Figure 2 NO, GSH and SOD response in serum of Nile tilapia (O. niloticus) to 〖"KMnO" 〗_"4" (a, c) and FCA (b, d) treatment group, respectively; compared fish with the infected group challenged with S. ferax zoospore 2x10 4 and control group. N=8 fish/sampling time. Values are reported as mean ± SE. Values with a different letter superscript are significantly different between and within groups (p < 0.05).