|Changes in hemopoietic tissue of rainbow trout under influence of stress|
Peters, G.; Schwarzer, R. (1985). Changes in hemopoietic tissue of rainbow trout under influence of stress. Dis. Aquat. Org. 1: 1-10
In: Diseases of Aquatic Organisms. Inter Research: Oldendorf/Luhe. ISSN 0177-5103, more
Biological stress; Cells; Disease resistance; Fish diseases; Fish physiology; Hemopoiesis; Kidneys; Leukocytes; Lymphatic system; Lymphocytes; Macrophages; Spleen; Stress; Marine
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As in higher vertebrates, stress increases the susceptibility of fishes to disease. This effect is accompanied by changes in circulating white blood cells: the number of lymphocytes decreases while the number of granulocytes increases. Investigations were therefore undertaken to determine in what ways stress induces changes in hemopoietic organs, particularly spleen and head kidneys of rainbow trout Salmo gairdneri. Handling and social conflict were used as stressors. These psychic stimuli are typically encountered in aquaculture and under laboratory conditions. Under the influence of both stressors hemopoiesis in spleen and head kidney is disturbed. Blast cells become rare of disappear completely from the tissue. The numbers of mature, intact PMN cells and of small lymphocytes also decrease. Hypertrophic macrophage-like cells with vacuolized cytoplasm appear in increasing numbers. The decreased production of new blood cells and the increased destruction of immune-competent cells still present seem finally to contribute to disease susceptibility under stress.