Striped catfish (P. hypophthalmus) fingerlings were bought from the
Research Center of Aquaculture Seed Production in An Giang province.
The fish were treated with a 3% NaCl solution for 15 min on arrival to
eliminate ectoparasite infection, and were reared and quarantined in a
composite tank (3 m3 of water) for one month to acclimatise to indoor
conditions. Fish were selected randomly from the rearing tank, weighed
and then transferred to the experimental tanks one week before the
start of the experiment for acclimatisation to experimental conditions.