Mitochondrial phylogeography reveals high diversity and unique divergent lineage in Indian Dugongs (Dugong dugon)

Abstract

1) India plays a central role in dugong conservation by hosting the largest population within south Asia. Current knowledge on status of Indian dugongs is limited due to paucity of reliable ecological data. This study generates mitochondrial control region sequences from about 10% of dugong population from major dugong populations within India. These data was compared with the global data to assess genetic lineages, population structure and genetic diversity of Indian populations.2) Multiple analyses suggest that the Indian dugong populations are part of a single genetic cluster, comprising south Asia, northwest Indian ocean and southwest Indian ocean populations. Despite small population size, they retain high genetic diversity with unique mitochondrial DNA haplotypes within south Asia.3) Within India, novel haplotypes were observed from all sampling sites with overall high haplotype diversity (0.85±0.04) but low nucleotide diversity (0.005±0.001). Indian populations exhibit high genetic differentiation with higher within-population variance (63.41%) than among populations (36.59%), signaling population structure. Few haplotypes were shared with Sri Lanka and southeast Asian populations, indicating potential genetic connectivity. 4)Being the most genetically unique population within south Asia, Indian dugong populations are globally significant. We recommend that Indian Dugong populations should be managed as a Conservation Unit to ensure population recovery and long-term survival of the species.

Spatio-temporal analysis identifies hotspots of marine mammal strandings along the Indian coastline: implications for developing a National Marine Mammal Stranding Response and Management policy

“…Further, over 8% stranded individuals could not be identified till species level with several misidentifications in the dataset. High dugong strandings have been reported through focused surveys (Sivakumar and Nair 2013) and formation of volunteer networks (Hatkar et al 2020;Srinivas et al 2020) but these records come from isolated pockets of dugong distribution along the Indian coast. This absence of quality information collection on stranding events arises due to lack of appropriate facilities and trained manpower to report strandings and conduct necropsies throughout the Indian coastline.…”