Genetic population structure of black marlin (Istiompax indica) within the central Indo-Pacific: Breeding populations defined despite mitonuclear discordance

Abstract:

Genetic data are often used to identify the population structure of commercially exploited marine species. The identification of stocks is critical for fisheries management, particularly in highly migratory species that have few barriers to dispersal. Black marlin Istiompax indica, a valuable commercial and recreational species, may have a genetically homogeneous population structure due to its ability to move large distances. The stock structure of I. indica is unknown, which restricts the ability of fisheries managers to monitor and regulate exploitation of the species. The population structure of black marlin was analysed using 18 microsatellite markers (developed de novo here using Next-Generation Sequencing) as well as sequences from the mitochondrial control region. Tissue samples were taken from five locations in the Central Indo-pacific. Nuclear genetic heterogeneity was found among populations in the Southwest Pacific Ocean, East Indian Ocean and South China Sea (significant pairwise FST values ranging from 0.0127 to 0.03696). In contrast, phylogenetic analysis of the mitochondrial control region was unable to detect contemporary stock structure among geographically distinct locations. Instead, three clades were distinguished, suggesting secondary contact during times of sea level fluctuation. The general value of the microsatellite loci developed was demonstrated through successful amplification in five other species of pacific billfish. The results from this study provide clarity to the stock structure of black marlin in the Indo-Pacific and a firm basis for future research into the global population structure of the species. Information provided …

Año de publicación:

Keywords:

Fuente:

google