Genetic diversity of swimming crab (Portunus trituberculatus) populations from Shandong peninsula as assessed by microsatellite markers

► Microsatellite loci were used to evaluate the genetic variability of swimming crab. ► Five wild samples, DY, WF, WH, QD, RZ and one hatchery population, YT were screened. ► All of the eight microsatellite loci screened showed marked polymorphism. ► A total of 40 different alleles were observed over all loci. ► The hatchery population showed significant reduction in genetic diversity.