an additional one on internal median position), and pronounced non-spinoid tubercle located basally on the internal surface; patella with eight longitudinal carinae [all of those identified by Stahnke (1970)], of which the ventro-median is vestigial) and two enlarged and spine-like granules on the dorso-interior carina and one on the ventro-interior; chela with nine longitudinal carinae; all carinae of all segments granulose. Movable and fixed fingers each with eleven slightly imbricate rows of granules in both pedipalps (including the short apical row) ( Figs. 18–19 ). Trichobothria: Trichobothriotaxy Type A ( Vachon 1974, 1975) with 34 trichobothria (reductive neobothriotaxy) ( Figs. 12–17 ): femur with ten trichobothria in α configuration (d2 absent) ( Figs. 12–13 ), patella with twelve (d2 absent) ( Figs. 14–15 ), and chela with twelve (Eb3, Esb and esb absent) ( Figs. 16–17 ). Legs: Tibia, basitarsus and telotarsus with abundant setation; tibial spur absent; prolateral and retrolateral pedal spurs present on all legs.

Female paratype and sexual dimorphism.

Similar to the male holotype, but the following differences were identified and are attributed to sexual dimorphism: lateral carinae on tergites I–VI markedly vestigial; 8/8 pectinal teeth; pectinal basal piece without anteromedian notch and longer than in the male ( Fig. 9 ); sternite V without posterior smooth, hyaline areas. Other differences were also detected, but cannot be reliably attributed to dimorphism: 7/7 pectinal fulcra; telson with few granules located dorsally on the posterolateral surfaces; movable finger of both pedipalps each with twelve rows of granules and fixed fingers with eleven rows. Cheliceral movable finger internally with two small teeth (one basal and one median) and one distal tooth; cheliceral fixed finger internally with only one small tooth.

Comparisons.

Microtityus bivicentorum sp. nov. is most similar to M. franckei , Microtityus desuzeae González-Sponga, 2001 [originally M. desuzei , corrected by Rojas-Runjaic & de Sousa (2007)] and Microtityus joseantonioi González-Sponga, 1981 , with which it shares the absence of trichobothrium d2 on femur, Eb3 and Esb on pedipalp chela, and esb on fixed finger, a combination unique to these species. The new species differs form M. franckei because in the former trichobothrium et is located between db and dt on pedipalp fixed finger ( Fig. 16 ), and sternite V of males exhibits three smooth, hyaline areas ( Fig. 10 ); in contrast, in M. franckei et is basal to db ( Fig. 22 ; Botero-Trujillo & Noriega 2008: fig. 13), and sternite V of males has only one smooth, hyaline area ( Botero-Trujillo & Noriega 2008: fig. 8). Also, the new species differs from M. franckei in the "palm to movable finger” ratio, approximately 4: 5 in the former but 3: 5 in the latter ( Figs. 20–23 ).

Microtityus bivicentorum sp. nov. differs from M. joseantonioi because in the former species patellar trichobothrium d2 is absent ( Fig. 14 ), the movable finger of pedipalp chela has 11–12 rows of granules, the pectinal basal piece is quadrangular in shape in both sexes (despite sexual dimorphism) ( Figs. 8–9 ), the median smooth, hyaline area on sternite V of males is shaped like an equilateral triangle, and the lateral areas are large and flattened ( Fig. 10 ); in contrast, in M. joseantonioi patellar trichobothrium d2 is present ( González-Sponga 1981: fig. 11), the movable finger of pedipalp chela has nine rows ( González-Sponga 1981), the pectinal basal piece is not quadrangular in either males or females [it is curved posteriorly in males and has a posterior projection in females ( González-Sponga 1981: figs. 15–16)], the median smooth, hyaline area on sternite V of males is higher than wide (shaped like an isosceles triangle), and the lateral areas are much reduced and ovoid ( González-Sponga 1981: fig. 14).

Finally, the new species differs from M. desuzeae on the basis of the patellar trichobothrium d2, absent in M. bivicentorum sp. nov. ( Fig. 14 ) but present in M. desuzeae ( González-Sponga 2001: figs. 7–8), and the number of granular rows on the pedipalp movable finger, 11–12 in the former species but nine in the latter ( González-Sponga 2001).

Figures

FIGURE 1. Known distribution of Microtityus bivicentorum sp. nov. (), Microtityus desuzeae (․), Microtityus franckei (˔) and Microtityus joseantonioi (●).

FIGURES 2 – 5. Microtityus bivicentorum sp. nov. 2 – 3. Male holotype, dorsal and ventral views. 4 – 5. Female paratype, dorsal and ventral views. Scale bars = 5 mm.

FIGURES 6 – 7. Microtityus bivicentorum sp. nov., male holotype under UV light. 6. Dorsal view. 7. Ventral view. MC = Median carina; MLC = Median lateral carina; LC = Lateral carina; SMC = Submedian carina. Scale bars = 5 mm.

FIGURES 8 – 11. Microtityus bivicentorum sp. nov. 8. Sternum, genital operculum, pectinal basal piece, and pectines of male holotype. 9. Sternum, genital operculum, pectinal basal piece, and pectines of female paratype. 10. Sternite V of male holotype. 11. Telson of male holotype, lateral view. Scale bars = 0.5 mm.

FIGURES 12 – 17. Microtityus bivicentorum sp. nov., distribution of the trichobothria in male holotype (illustrated from the right pedipalp). 12. Femur, dorsal view. 13. Femur, internal view. 14. Patella, dorsal view. 15. Patella, external view. 16. Chela, external view. 17. Chela, ventral view. Scale bars = 0.5 mm.

FIGURES 18 – 23. Right pedipalp chela. 18 – 21. Microtityus bivicentorum sp. nov., male holotype. 18. Detail of the movable finger dentition. 19. Detail of the fixed finger dentition. 20. Chela, external view. 21. Chela, ventral view. 22 – 23. Microtityus franckei, male paratype (MPUJ-SCO- 367). 22. Chela, external view. 23. Chela, ventral view. Scale bars = 0.5 mm.