Sporozoan infection in cultured Sparus aurata L. and wild Siganus luridus.

White nodules containing intracellular ovoid Sporozoans were observed in internal organs (kidneys, liver and gut wall) of cultured Sparus aurata and in the liver of wild Siganus luridus in the gulf of Aquaba in the Red Sea. Nodules consisted of parasitised hypertrophic macrophage-like cells enclosed in a well-defined collagenous fibrous capsule. These parasites are evidently the cystozoite stage of a haemogregarine.