Blood profile was studied as affected by different fish species, dietary crude protein, replacements, and additives, as well as diets' types, in laboratorial and field studies. It was clear that most studied treatments (food types, probiotic levels, levels of clover seed wastes, initial body weight, and Teen Barshomy wastes and levels) had been significantly affected most studied haematological and/or biochemical parameters. That means that fish blood constituents are not stable within known ranges, but widely varied according to various environmental conditions.