Respiratory burst activity of spleen leukocytes in (A)
300 mOsm/kg and (B) 500 mOsm/kg osmolality media after
cultured for 4, 8 or 24 h. Con: control, non-serum added;
FW: added 25 % serum of tilapia in fresh water; SW: added
25 % serum of tilapia in 25 ppt sea water. Data are expressed
as mean ± S.D. (pool sample, n = 8). *(p < 0.05) indicates
statistically significant differences as compared with the control
at corresponding time