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Abstract
Vitamins are organic compounds essential for growth, health condition and protecting the body against many diseases (Vitamin-deficiency symptoms) in the most organisms including fish. Vitamin C has been to be necessary for the formation of tooth, bone, and acting as antioxidant, but most of fishes are incapable of synthesizing vitamin C, so it must be included in fish-feeds. In the same trend, vitamin E has been shown to be necessary for growth and good health condition, but vitamin E deficiency has been described in fish, where including poor growth and dermal depigmentations. The present study was carried out in Fish Research Units, Faculty of Veterinary Medicine, Zagazig University. In this study, total number of 160 apparently healthy Nile tilapia (Oreochromois niloticus) and 120 of Nile catfish (Clarias lazera) fingerlings were taken to investigate the effects of both vitamin C and vitamin E deficiencies on the general health, growth performance, and the optimum levels of each. A newly hatched Nile tilapia (Oreochromois niloticus) of 10 days post
hatching larvae were used to investigate the optimal treatment conditions for fish masculinity procedure by either immersion in 17a-methyl testosterone or in
feeds. The results of these experiments could be summarized as :
The results concluded that Tilapia (Oreochromois niloticus) which fed on
50 mg vit C/kg diet recorded the best values of growth performance and
health condition, in comparison with those of the other experimental
groups. On the other hand, these results were noticed many clinical
symptoms in the individuals which received vitamin C deficient diets as
anorexia, retardation in growth, exophthalmia, changes in colour
(depigmentation of skin), abnormalities of their behavioral responses (lost
of reflexes), did not react to external agitation, can be easily caught, and
their escape movement was not energetic.