No genetic divergence between green turtle Chelonia mydas nesting populations from the Andaman Sea and the Gulf of Thailand

Abstract

Nucleotide sequences from the control region of the mitochondrial (mt) DNA were analyzed for Thai green turtles (Chelonia mydas) to reveal population genetic structure. Four primers were employed i.e. Green15552F (GTGTC CACAC AAACT AACTA CCT), Green16300R (GTCTC GGATT TAGGG GTTTG GCG), Green15579F (CTGCC GTGCC CAACA GAACA), and Green16087R (CCAGT TTCAC TGAAT CGGCA). The aligned sequences contained 438 base pairs (bp) with 254 polymorphic sites. There were 8 haplotypes assigned from the 49 green turtles sampled from the Andaman Sea (19 individuals) and the Gulf of Thailand (30 individuals). Low genetic divergence between the nesting green turtle populations of the Gulf of Thailand and the Andaman Sea was detected in both haplotypic (Gst=0.00311) and nucleotide levels (Nst=0.02838) as well as genetic distance (DTN=0.016±0.003). Haplotype frequencies were not significantly different between the two nesting sites. The result was in contrast with a finding using satellite telemetry that discovered separated home ranges. Recent population separation and/or highly conservation of the studied mtDNA region might be an explanation.