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Understanding dietary differences in Indian dugongs through opportunistic gut sampling of stranded individuals


Affiliations
1 Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
2 Wildlife Institute of India, Chandrabani, Dehradun 248 001, India; 2Marine Programme, Wildlife Conservation Society – India, Bengaluru 560 097, India, India
3 Wildlife Institute of India, Chandrabani, Dehradun 248 001, India; Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Puducherry 605 014, India, India
 

We analysed gut samples of stranded dugongs from Tamil Nadu and Gujarat, India, to understand their die­tary preferences. We quantified seagrass fragments from the gut as leaf, stem and rhizome, and identified leaf fragments up to genera level by their morphological features and epidermal cell characteristics using an in­verted microscope. The overall abundance of above-ground fragments (leaf, stem) was higher in all samples, which may suggest the dugongs use a cropping mechanism to forage. The ingested seagrass generic diversity was higher in Tamil Nadu (n = 5) dugong individuals than those in Gujarat (n = 2). A total of five genera were recorded from all samples, viz. Halophila spp., Halodule spp., Cymodocea spp., Enhalus sp. and Syringodium spp. In Tamil Nadu, Cymodocea spp. (46.24%) was the most dominant, followed by Halophila spp. (26.49%), Syringodium spp. (14.83%) and Halodule spp. (12.16%), with a low occurrence of Enhalus spp. (0.19%). In Gujarat, Halodule spp. (61.48%) was the most dominant, followed by Halophila spp. (30.20%). The recorded plastic and wood fragments suggest fine spatial scale threat mapping in dugong habitats

Keywords

Dugongs, foraging pattern, megaherbivore, necropsy, seagrass.
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  • Understanding dietary differences in Indian dugongs through opportunistic gut sampling of stranded individuals

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Authors

Sumit Prajapati
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
Chinmaya Ghanekar
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
Sameeha Pathan
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
Rukmini Shekar
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
K. Madhu Magesh
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
Swapnali Gole
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
Srabani Bose
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
Sweta Iyer
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India
Anant Pande
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India; 2Marine Programme, Wildlife Conservation Society – India, Bengaluru 560 097, India, India
Kuppusamy Sivakumar
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India; Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Puducherry 605 014, India, India
Jeyaraj Antony Johnson
Wildlife Institute of India, Chandrabani, Dehradun 248 001, India, India

Abstract


We analysed gut samples of stranded dugongs from Tamil Nadu and Gujarat, India, to understand their die­tary preferences. We quantified seagrass fragments from the gut as leaf, stem and rhizome, and identified leaf fragments up to genera level by their morphological features and epidermal cell characteristics using an in­verted microscope. The overall abundance of above-ground fragments (leaf, stem) was higher in all samples, which may suggest the dugongs use a cropping mechanism to forage. The ingested seagrass generic diversity was higher in Tamil Nadu (n = 5) dugong individuals than those in Gujarat (n = 2). A total of five genera were recorded from all samples, viz. Halophila spp., Halodule spp., Cymodocea spp., Enhalus sp. and Syringodium spp. In Tamil Nadu, Cymodocea spp. (46.24%) was the most dominant, followed by Halophila spp. (26.49%), Syringodium spp. (14.83%) and Halodule spp. (12.16%), with a low occurrence of Enhalus spp. (0.19%). In Gujarat, Halodule spp. (61.48%) was the most dominant, followed by Halophila spp. (30.20%). The recorded plastic and wood fragments suggest fine spatial scale threat mapping in dugong habitats

Keywords


Dugongs, foraging pattern, megaherbivore, necropsy, seagrass.

References





DOI: https://doi.org/10.18520/cs%2Fv123%2Fi10%2F1259-1264