After the shrimp were harvested, routine
pond preparation was carried out by removing the
sludge from the middle of the pond. Seawater was
pumped into three ponds to a depth of 1.5 m
through a bag filter of approximately 26 mesh/
inch2. One week later, specific pathogen free (SPF)
PL10 determined to be free from white spot
syndrome virus (WSSV), Taura syndrome virus
(TSV) yellow head virus (YHV) and
microsporidian (Thelohania sp.) by polymerase
chain reaction (PCR) and reverse transcriptase
polymerase chain reaction (RT-PCR) assays, were
stocked into each pond at 125 PL/m2. Commercial
pelleted feed was provided throughout the culture
period. No water was exchanged during the first
40-50 days. Thereafter, more water exchange was
required to maintain optimal water quality,
particularly during the month before harvesting
the shrimp.