EFFECTS OF ACUTE STRESS ON THE IMMUNE-SYSTEM OF THE DAB, LIMANDA-LIMANDA

The effects of acute stress on the immune system of the dab, Limanda l imanda, have been investigated using differential blood cell counts an d assays to measure phagocytosis and respiratory burst, together with image analysis and electron microscopy, Significant differences were r ecorded in spleen somatic indices, circulating blood cells and phagocy tic and respiratory burst activity of kidney cells in stressed fish, A significant reduction in splenic erythrocytes was demonstrated by his tology, image analysis and ultrastructural studies. Increased numbers of leucocytes, particularly phagocytes and damaged cells, were detecte d in the peripheral blood of stressed fish along with a decrease in ly mphocytes, 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 activit y, measured by hydrogen peroxide secretion, was also increased in stim ulated kidney cells of stressed fish compared with controls,