spots becoming evident in cuticle, disease signs were
comparable to those seen in penaeid shrimp and included
anorexia, lethargy and whitening of the body.
Deaths occurred from 48 hpi onwards and the LD50
determined when the bioassay was terminated (120 hpi)
for the 3 replicate groups of prawns (105.51, 105.14 and
105.48 LD50 ml−1) was 105.38±0.21 LD50 ml−1.
All prawns injected with undiluted and 10−1 diluted
WSSV-Viet began to show gross disease signs from
24 hpi. Among prawns injected with the 10−2 dilution,
only those in which infected cells were evident when
sampled at 120 hpi showed disease signs from 24 hpi.
Deaths occurred from 48 hpi onwards and the LD50
determined when the bioassay was terminated (120 hpi)
showed disease signs from 24 hpi. Except for no white