Pathophysiological Studies on Erythrocytic Inclusion Body Syndrome in Sea-cultured Coho Salmon.

Abstract

To study pathophysiological changes of sea-cultured coho salmon affected with erythrocytic inclusion body syndrome (EIBS), hemochemical assessments and lipid analyses were carried out using fish from one net-pen during an outbreak of EIBS.Fish examined were grouped by hematocrit (Ht) values which indicated the disease progression. Few differences in plasma components were observed in fish that were not seriously anemic. In fish with advanced disease (Ht value l20%), values of plasma total protein, total cholesterol, triglyceride and phospholipid were lower and potassium and GPT activity were higher. A decrease in plasma glucose and increases in plasma sodium, potassium and chlorine were observed in moribuned fish. Except for the moribund fish, blood thiobarbituric acid (TBA) values were higher than 20 nmol/ml in almost all of the fish and C22 : 6 level of liver phospholipids decreased as the disease progressed.It was considered that the changes in plasma constituent levels in the diseased fish reflected the effects of anemia.