The large difference in WSSV infection in the
postlarvae between the two species may be due to the health status of
their broodstocks. In South Korea, all L. vannamei hatcheries have
been using SPF broodstock that has been imported from Hawaii
since 2003 (Jang et al., 2007); meanwhile, the larval production of F.
chinensis depends entirely on wild broodstock this is possibly heavily
infected with WSSV (Jang et al., 2006). Another interesting finding in
the WSSV assays of the postlarvae of two species was the difference
in infection rate among individual specimens. 98.89% individuals of L.
vannamei postlarvae assayed in the present study were WSSVpositive,
but showed a narrow range of infection (0.0–34.3 copies/