Abstract
A mass mortality of cultured rockfish Sebastes schlegeli (138-145 g in body weight) occurred in the spring of 2001. Histopathological examination revealed necrotic lesions, aneurysms, hemorrhage, hyperplasia of epithelial cells and lamellar fusion in the gill tissues. Gramnegative bacilli were observed in the gill lesions. In some fish, necrotic foci due to bacterial invasion were observed in the splenic ellipsoid, hematopoietic tissue of the kidney and myocardium. However, no bacteria were isolated from the liver, kidney, spleen or brain.
