LAUSR

Abstract An experiment was carried out to estimate dietary inositol requirement of fingerling Channa punctatus (3.78 ± 0.21 g) by feeding purified diets (450 g kg −1 CP, 18.71 kJ g −1 GE) with eight doses of inositol (0, 100, 200, 300, 400, 500, 600 and 900 mg kg −1 diet) in triplicate groups near to satiation for 12 weeks. Live weight gain per cent (LWG), feed conversion ratio (FCR), protein efficiency ratio (PER), protein production value (PPV) and lipid gain (LG) were found to improve ( P −1 . Hemoglobin (Hb), hematocrit (Hct), red blood corpuscles (RBCs) counts, mean cell hemoglobin (MCH) and mean cell volume (MCV) were found to be directly correlated to the dietary inositol up to 400 mg kg −1 and then plateauing beyond. Liver superoxide dismutases, catalase and glutathione peroxidase activities increased with the increasing amounts of dietary inositol up to the above-mentioned level whereas liver thiobarbituric acid reactive substances activity showed reverse pattern with the increasing doses of dietary inositol from 0 to 400 mg kg −1 . Fish fed 400 mg kg −1 inositol had the highest serum protein and alkaline phosphatase activities than that fed on inositol-deficient diets. However, liver inositol concentration showed a direct ( P −1 and then stabilized indicating the inositol saturation. The dietary inositol requirement of fingerling C. punctatus was estimated by subjecting the LWG, PPV and liver inositol concentration against varying doses of dietary inositol to broken-line analysis which revealed the inositol requirement in the range of 374.1–504.9 mg kg −1 .