For therapeutic use of phage under field conditions,
studies were conducted in a commercial shrimp
hatchery with research wing. Nine 500 L tanks were
stocked with 35,000 nauplii of P. monodon and reared
for 17 days through stages of zoea, mysis and
postlarvae. Before stocking, the nauplii were tested
and found negative for WSSVand MBV by PCR. Three
tanks served as control and three were treated with
bacteriophage (109 pfu ml−1) at the rate of 200 ppm
daily (phage concentration in the water was 2×105 pfu
ml−1). Three tanks were treated with antibiotics (Oxytetracycline
5 ppm, Kanamycin 10 ppm daily). Total
bacterial count, luminous bacterial count and total vibrio
count in the water was monitored as described above.
Larval survival was also monitored on daily basis.