Mitogenomes provide insight into complex evolutionary history of freshwater and coastal Irrawaddy dolphin (Orcaella brevirostris Gray, 1866) in Thailand and Indonesia

Authors

  • Trifan Budi Conservation Ecology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkok 10150, Thailand. Fakultas Teknobiologi, Universitas Atma Jaya Yogyakarta, Yogyakarta 55281, Indonesia
  • Sanit Piyapattanakorn Center of Excellence for Marine Biotechnology, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
  • Danielle Kreb Yayasan Konservasi Rare Aquatic Species of Indonesia, Samarinda 75124, Indonesia
  • Pramana Yuda Fakultas Teknobiologi, Universitas Atma Jaya Yogyakarta, Yogyakarta 55281, Indonesia
  • Santi Ninwat Marine and Coastal Resources Research Center, the Lower Andaman Sea, Department of Marine and Coastal Resources, Trang 92150, Thailand
  • Pornthipa Hardwises Marine and Coastal Resources Research Center, the Lower Gulf of Thailand, Department of Marine and Coastal Resources, Songkhla 90000, Thailand
  • Pimchanok Prachamkhai Marine and Coastal Resources Research Center, the Central Gulf of Thailand, Department of Marine and Coastal Resources, Chumphon 86000, Thailand
  • Wansuk Senanan Department of Aquatic Sciences, Faculty of Science, Burapha University, Chonburi 20131, Thailand
  • Surasak Thongsukdee Marine and Coastal Resources Research and Development Center, the Upper Gulf of Thailand, Department of Marine and Coastal Resources, Samut Sakhon 74000, Thailand
  • Janjira Phavaphutanon Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand
  • Worata Klinsawat Conservation Ecology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkok 10150, Thailand

Keywords:

Divergence time, Genetic connectivity, Genetic diversity, Irrawaddy dolphin, Pleistocene

Abstract

Importance of the work: Irrawaddy dolphins have experienced demographic decline. The lack of genetic information might hamper management decisions necessary for restoring population viability.
Objectives: To apply population genetics and mitogenome phylogenetic analyses to assess genetic diversity and connectivity among Irrawaddy dolphin populations in Indonesia and Thailand.
Materials & Methods: Samples from stranded dolphins were collected from Mahakam River and East Kalimantan, Indonesia and from Songkhla Lake and the Lower and Upper Gulf of Thailand. Based on Bayesian time-scaled phylogeny and pairwise population differentiation, the divergence times were estimated between Irrawaddy dolphin lineages and potential historical factors influencing the observed genetic structure were inferred.
Results: The Indonesian populations had lower mtDNA diversity compared to Thailand populations. Pairwise population differentiation and analysis of molecular variance based on the control region supported high differentiation among fragmented Thailand and Indonesian populations (FST = 0.6622, p < 0.0001) with 66.21% variation among groups, except for the Songkhla Lake and coastal Lower Gulf populations. Phylogenetic analyses revealed close relationships between some of the Thai and Indonesian haplotypes, suggesting historical freshwater connectivity. There was a lack of monophyly despite the strong support for the Mahakam River clade in Indonesia. The Mahakam River population started to diversify during the late Pleistocene (~304.4 Ka; 95% highest posterior density (HPD) = 157.8–505.3 Ka), possibly due to sea-level fluctuation and changes in palaeodrainage systems.
Main finding: The results of the genetic diversity and complex evolutionary history of the Irrawaddy dolphin raise conservation concerns and support management strategies aiming to restore population connectivity and reduce the impacts of genetic and demographic stochasticity.

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Published

2022-06-17

How to Cite

Budi, Trifan, Sanit Piyapattanakorn, Danielle Kreb, Pramana Yuda, Santi Ninwat, Pornthipa Hardwises, Pimchanok Prachamkhai, Wansuk Senanan, Surasak Thongsukdee, Janjira Phavaphutanon, and Worata Klinsawat. 2022. “Mitogenomes Provide Insight into Complex Evolutionary History of Freshwater and Coastal Irrawaddy Dolphin (Orcaella Brevirostris Gray, 1866) in Thailand and Indonesia”. Agriculture and Natural Resources 56 (3). Bangkok, Thailand:583-96. https://li01.tci-thaijo.org/index.php/anres/article/view/255075.

Issue

Vol. 56 No. 3 (2022): May-June

Section

Research Article

License

Copyright (c) 2022 Kasetsart University

online 2452-316X print 2468-1458/Copyright © 2022. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/),
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