Preliminary morphological record and analysis of the oriental rat snake (Ptyas mucosa) in Lakki Marwat, Pakistan

Abstract

This study confirmed the first morphological record of the Oriental Rat Snake (Ptyas mucosa), in Lakki Marwat District, Khyber Pakhtunkhwa (KPK), and Pakistan, expanding its known geographic range and contributing to regional herpetofaunal databases. In the current study, morphological identification of an adult male specimen collected in June 2025 was done, including detailed meristic counts (dorsal, ventral, and subcaudal scales) and morphometric measurements (snout-vent length, tail length, and cranial dimensions). The specimen was preserved in ethanol and examined using standardized taxonomic protocols. Key diagnostic traits were 17 midbody dorsal scale rows, 193 ventrals, 111 subcaudals, a divided anal plate, elongated tail (TlL/SVL ratio: 0.374), and robust cranial proportions (HL/SVL: 0.031). These features distinctly differentiate it from congeners, which exhibit fewer dorsal rows (15), lower subcaudal counts (74–80), and undivided anal plates. Additionally, the specimen’s larger body size (SVL: 976 mm) and unique scalation (8 upper/9 lower labials) suggest potential ecological adaptations or regional phenotypic divergence. The current study emphasize the need for integrating morphological data with molecular analyses to resolve taxonomic uncertainties and inform conservation strategies for colubrid snakes facing habitat degradation and illegal trade