Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 7, 2001
Publication Date: July 23, 2001
Citation: KLESIUS, P.H., SHOEMAKER, C.A., EVANS, J.J. DISEASE PREVENTION IN CHANNEL CATFISH, TILAPIA AND HYBRID STRIPED BASS CULTURED IN EARTHEN PONDS AND WATER RE-USE TANK PRODUCTION SYSTEMS MODEL. BIOSECURITY IN AQUACULTURE PRODUCTION: DISEASE PREVENTION. 2001. Technical Abstract: The impact of infectious diseases remains one of the limiting factors to successful economic production of fish. Infections by bacteria, viruses, fungi, parasites and rickettsia-like organisms are the cause of diseases that are characterized as acute, chronic or asymptomatic in fish. Disease is an altered state of normal physiology that is the result of complex biological interactions between the fish and infectious agent(s). Thus, the occurrence of disease is an interaction between the health status of the fish, and infectious microbes present in the fish and the environment. However, environmental factors can also influence the health status of the fish. There is an increasing awareness that stressful environments, husbandry practices and/or infection by other microbes can suppress the immune system of healthy fish which results in an increased risk of disease, especially in a production system contaminated with infectious microbes. We propose a disease continuum model to help explain the weakening of the immune system against microbes as the results of neuroimmune changes caused by environmental, husbandry stresses and sublethal exposure to infection or neuroimmuno- toxin. Catfish, tilapia and hybrid striped bass are susceptible to infection by many infectious microbes, although unique susceptibilities varies with fish species and species of microbes. Further, diseases encountered in fish cultured in earthen pond compared to tank re-use water systems are often different due to differences in environmental conditions and husbandry practices between these systems. A carefully designed health management plan is a key to the prevention of diseases. Among the components of the health management plan are early detection of pathogens by monitoring and surveillance of brood stock, young of the year and growout fish. The quarantine of fish obtained from outside sources until shown to be free of pathogens is equally important. Vaccination of young fish before growout to ensure fish immune to diseases is a must health practice. Maintenance of environmental conditions minimizing stress, optimizing fish densities, using appropriate diets and feeding practices that are optimal for disease resistance and sanitation of equipment and facilities are also a necessity. Finally, instruction in husbandry practices which emphasize how to prevent the introduction and spread of diseases needs to be presented to all personnel.