The importance of vitamin C as an immunomodulator and a key nutritional element in modern fish farming in promoting optimal survival and performance. Tracing induced changes in fish by the use of Immunostimulants (Vitamin C), vaccines or environmental stressors such as aquatic pollutants is an important part of present day aquaculture. Natural immunostimulants are gaining wider acceptance because they are biodegradable, biocompatible and safe for environment and human health. These are the products from natural origin. It is well known that these agents stimulate the nonspecific immune...