them to the laboratory culturing system. At the beginning of the
test, the fish, with an initial mean body weight of 18.04 ± 0.92 g,
were randomly divided into fifteen groups of 20 fish each (5 treatments in triplicate). Each group of fish was stocked in a 0.21 m 3 indoor tank with a freshwater input of 0.5 l min − 1. The oxygen level