Susceptibility of Marsupenaeus japonicus, P. monodon, and P. semisulcatus to white spot syndrome virus (WSSV)

Abstract

White spot syndrome virus (WSSV) has been detected in cultured and captured shrimps, crabs, pest crabs and other arthopods. In this study, Penaeus japonicus postlarvae (PL28) were experimentally challenged by WSSV via two transmission pathways: immersion and feeding. By 15 days post-challenge, mortality in the immersion and feeding groups reached 88% to 94%. Challenge by immersion produced an earlier onset of mortality than challenge by feeding. Only 1 out of 3 of the tested surviving shrimp from the immersion group was one-step PCR positive, but all 3 tested shrimp were WSSV infected. For the feeding group, 1 out of 3 tested survivors was one-step PCR positive and 2 out of 3 were WSSV infected. All the moribund specimens f or the immersion and feeding groups were one-step PCR positive. The susceptibility of P. monodon, P. japonicus and P. semisulcatus to WSSV was also determined by immersion challenge test. After 15 days, cumulative mortality reached more than 80% in P. japonicus and P. monodon, but only 26%-47% in P. semisulcatus. Almost all of the tested moribund P. japonicus and P. monodon samples were one-step WSSV PCR positive. None of the P. semisulcatus were one-step PCR positive. We concluded that P. semisulcatus is less susceptible than P. japonicus and P. monodon to WSSV infection.