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

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.

Comparison of methods to estimate the size of Indian pangolin (Manis crassicaudata) scale seizures using species-specific conversion parameters

“…Accordingly, the cumulative sample weighed 2.032 kg. All scales in the sample were sorted into the three morph-types (i.e., broad rhombic/scapula shaped, elongated kite-shaped, and folded scales) as described in Algewatta et al (2021). The number of scales belonging to each morph-type was recorded.…”

“…1). Such detailed morphological characteristics have been described for Indian pangolin (Manis crassicaudata) by Algewatta et al (2021).…”

“…It is further estimated that the scales account for about 30-35% of the total body weight of Indian pangolin (Mohapatra et al 2015). Morphologically unique scale types can be observed in Indian pangolins Algewatta et al 2021). The scales differ in terms of the presence of grooves, size, and angle of the scales (Fig.…”

“…According to recent studies, there is intra-specific variation in the total number of scales of Indian pangolins, ranging from 440 to 530 (Ullmann et al 2019;Algewatta et al 2021;Perera et al 2021), though these disparities are likely due to different scale counting protocols adopted in various studies . It is further estimated that the scales account for about 30-35% of the total body weight of Indian pangolin (Mohapatra et al 2015).…”

“…Indian pangolin is the only pangolin species recorded in Sri Lanka (Mahmood et al 2019;Algewatta et al 2021). There are no records to suggest that Sri Lanka is used as a transit point in the IWT of pangolin scales (Perera et al 2017;.…”