Xenopholis werdingorum, Jansen, Martin, Álvarez, Lucindo Gonzales & Köhler, Gunther, 2009

Jansen, Martin, Álvarez, Lucindo Gonzales & Köhler, Gunther, 2009, Description of a new species of Xenopholis (Serpentes: Colubridae) from the Cerrado of Bolivia, with comments on Xenopholis scalaris in Bolivia, Zootaxa 2222, pp. 31-45 : 33-41

Xenopholis werdingorum sp. nov.

( Figs. 2–5 )

Holotype: MNKR 4700, adult female; Hacienda San Sebastián (S 16°21.676’, W 62°00.017’, 550 m; Fig. 6 ), Province of Ñuflo de Chávez, Department of Santa Cruz, Bolivia; collected about 2300 hours on 25 October 2006 by M. Jansen and A. Schulze.

Paratypes: ZSM 5113/2005, adult female; old cattle post San Ignacio near San José de Chiquitos (“…verlassene Ranchogruppe San Ignacio…,”, Krieg 1931:71), Province of Chiquitos, Department of Santa Cruz, Bolivia; collected by the German Chaco Expedition, which was between 20 and 28 September 1926 in that area according to the narration of the expedition by Krieg (1931); MNKR 4701, adult female, same locality data as holotype, collected about 2055 hours on 3 December 2008 by A. Schulze.

Etymology: The name werdingorum is a noun in the genitive case, proposed to honor the family Werding, owners of type locality Hacienda San Sebastián. Lutz Werding provided great hospitality and encouragement for our inventories of the flora and fauna on their property. Furthermore, the family Werding generously provided broad logistic and financial support for the building of a biological research station (Centro de Investigaciónes Ecológicas Chiquitos) on their grounds.

Diagnosis: The new species can be identified as a member of the genus Xenopholis by its characteristic vertebral morphology (see Boulenger (1896): Externally, the new species differs from all other species of Xenopholis and all members of Clelia by having a unique dorsal color pattern (dorsal and dorsolateral surfaces of head and body dark brown with an iridescent sheen, grading to yellowish orange laterally and onto venter). The new species can be distinguished from all other species of Xenopholis and all members of Clelia by the following combination of characters: (1) 19-19-17 dorsal scale rows; (2) 171–179 ventrals (mean 176, n = 3); (3) 38–40 subcaudals (mean 39, n = 3); (4) no apical pits on dorsal scales; (5) two to three supralabials in contact with the eye; (6) eye diameter 0.35 times the distance between the eye and the tip of the snout; (7) one anterior and two posterior temporals; (8) two prefrontals; (9) a narrow septum within the neural spine and perpendicular to its long axis, as seen in x-ray images ( Fig. 7 ).

Xenopholis werdingorum differs from X. scalaris (features of X. scalaris in parentheses) in color pattern (dirty brick red above, narrow black spots on the sides; Fig. 8 ); number of prefrontals (one prefrontal); shape of loreal (loreal as long as wide or only slightly longer); number of supralabials in contact with the eye (two); number of ventrals (127–146); dorsal scale rows at midbody (17-17-17); number of subcaudals (28–36); and vertebral morphology (no narrow septum within the neural spine visible in x-ray images, Fig. 7 ).

From X. undulatus , the new species is distinguished (features of X. undulatus in parentheses) in body color pattern (dorsal ground color yellowish, with a brown or black undulating band and lateral series of black spots; Fig. 9 ); coloration of head (dark streak behind the eye present; upper lip yellowish); and number of supralabials entering the eye (usually two, rarely three).

From the superficially similar species of the genus Clelia ( C. bicolor , C. clelia , C. equatoriana , C. errabunda , C. hussami , C. langeri , C. montana , C. plumbea , C. rustica , C. scytalina , and C. quimi ) the new species of Xenopholis differs (characters of Clelia in parentheses) by number of subcaudals (more than 43 in all species of Clelia ); number of ventrals in females (more than 192, except C. bicolor ); supralabials in contact with the eye (two); anterior temporals (usually two, rarely one in C. rustica and C. bicolor ; Fig. 10 ); and eye diameter (0.5 times the distance between the eye and the tip of the snout).

