Background:
A healthy mother can give birth to healthy offspring since it is widely acknowledged that a mother and maternal environment can have a profound effect on the health and survival of the offspring. Overall health status of brood fish affects breeding performances, quality seed production and protection of offspring at early stages of life. Immunity of brood fish is regulated by seasonal changes such as photoperiods, temperature, adverse environmental conditions, and stress conditions like handling, crowding, and water pollution/contamination, improper nutrition. Maintaining the brood stock immunity - at high level during vitellogenesis and oogenesis, is utmost important for maximum/optimum transfer of maternal immunity to offspring to reduce mortalities at larval/post larval stages. In Indian aquaculture, there is enormous demand for fish seed. At present, only 80% (24,000 million carp fry) of the required fish seed is produced but only 15 % survive in later stage. By 2022, we need approx. 30, 000 million fry. Hatchery owners do not have a proper health management protocol and adopt improper medication during gonadal development High mortality of spawns within few weeks of hatching due to lack of immunocompetency up to 3 weeks of hatching in spawns making them more prone to infection and mortality. Immunity of brood fish varied seasonally with significantly lower during winter season making them more prone to infection and mortality. Both specific and non-specific immune factors were transferred to offspring through egg and persisted up to 3 weeks of hatching. Technology Details:
Immunity of mother fish and its transfer to offspring was modulated by use of suitable immunostimulants maximum 15 days before breeding. An immunostimulant viz. Immunoboost – C was developed, field tested and commercialized for use throughout the country. It is estimated around 30% more carp seed production in Immunoboost – C injected fishes. The Immunoboost-C is also administered to young hatchlings through bath treatment to enhance the seed survivality by more than 50% and to reduce the stress during seed transport.