Fig. 3

Histopathological findings of gills. (a-b) Mild to severe infestation of secondary lamellae of gills with cysts of Acanthamoeba sp. (a) Lamellar epithelial hyperplasia (H) and interlamellar vesicles formation (V) and cysts (arrowheads). (b) Numerous cysts (arrowheads) of Acanthamoeba sp. and lamellar epithelial hyperplasia (H) are seen. (c-d) Higher magnifications show trophozoite (arrow) and cysts (arrowheads) of amoebae trapped inside the hyperplastic epithelial tissue. Interlamellar vesicles formation (V) are seen (H&E).