Description of holotype: Adult female ( Figs. 2–4 ), preserved in 70 % alcohol. Head little wider than neck; body long and diameter equal in all extensions; tail short relative to body, with conical tip; iris black and pupil round; nostril at anterior part of nasal scale; maxillary teeth aproximately 12, the last two grooved and separated from the others by a large diastema.

Measurements: SVL 338 mm; TL 52 mm; TTL 390 mm; head length 13.9 mm; height of head at level of parietals 4.9 mm; height of head at level of nostrils 3.0 mm; largest width at level of parietals 7.9 mm; width at level of nostrils 3.6 mm; diameter of orbit 1.6 mm, approximately 0.35 times the distance from eye to snout; diameter of body at level of neck 6.2 mm; diameter of body at level of midbody 10.0 mm; diameter of body one head length before cloaca 6.4 mm; diameter of base of tail 5.3 mm; diameter of middle of tail 4.0 mm; diameter of final part at level of last middorsocaudal scale 1.5 mm; length of conical tip of tail 1.8 mm; length of ultimate dorsal 0.9 mm; length of ultimate subcaudal 0.8 mm; proportions: TL/SVL: 0.15; head length/total length 0.36.

Pholidosis: Rostral wider than high; portion of tip of rostral visible from above less than length of suture between internasals; internasals wider than long (right internasal: width 1.8 mm, length 1.4 mm); prefrontals about as long as wide (right prefrontal: width 2.3 mm, length 2.2 mm); supraocular small (width 0.9 mm, length 1.3 mm); frontal irregularly heptagonal (width 3.7 mm, length 3.5 mm); nasal scales long (length 2.5 mm), in contact with loreal; preoculars 1/1, (right preocular: height 1.7 mm, length 1.2 mm); one loreal; 2/2 postoculars, lower postocular pentagonal and smaller than upper; supralabials 8/8; third to fifth supralabials in contact with eye; first supralabial triangular and smaller than others, third supralabial elongated posterodorsally at tip and reaching to eye; fourth supralabial below eye, fifth below eye and lower postocular; sixth and seventh supralabial below anterior temporal; sixth largest, irregular pentagonal; 1/1 anterior and 2/2 posterior temporals; anterior temporal narrow and long (right anterior temporal: height 1.4 mm, length 2.9 mm); upper and lower posterior temporals about same size (right lower posterior temporal: height 1.1 mm, length 2.0 mm; right upper posterior temporal: height 1.2 mm, length 1.7 mm); mental triangular (width 1.8 mm, length 1.4 mm); infralabials 9/9; first four infralabials in contact with anterior chin shields; fourth and fifth infralabials in contact with posterior chin shields; ninth infralabial smallest, fifth infralabial largest; anterior chin shields longer than posterior chin shields; anterior chin shields wider anteriorly than posteriorly; seven gular scales; one preventral; 178 ventrals; cloacal scute entire; 38 subcaudals; subcaudals/ventrals 0.21; dorsal scales smooth, in 19-19-17 rows, without apical pits; 12 dorsal scale rows at base of tail, eight at middle, and three before terminal scale.

Color in life: Dorsal and dorsolateral surfaces of head and body dark brown with an iridescent sheen, grading to yellowish orange laterally and onto venter, scales of pale lateral region with dark edges; throat and venter creamy white; supralabials creamy white to pale yellow, except upper tips of supralabials below eye and posterior to eye, which are the same color as dorsal portion of head.

Color in alcohol: Very similar as described for specimen in life, except that lateral brownish orange and orange-yellow portions have faded to creamy white.

Variation: The paratypes are very similar in scalation and pholidosis to the holotype (see Table 1 ). ZSM 5113/2005 (adult female; SVL 353mm; TL 58mm): 179 ventrals and 40 subcaudals; fourth to fifth supralabials contact eye; posterior upper edge of third supralabial elongated, reaching eye on both sides; only right parietal in contact with sixth supralabial, maxillary teeth aproximately 11. MNKR 4701 (adult female; SVL 312mm; TL 55mm): 171 ventrals and 40 subcaudals; 8 supralabials (3rd to 5th in contact with the eye); left and right parietals in contact with sixth supralabial.

length; TL: Tail length.

Coloration of paratypes in alcohol very similar to that of holotype: uniform dorsal and dorsolateral coloration on head and body (chocolate brown in ZSM 5113/2005, dark chocolate brown in MNKR 4701); in ZSM 5113/2005 dorsal coloration bordered by a longitudinal line of scattered, similarly dark dots, extending to level of cloaca ( Fig. 5 ).

