ABSTRACT

Knowledge about DNA polymorphisms found in Fenneropenaeus merguiensis in Thailand may represent an important contribution to the study of the phylogeographic history of this widespread genus and provide important genetic information, which can be useful in the management of this resource. In this study, the genetic diversity and geographic differentiation of the banana prawn, F. merguiensis, in the Thai Peninsula region were examined using an intron polymorphism of the gene locus PvAmy. Our survey of 163 samples of F. merguiensis from five populations collected from the Gulf of Thailand (Trad, Surat Thani, and Songkhla) and the Andaman Sea (Satun and Trang) revealed a great and highly significant differentiation between the Gulf of Thailand and the Andaman Sea (FST = 0.324, P < 0.001). Significant population differentiation was also found within the Gulf of Thailand. These results were compared to those of a previous mitochondrial DNA survey spanning the same geographical range, and in which two divergent mitochondrial clades were reported. This study provides support for the hypothesis that the existence of these two clades is not due to a mixture of cryptic species but, rather, reflects their phylogeographic origin. The strong genetic structure of F. merguiensis on each side of the Thai Peninsula that was observed based on both mitochondrial and nuclear genes could, thus, be linked to the phylogeographic divide between the Indian Ocean and Pacific forms on the west and east sides of the Peninsula, respectively.