Fish aquaculture refers to the farming of fish under controlled conditions in freshwater or saltwater. The purpose of fish farming is to enhance fish production and to offer protection for rare species. At present, the current aquaculture practice comprises majorly tilapia, yellow perch, walleyes, trout, catfish, largemouth bass, koi/carp, shiners, bluegills, and sunfish production worldwide. Fish vaccines are used to prevent fishes from any kind of disease or infection.
With the continued growth of aquaculture, hundreds of thousands of fish are raised in confined spaces and in close proximity to each other. As a result, infectious fish diseases are spreading faster than ever before.
Image Credit: aquatactics
All aquaculture facilities are vulnerable to disease outbreaks because many opportunistic disease-causing bacteria, viruses, fungi and parasites are present in the environment or may be found on some fish that are not showing signs of disease. Vaccination is a proven, cost-effective method to prevent infectious diseases in animals.
Fish vaccines work by exposing the immune system of fish to part of a pathogen or the entire pathogen (antigen) and then allowing time for the immune system to develop a response. Vaccines also help fish build up a memory to accelerate this response in later infections by the targeted disease-causing organism.
There are many types of fish vaccines, and new kinds are continuously under development. All fish vaccines currently in use can be roughly divided into two major categories: killed fish vaccines and modified live vaccines.
Killed fish vaccines are comprised of killed, formerly pathogenic bacteria – for example, bacterins. Killed fish vaccines work by stimulating the humoral antibody-related system of the immune response.
Modified live vaccines are comprised of live microorganisms that have been grown in culture and no longer have the properties that cause significant disease. Live attenuated vaccines work by stimulating both cell-mediated and humoral immune responses.
Tilapia is an attractive species for aquaculture, reaching harvest size in 6-7 months; and it is now the second most predominant aquaculture species globally after carp. They are farmed in many low and middle-income countries (LMIC) and provide an important source of revenue for many low-income families. Disease in tilapia culture is associated with intensification of the farming system, and both bacterial and viral diseases are severely impacting on the expansion of tilapia farming.
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