Xenoxybelis boulengeri ( Procter, 1923 )

Rivas, Luis R., Rey-Ortíz, Gustavo, Eversole, Cord B., Powell, Randy L., Navarro-Cornejo, Gonzalo, Cortez, Edson, Ocampo, Mauricio, Callapa, Gabriel & Muñoz, Arturo, 2024, Vine snakes (Oxybelis) and Sharpnose snakes (Xenoxybelis) (Squamata, Serpentes) from lowlands of Bolivia, with first records of Oxybelis inkaterra for the country, Herpetozoa 37, pp. 201-211 : 201-211

Xenoxybelis boulengeri ( Procter, 1923)

Fig. 4 C, D

Specimens examined.

Two adult males ( CIRAH - 589, 608) collected at 2318 and 2112 h on 28 and 30 June 2017 from San Francisco community. Two adult males ( CIRAH - 624, 670) collected at 2122 and 0036 h on 01 and 04 July 2017 from Alta Gracia community. Two adult males ( CIRAH - 730, 744) collected at 2332 and 2229 h on 04 and 05 June 2019 from Vera Cruz community. One juvenile ( CIRAH - 1086) collected at 1943 h on 07 July 2023 from Ucia community (Table 3 , Fig. 5 ).

Morphometric and meristic characters.

Snout-vent length 615–728 mm (adults> 500 mm, n = 6). Tail length 340–506 mm (n = 6). Smooth dorsal scales 17-17 - 15 rows (100 %), without apical pits. Ventral scales 196–209 (x ̅ = 201). Subcaudal scales 163–187 (x ̅ = 180). Divided cloacal plate (100 %). Loreal 1 (100 %). Preoculars 1–2 (1 / 1 in 71 % of specimens, and 2 / 2 in 29 %). Postoculars 2–3 (2 / 2 in 57 % of specimens, and 3 / 3 in 43 %). Generally temporals 1 + 1 (2) + 2 and 1 + 2 + 3 or less. Supralabials 6–7 (6 / 6 in 86 % of specimens and 6 / 7 in 14 %); fourth contacting the orbit. Infralabials 7–8 (7 / 7 in 57 % of specimens, 7 / 8 in 29 % and 8 / 8 in 14 %); the first four contacting the first pair of chin shields (100 %) (Table 4 ) and fourth and fifth contact the second pair of chin shields (100 %).

Coloration pattern.

Upper center region of head brown; dorsolateral region of the head and supralabials yellowish green, separated by a dark brown band with black edges, from nasal, crosses the eye, and extends to the front of the body; ventral surface of the head yellowish green. Dorsal surface of the body with two thin dark greenish-brown lateral bands, the broad vertebral band light greenish-brown, the broad lateral bands light green (much brighter on the anterior part of the body); ventral surface uniform yellowish-green (Fig. 4 C, D ).

Ecological notes.

The specimens were found resting (coiled) on tree branches between 0.5–2 m above the ground, during nocturnal searches between 1943–0036 h. The localities where they were found correspond to primary and secondary Amazonian forests of the Manuripi and Tahuamanu river sub-basin.

Figures

Figure 4. Sharpnose snake from Bolivia. A, B. Dorsal and ventral view Xenoxybelis argenteus (MHNC-R 442), Villa Fatima community, Moxos, Beni; C, D. Dorsal (CIRAH - 670) and ventral (CIRAH - 624) view Xenoxybelis boulengeri, Alta Gracia community, Munuripi, Pando. Photos by Gabriel Callapa (A, B) and Cord Eversole (C, D).

Figure 5. Distribution of the sharpnose snakes in Bolivia. Xenoxybelis argenteus (squares), and Xenoxybelis boulengeri (diamond). Red symbols correspond to additional records.