Henneguya ghaffari sp n. (Myxozoa : Myxosporea), infecting the Nile perch Lates niloticus (Teleostei : Centropomidae)

Light microscopical description is presented for a new myxozoan species, He nneguya ghaffari, which infects the Nile perch Lates niloticus (Linnaeus, 1 758) in Lake Wadi El-Raiyan in Egypt. The spore is characterized by a trian gular thickening at the base of the caudal processes. The relatively long c audal processes run adherent to each other for two-thirds of their length, then bifurcate to very fine processes. Prevalence of infection was 34.6% an d peaked during winter and early spring. The infection was concentrated alo ng the intestinal tract, and in severe cases gills and gill rakers were als o infected. Histology revealed that, in contrast to findings of previously published works on related species, intralamellar plasmodia did not develop inside the blood capillaries of the gills. Intestinal plasmodia were very pathogenic due to their large number and size. These plasmodia caused atrop hy of the muscularis layer, and replaced and distended the submucosal and m ucosal layers. The validity of some Henneguya species in Africa is discusse d.