The dugong (Dugong dugon) is indigenous to the coastal waters of the Indo-Pacific Ocean and is vulnerable to extinction throughout its range due primarily to anthropogenic effects. In Thailand the population of dugongs is approximately 250 animals and is found in fragmented habitats along the Thai coast. Genetic studies were implemented in this study to assess regional genetic composition and determine if there is variation in the D-loop sequences or microsatellites consistent with philopatry to regions, by males or females, or indicating dispersal. Utilizing D-loop sequences, 27 haplotypes were found that grouped into three haplogroups that were not differentiated by region but did show spatial differentiation when analyzed with F-statistics. Microsatellite analysis provided evidence of three populations—one in the Gulf of Thailand and two in the Andaman Sea (north Andaman Sea and Trang Province). Weak structuring of mtDNA variation occurs between neighboring Andaman Sea regions and may indicate philopatry by females due to high quality seagrass meadows in Trang Province especially. Nuclear DNA analysis provided a signal of dispersal between the two sides of the peninsula explaining how genetic variation has remained at levels above expected for a species with declining numbers. Utilizing established bottleneck tests, no evidence was found indicating a bottleneck in the population, though there was a signal of population decline, especially in the Gulf region. Overall recommendations are for further molecular studies utilizing a greater sample size and additional populations in the Indo-Pacific region to determine historic dispersal and a more comprehensive study of population viability.
|Advisor:||Parr, Leslee A.|
|Commitee:||Hines, Ellen, Mackie, Joshua|
|School:||San Jose State University|
|School Location:||United States -- California|
|Source:||MAI 52/05M(E), Masters Abstracts International|
|Subjects:||Genetics, Conservation, Biological oceanography|
|Keywords:||Conservation genetics, Dugong, Marine mammal, Microsatellite, Mitochondria, Thailand|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be