Abstract. - Paciflc threadfln, Polydactylus sexfilis, a
highly desirable food fish in Hawaii, has been raised by
offshore-cage culture in a large scale. To develop an effective
genetic tool to monitor the broodstock resources and
their mating patterns, we identified microsatellite loci of
Pacific threadfin. Genotyping and analysis of 10 microsatellite
loci in the wild and captive broodstock populations
did not indicate significant differences among these populations.
Five polymorphic microsatellite loci were further
selected for the development of a parentage assignment test.
Parental assignment analysis of one broodstock population
showed that 90Vo of the offspring ffom three consecutive
spawning events were successfully assigned to their specific
parent-pairs. These five microsatellite loci provide an
accurate and cost-effective method to assess the genetic
variability and mating pattems in Pacific threadfin.