The shrimps were fed commercial food pellets
(3% body weight d−1), and the water was completely replaced every
3 d. Mortalities were recorded every day for 30 d. Whenever a dead
shrimp was observed, it was collected, washed in sterilized seawater, and 100 mg of gill tissue collected and stored at −80 °C. A gill sample
was collected similarly from each of the shrimps that remained alive
after 30 d.