Fish Stress In Fish

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compounded stressors. In both cases there is a genetic factor involved in both the host and pathogen involved. Lastly, Harvesting and shipping probably represent the most significant stress because of changes in water pH, temperature, ammonia, salinity, etc during the transportation and holding processes. Most mortality occurs at or near the time of containment change but acclimation can help fish. Fish brought in a tank are already stressed. This is why it is so important that the tank must be in an ideal condition and the acclimation process must be followed carefully, so as not to further stress the fish. The unfortunate truth is that the majority of fish mortalities occur at or near the time of entering a new tank and only through an appreciation…show more content…
According to Branson (2008) first level response to stress relates to light and short-term stress. This kind of stress can trigger the release of hormones that put the body in a high alert state. If they don’t persist too often, their impact on rearing performance are moderate to non-existent. Stress is accompanied by the release of the hormone cortisol for example and this hormone is accountable for many of the negative health effects brought about by stress in fish. These may include a negative effect on reproduction as well as digestion. Cortisol also lowers the effectiveness of the immune system responses thereby allowing parasites, bacteria, viruses and fungus to effortlessly infect stressed fish and cause disease and death. Stress induced production of cortisol and adrenaline alters the total number of circulating white blood cells. Numbers of lymphocytes (antibody producing cells) decreases following stress. Which means that the specific immune system is down-regulated in the face of a stressor, putting the fish at risk of being prone to any number of stress induced infections and…show more content…
In order ensure that the water quality is always high and optimal for the survival of the fish, first and foremost the carrying capacity of fish in ponds and tanks must never be exceeded. In addition, water quality parameters should always be closely checked and monitored. Dissolved oxygen levels should be maintained above 5 mg/L. this is because sub-optimum levels of dissolved oxygen, while not immediately lethal, may nonetheless stress fish, resulting in delayed mortality. The accumulation of organic debris, nitrogenous wastes (ammonia and nitrite), carbon dioxide, and hydrogen sulphide should be avoided at all times as they too are a major cause of stress in fish. Lastly, appropriate pH, alkalinity, and temperature for the species should be maintained so that the environment is perfect for the fish (Rottmann, 2005). Following these water management practices will ensure that stress is reduced along with the chances of recurring diseases and

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