Phylogeography of Dugong: Molecular Insights from Indian Subcontinent

Dugong (Dugong dugon) is the only existing herbivorous marine mammal of the order Sirenia which inhabits nearshore Indian waters. Interviews with fishermen have estimated its number to have declined to less than 200... [ view full abstract ]

Dugong (Dugong dugon) is the only existing herbivorous marine mammal of the order Sirenia which inhabits nearshore Indian waters. Interviews with fishermen have estimated its number to have declined to less than 200 individuals and hence regional assessment considers its population to be endangered in the Indian sub-continent. Despite its endangered status and continually degrading habitat, limited studies within the country deal with all aspects of species conservation.

As part of the Dugong Recovery Program, current study aims to address gaps in Dugong conservation in India. Along with generating ecological data on the species, this study targets lacunae in genetic information on Dugong populations to identify Evolutionary Significant Units (if any) for planning conservation strategies for the species.

 In this study, we collected eleven samples across dugong range states. Phylogeographic analysis was carried out using Mitochondrial DNA control region (mtDNA CR) sequences. Analysis of 400-bps mtDNA CR sequences from India revealed four haplotypes with six polymorphic sites as well as three additional haplotypes in comparison to globally available dugong haplotypes. Median joining network analysis suggests that Indian samples along with Mauritius form a separate clade within Australian clade separating them from other south east Asian countries. None of the Indian haplotypes were shared with any other globally available haplotypes indicating that Indian population might have diverged from the main Australian clade and thus forms a sub-clade.

 Phylogeographic analysis highlighted the importance of Indian dugong population in the global perspective and future conservation strategies should consider and plan accordingly.