Infection of Nile tilapia, [oreochromis niloticus] by a freshwater ciliate, trichodina heterodentata [Duncan, 1977] in Egypt and its treatment

An outbreak of Trichodinosis among freshwater, cultured Nile tilapia [Oreochromis niloticus] is described. Heavily infected fish showed severe respiratory manifestations typified by swimming near the surface of the water wit opened mouth and increased operculm movements, hyperrritability, heavy mucus secretion and discoloration. The morphological characters of the detected ciliate was proved to be Trichodina heterodentata. 100% of T. heterodentata were killd by immersing the infected fish for 10 min in 25 mgl[-1] sodium chloride, 0.001 mgl[-1] acetic acid solution or 0.005 mgl[-1] formalin. Other chemicals were also tested for their therapeutic properties against T. heterodentata