Dipsas peruana (Boettger, 1898)

Arteaga, Alejandro, Salazar-Valenzuela, David, Mebert, Konrad, Penafiel, Nicolas, Aguiar, Gabriela, Sa ́ nchez-Nivicela, Juan C., Pyron, R. Alexander, Colston, Timothy J., Cisneros-Heredia, Diego F., Yanez-Munoz, Mario H., Venegas, Pablo J., Guayasamin, Juan M. & Torres-Carvajal, Omar, 2018, Systematics of South American snail-eating snakes (Serpentes, Dipsadini), with the description of five new species from Ecuador and Peru, ZooKeys 766, pp. 79-147 : 100-101

Dipsas peruana (Boettger, 1898)

Leptognathus peruana Boettger, 1898: 128. Holotype SMF 20801, a female from Santa Ana, department of Cuzco, Peru.

Leptognathus boettgeri Werner, 1901: 11. Holotype MTKD D 1671 M, a female from Chanchamayo, department of Junín, Peru.

Leptognathus boliviana Werner, 1909: 240. Holotype ZMH, a female from department of Beni, Bolivia.

Leptognathus polylepis Boulenger, 1912: 422. Holotype BMNH 1946.1.2078, a female from Huancabamba, department of Pasco, Peru.

Proposed standard English name.

Peruvian Snail-Eater

Proposed standard Spanish name.

Caracolera Peruana

Diagnosis.

Dipsas peruana differs from all described species of Dipsas based on the following combination of characters: (1) 15/15/15 smooth dorsals with moderately enlarged vertebral row; (2) one loreal and one preocular in contact with orbit; (3) 8-9 supralabials with 4-6 or 3-5 contacting orbit; (4) one pair of infralabials in contact behind symphysial; (5) 177-200 ventrals in males, 180-203 in females; (6) 75-127 divided subcaudals in males, 79-105 in females; (7) dorsal and ventral ground color brown to dark brown (light brown in juveniles) with 33-43 blackish brown to complete black, white to cream edged circular to vertically elliptical blotches that are longer than interspaces; head dark brown with dingy cream reticulations and different degrees of whitish edging on the labial scales, and a thin (1-3 scales long) white to light grayish brown irregular nuchal collar; dorsal blotches extending marginally onto ventrals and rarely fusing midventrally; (8) 199 mm SVL in males, 610-725 mm in females; (9) 85 mm TL in males, 155-241 mm in females.

Comparisons.

Dipsas peruana sensu stricto is compared to species previously subsumed under D. peruana sensu lato: D. latifrontalis , D. palmeri , and D. klebbai . From D. latifrontalis and D. palmeri , it differs in having dorsal blotches along the entire body similar in length or longer than interspaces (shorter than interspaces in D. latifrontalis and D. palmeri ), and in having melanized interspaces in some adult individuals. With the exception of BMNH 1946.1.2078, specimens of D. peruana can be separated from specimens of D. klebbai by possessing at least one of the following characteristics: posterior body blotches similar in length or marginally longer than interspaces (twice to four times as long in D. klebbai ); short circular to vertically elliptical body blotches usually only up to 4-7 vertebral scales long; melanized interspaces; dorsal surface of the head not completely black; and dorsal body blotches rarely fused ventrally.

Distribution.

Eastern slopes of the Peruvian and Bolivian Andes south of the Huancabamba depression at elevations between 1279 and 2671 m (Fig. 4).