Distribution and natural history: The new species is known only from the type locality and from close to San José, Department of Santa Cruz ( Fig. 6 ). Photographs and descriptions of specimens reported by Strüssman and Sazima (1993) and Marques et al. (2005) suggest this taxon might also be distributed in the Pantanal (see Strüssmann and Sazima 1993; Marques et al. 2005). Its occurrence in other neighboring open areas is possible, such as the savanna and Cerrado habitats of the Beni in Bolivia.

The holotype was active on the ground at 2300 hours in Cerrado savanna used for extensive cattle farming. The paratype MNKR 4701 was found at about 2100 hours at the edge of a wetland. Upon being captured, it was calm, exhibiting no aggressive behavior, but produced a strong-smelling secretion from the cloacal glands (A. Schulze, pers. comm.).

The x-ray image of the paratype ZSM 5113/2005 showed a frog in the stomach. The preference of anurans as prey for snakes of the genus Xenopholis was mentioned by Cunha and Nascimento (1978), Cunha et al. (1985), Duellman (1990), and França and Araújo (2007).

Figures

FIGURE 2. Holotype of Xenopholis werdingorum (MNKR 4700). Photo: A. Schulze.

FIGURE 3. Portrait of head of holotype of Xenopholis werdingorum (MNKR 4700). Photo: M. Jansen.

FIGURE 4. Head (lateral view) of holotype of Xenopholis werdingorum (MNKR 4700). Scale 10 mm.

FIGURE 5. Paratype (ZSM 5113 / 2005) of Xenopholis werdingorum. a) dorsal view; b) lateral view of midbody. Photo: M. Jansen.

FIGURE 6. Map showing localities of Xenopholis in Bolivia and adjacent areas. Xenopholis scalaris (squares), X. undulatus (circles), and X. werdingorum (triangles). Open symbols represent type localities. Question marks: doubtful records of X. scalaris given by Boulenger (1896) and Peters and Orejas-Miranda (1970 b) in Bolivia, and probable occurrence of X. werdingorum in the Pantanal of Brazil (see text for details). Additional distribution data taken from Amaral (1923, 1926), Bernarde and Abe (2006), Cadle et al. (2003), Cunha et al. (1985), Harvey et al. (1998), Jensen (1901), Lehr (2002), Loebmann (2009), Pérez-Santos and Moreno (1988, 1991), Schenkel (1902), Strüssman and Sazima (1993), and Wucherer (1862).

FIGURE 7. X-ray image of vertebrae of a.) Clelia bicolor (SMF 86639), b.) Xenopholis scalaris (SMF 88380), c.) X. undulatus (ZSM 5114 / 2005), d.) X. werdingorum (ZSM 5113 / 2005, paratype), and e.) X. werdingorum (MNKR 4700, holotype). ns = neural spine; sep = septum; see text for details. Photos: J. Habersetzer.

FIGURE 8. Juvenile of Xenopholis scalaris (SMF 88380), Arútam, Ecuador. Photo: G. Köhler.

FIGURE 9. Xenopholis undulatus (NMB 1865, type of Paroxyrhopus reticularis Schenkel). a) lateral view of midbody; b) dorsal view. Photo: M. Jansen.

FIGURE 10. Head (lateral view) of Clelia bicolor (MNKR 4703), Hacienda El Espinal, Department of Santa Cruz, Bolivia.

Tables

TABLE 1. Comparative morphometric and meristic data of Xenopholis species. See text for data sources. TTL: Total

Species	Distribution	Body size (mm)	Ventrals	Sub- caudals	Dorsal scale rows	Supralabials (eye contact)	Infra- labials	Temporals	Pre- frontals
Xenopholis scalaris	Ecuador, Columbia, Peru, Brasil, Bolivia	TTL 250 390; TL 40 55	127 144	28 35	17-17-17	8 (4 5), rarely 7 (3 4)	9	1+2	1
X. undulatus	Brazil, Paraguay	TTL up to 465; TL up to 70	166 181	39 42	19-19-17	8 (4 5, rarely 3 5 or 3 4)	9	1+2	2
X. werdingorum	Bolivia	TTL 367– 411; TL 55– 58	171 179	38 40	19-19-17	8 (3 5), rarely (4 5)	9	1+2	2