Lesions observed in organs of Chinese sturgeon infected by S. iniae. The primary lesions in the heart include interstitial edema, enlargement of stroma as well as thickening of the pericardium (A). In the liver, hepatocytes were characterized by steatosis (B). Brain structure is disorganized with swollen and loose tissues (C). In the spleen, the boundaries of red and white pulps were unclear as well as splenic lymphocyte necrosis (D).