Genetic structure and diversity of the red big eye Priacanthus macracanthus in the northwestern Pacific Ocean

Abstract Understanding genetic diversity and population structure is essential for effective fisheries management. This study examined the population genetic structure, diversity, and demography of the red big eye Priacanthus macracanthus , a commercially crucial species in the western Pacific and eastern Indian Oceans, by using mitochondrial DNA cytochrome b ( cytb ) gene sequences (1,141 bp). A total of 206 samples were collected from 9 locations, and 101 haplotypes were obtained. Analysis revealed that (1) all haplotypes clustered into two sympatric haplogroups; (2) although the genetic distance between these haplogroups was small, nucleotide substitution patterns indicated distinct evolutionary histories; (3) migration and haplogroup distribution patterns suggested that the two haplogroups may have originated from different sources, eastern Indian Ocean and the western Pacific Ocean; and (4) recent population declines and low nucleotide diversity indicated a need for targeted management strategies. These findings provide valuable insights that can guide fisheries management and future research on the conservation of P. macracanthus populations.