Effects of acute stress on the immune system of the dab, Limanda limanda

Abstract

Abstract The effects of acute stress on the immune system of the dab, Limanda limanda , have been investigated using differential blood cell counts and assays to measure phagocytosis and respiratory burst, together with image analysis and electron microscopy. Significant differences were recorded in spleen somatic indices, circulating blood cells and phagocytic and respiratory burst activity of kidney cells in stressed fish. A significant reduction in splenic erythrocytes was demonstrated by histology, image analysis and ultrastructural studies. Increased numbers of leucocytes, particularly phagocytes and damaged cells, were detected in the peripheral blood of stressed fish along with a decrease in lymphocytes, thrombocytes and erythrocytes. Kidney and spleen phagocytic cells showed a stimulation of total activity following stress, but no effect on the phagocytic index was evident. Respiratory burst activity, measured by hydrogen peroxide secretion, was also increased in stimulated kidney cells of stressed fish compared with controls.