Population Genetic Structure of Silver Croakers, Pennahia argentata (Houttuyn, 1782), in the Gulf of Thailand Based on Cytochrome Oxidase Subunit I Gene Sequences

Genetic information is crucial to manage fish resources, and a good case in point is the population of silver croakers, Pennahia argentata (Houttuyn, 1782), which is economically important for Thailand. In the present study, 102 silver croaker samples were collected along the coast of the Gulf of Thailand and analysed for genetic variation based on nucleotide sequences in the cytochrome oxidase subunit I gene (510 bp). Of these, 33 haplotypes were examined, and 21 were singleton haplotypes, indicating a historical pattern of large female effective population sizes (female reproductive success). An analysis of molecular variance (AMOVA) and pairwise FST analysis showed that the geographic barrier did not affect the genetic structure of the silver croakers in the Gulf of Thailand. The minimum spanning network and phylogenetic tree revealed that the silver croaker population in the Gulf of Thailand separated into two haplogroups. Various methods to examine demographic history showed that the silver croaker population in the Gulf of Thailand had expanded. This study’s findings can guide the management of silver croaker populations in the Gulf of Thailand to conserve genetic diversity.