This feeding trial was carried out using 33 tanks of capacity 150 L
(50×60×50 cm). These tanks were installed in a water recirculation
system which included a settling tank, a biological filter and a pump.
At the beginning of experiment, 11 groups of shrimps were randomly
distributed from the holding vessels to the feeding tanks (30 shrimps
per tank). Each diet was provided to 3 tanks and the daily feed ration
was fixed to 5% of the initial shrimp weight. Shrimps were fed by
hand twice daily at 8 h and 17 h. At each feeding, the diet corresponding
to each tank was distributed over one feeding tray of 30 cm diameter.
The feeding trays were removed 3 h after each feeding and the
uneaten feed was collected separately from each tank and frozen at
−20 °C. At the end of experiment, these uneaten feed of each tank
were dried at 105 °C until constant weight and then weighted.