The objective of this investigation was to study the total prevalence, seasonal Dynamics and diagnosis of
Myxosporidiosis in different freshwater fishes. The present study was carried out on five fish species
(wild and cultured) Oreachromis niloticus, Clarias gariepinus, Mugil cephalus, Lates niloticus and
Ctenopharyngodon idella which were collected from different localities from February to November
(2013). The infested fishes showed no pathognomonic clinical signs except macroscopic creamy whitish
nodules, oval in shape and its number varied from 3-5 cysts. These nodules contained milky fluid filled
with mature spores. The total prevalence of myxosporidiosis was 24.00, 43.65, 57.9, 65.2 and 47.2% for
O. niloticus, C. gariepinus, M. cephalus, L. niloticus and C. idella, respectively. In addition, the highest
seasonal prevalence of myxosporidiosis was found in winter (43.4, 56.1, 71.4, 85 and 66.7%) while the
lowest rate was recorded in summer (8, 30.8, 30, 37.1 and 20%), respectively. The results concluded that
the highest prevalence of myxosporidiosis was observed in L. niloticus followed by M. cephalus then C.
garipinus, O. niloticus and C. idella. The seasonal prevalence of myxosporidiosis was the highest rate in
winter followed by spring then autumn and summer.