Histologic findings in white sturgeon challenged by intramuscular injection with Veronaea botryosa at 18 °C. A Liver, with large pale staining area of coagulative necrosis (N). H&E stain, Bar = 200 μm. B Severe splenomegaly, white pulp areas are diffusely accentuated by extensive pale staining sinusoidal edema and congestion. H&E stain, Bar = 200 μm. C Liver, with vascular occlusion (V), associated necrotic debris, perivasculitis and hepatocellular necrosis secondary to angioinvasion by the fungus. H&E stain, Bar = 100 μm. D PAS stained section of liver, corresponding to image (C), reveals large numbers of magenta hyphae extending from the vascular lumen into hepatic sinusoids. Bar = 100 μm. E Heart, with fungal hyphae, macrophages and lymphocytes in the lumen of an epicardial arteriole (arrows). H&E stain, Bar = 20 μm. F Gill, with a collection of giant cells and pigmented hyphae (arrow) at the base of a lamellar trough. H&E stain, Bar = 20 μm.