Pathologic Studies on vitamin c Deficiency In Some Fresh water Fish, During various Ages

Most fish cannot synthesis vitamin C because they do not possess theenzyme L- gulonolactone oxidase, which is required for its biosynthesis.Thus, fish require a dietary source of vitamin C for normal metabolism,health and growth. Vitamin C has many vital functions. It is necessary forformation of intercellular substances like reticulin and collagen. It isinvolved in tooth and bone formation, bone repair and wound healingbeside capillary integrity, maturation of erythrocytes and utilization of ironand maintenance of the normal blood hemoglobin. Vitamin C acts as astrong physiological antioxidant.Four hundred fries (200 tilapia and 200 catfish) with average bodyweight 500, 1500 mg. respectively beside 240 fingerlings (120 tilapia &120 catfish) with average body weight 5 and 10 gram respectively, and 80adults (40 tialapia and 40 catfish) with average body weight 50 and 150gram respectively were collected from different localities and kept in glassaquaria 40 and 200 liter and fed a purified diet deficient in vitamin C for 24 week for adults and 16 weeks for fries and fingerlings. Six groups wereused as a control under the same condition except feeding on a purified diet supplemented by vitamin C 50 mg/ kg of ration for tilapia sp. and 45 mg/kg of ration for catfish. All conditions for the normal growth and health were available. Samples were taken monthly for X- ray photography,necropsy and histopatological examinations. The clinical signs andmortalities were recorded daily.Specimens were collected from the necropsied fish, immediately fixed