Genetic diversity and population structure of cutlassfish (Lepturacanthus savala) along the coast of mainland China, as inferred by mitochondrial and microsatellite DNA markers

Cutlassfish (Lepturacanthus savala) is a commercially important fish species that is distributed in the tropical coastal area throughout the Indo-West Pacific Oceans. However, there have been few genetic studies on this species. Therefore, based on mitochondrial COI gene and thirteen microsatellite DNA markers that have been successfully developed by predecessors, the objective of this study is to assess the genetic diversity and structure of L savala for the first time, using 172 individuals collected from six locations along the coast of mainland China during 2019. High levels of haplotype diversity (0.94) in mitochondrial DNA and the average number of alleles among the six populations ranged from 10.3 to 14.0 in microsatellite DNA data, which showed that all population exhibited a high level of genetic diversity. Analysis of molecular variance (AMOVA) showed that did not indicate any significant genetic differentiation among groups with no relation to the geographic area. The significant genetic differentiation was found in LYG and BH populations revealed that the prevention of gene flow caused by the Yangtze River and the Qiongzhou Strait. The results of STRUCTURE suggested that all populations were admixtures of two clusters, which could be explained only by the high migratory ability of L. savala resulting in extensive gene flow. Analysis of demographic history revealed that L. savala undergo historical lineage diversification and admixture due to the secondary contact based on ABC analysis, and no evidence for recent population bottlenecks were detected. Such study is both practical and theoretical value for genetic improvement, conservation, management, and sustainable resource utilization.