Abstract Grass carp at a weight of 34.68 + 2 g were gradually exposed to four saline concentrations: tap water (0.1), 3, 6, 9, and 12 gm/litter, the first concentration represented control treatment. Fish fed on diet with protein content 30% for ten weeks. Results growth experiment showed that feed conversion rate was 2.46, 3.58, 4.84, 6.77, -8.56 in fifth treatments, respectively, efficiency 4...