Genetic analysis evidence of population substructure within the endangered Irrawaddy dolphin (Orcaella brevirostris Gray, 1866) in Thailand and Indonesia

Authors

  • Trifan Budi Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, Bangkok 10900, Thailand. Interdisciplinary Graduate Program in Bioscience, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
  • Worata Klinsawat Conservation Ecology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkok 10150, Thailand
  • Janjira Phavaphutanon Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand
  • Sanit Piyapattanakorn Center of Excellence for Marine Biotechnology, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
  • Danielle Kreb Yayasan Konservasi RASI/Laboratory of Hydro-Oceanography, Faculty of Fisheries, Mulawarman University, Samarinda 75124, Indonesia
  • Pramana Yuda Fakultas Teknobiologi, Universitas Atma Jaya Yogyakarta, Yogyakarta 55281, Indonesia

Keywords:

Genetic connectivity, Genetic diversity, Irrawaddy dolphin, Panmixia, Population structure

Abstract

Importance of the work: The decline in numbers of the Irrawaddy dolphin threatens its viability. Genetic data scarcity imperils management decisions.
Objectives: To apply microsatellite-based analysis to assess the genetic diversity and population structure of the Irrawaddy dolphin in Thailand and Indonesia.
Materials & Methods: Skin and muscle samples were collected from stranded Irrawaddy dolphins in coastal and riverine areas of Thailand (n = 64) and Indonesia (n = 10). Individual DNA was analyzed using 12 microsatellite primers. However, DNA from only 15 individuals from Thailand and five from Indonesia could be successfully amplified. The data obtained were then used to assess population genetic parameters and population structure.
Results: A high level of genetic diversity was observed among Irrawaddy dolphin populations in Thailand and Indonesia. In total, 106 alleles were identified across four populations in Thailand and Indonesia, with mean observed heterozygosity (Ho) of 0.625 ± 0.048 and an allelic richness of 4.125 ± 0.182. Pairwise population differentiation and discriminant analysis of principal components supported significant population heterogeneity. These findings suggested a population structure within Irrawaddy dolphins across Thailand and Indonesia, contradicting the common assumption of panmixia in marine mammal populations.
Main finding: Genotyping data revealed a population substructure within Irrawaddy dolphin populations in Thailand and Indonesia, highlighting potential challenges for their long-term conservation.

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Published

2024-06-28

How to Cite

Budi, Trifan, Worata Klinsawat, Janjira Phavaphutanon, Sanit Piyapattanakorn, Danielle Kreb, and Pramana Yuda. 2024. “Genetic Analysis Evidence of Population Substructure Within the Endangered Irrawaddy Dolphin (Orcaella Brevirostris Gray, 1866) in Thailand and Indonesia”. Agriculture and Natural Resources 58 (3). Bangkok, Thailand:331–338. https://li01.tci-thaijo.org/index.php/anres/article/view/263797.

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Section

Research Article