2.5. Preparation of viral inoculum and challenge trials
Approximately 120 crabs were used in this experiment with an
average body weight of 97.17 ± 10.35 g; males and females were
randomly selected. The crabs were divided into a control group
and three experimental groups for replication designated as WSSVchallenged
group1, group 2 and group 3. There were 30 crabs in
each group. They were maintained at room temperature (28 ± 1 ◦C)
in natural freshwater in tanks (90 cm × 78 cm × 80 cm) with continuous
aeration. They were also randomly selected for routine WSSV
screening using negative staining and nested PCR as described in
Sections 2.2 and 2.3. Healthy crabs were selected in the following
challenge trials.