It is well
accepted that fish phagocytes after activation are able to generate
superoxide anion and its reactive derivatives (i.e. hydrogen
peroxide and hydroxyl radicals) during a period of intense oxygen
consumption, called the respiratory burst [35]. These reactive oxygen
species are considered toxic for fish bacterial pathogens [54].
In the present study, higher respiratory burst activity was observed
in all treatment groups when compared to control. The similar
results were also observed in L. rohita fed with varying levels of
garlic and mango kernel [16,55] and levamisole [51] but vary with
diet containing u-3 fatty acid [52].