Updates on the Morphometric Characterization of Indian Pangolin (Manis crassicaudata) in Sri Lanka

SIMPLE SUMMARY: The Indian pangolin (Manis crassicaudata) is one of the eight extant pangolin species in the world, listed as “endangered” by the International Union for Conservation of Nature (IUCN). The species is native to the Indian subcontinent. The Indian pangolin population in Sri Lanka is geographically isolated from the mainland population and therefore, could possess morphological adaptations to the unique environmental conditions in the island. However, an accurate description of the morphological features has not been attempted for Indian pangolins occurring on the island. This study described the morphological features of Indian pangolins based on observations made on 27 specimens from Sri Lanka. The adult male Indian pangolin measures between 137 and 177 cm from the snout to the tip of the tail and weighs between 20.4 and 48.8 kg. The largest Indian pangolin recorded so far from any of its range counties, weighing 48.76 kg and measuring 176.8 cm in total body length was recorded in this study. Indian pangolins recorded from Sri Lanka on average bear 511 ± 21 scales. Three major scale morph/types are further described. ABSTRACT: An accurate morphological description and analysis based on reliable data are unavailable for the geographically isolated population of M. crassicaudata in Sri Lanka. This study provides the most updated morphological description of M. crassicaudata with special reference to body measurements directly obtained from 27 specimens collected island-wide. Morphological parameters were recorded under three age classes that were defined based on their body weight (BW) and total body length (TBL); juvenile (BW: <4.3 kg TBL: <56.0 cm), subadult (BW: 4.3–7.3 kg TBL: 56–101 cm), and adult (BW: >7.3 kg TBL: >101 cm) and gender to reveal sexual dimorphism based on morphometric parameters. The TBL of adult males ranged between 137 and 177 cm while body weight ranged between 20.4 and 48.8 kg. The average count of body scales was 511 ± 21. The body scales were found arranged in 13 longitudinal rows with the highest number of scales observed on the vertebral scale row (16 ± 1). Three major scale morphs were identified; broad rhombic scales, elongated kite-shaped scales, and folded shaped scales. Broad rhombic shaped scales was the dominant scale type (80.49%) on the body (405 ± 7). The tail-length to body-length ratio of an Indian pangolin was 0.87. The tail length of an Indian pangolin is a reliable predictor of the TBL and has potential implications in quick field data gathering.