Effects of Sublethal Nitrite and Ammonia in Oreochromis Niloticus L. Infected with Edwardsiella Tarda

In this study, the effects of sublethal nitrite and sublethal ammonia on experimentally infected Nile Tilapia’s haematological and immunological parameters have been investigated. The groups were K: control group, Group A: ammonia exposed group, AB: infected with Edwardsiella tarda and exposed to ammonia, Group N: nitrite exposed group, NB: infected with E. tarda and exposed to nitrite, B: infected with E. tarda. The LC50 value of nitrite, ammonia and E.tarda were determined and were 8.318, 1.304 and 1.2x10 7 respectively. The erythrocyte sedimentation rate, haematocrit and haemoglobin, were significantly decreased in AB and NB compared with the Group K. Plasma lysozyme activity increased significantly, as did phagocytosis of the head kidney respiratory burst activities and plasma glucose concentration in Group AB and NB were higher than those in Group K. There were slightly higher mean values of plasma lactate in AB and NB than in K. In conclusion of this study suggest that sublethal concentration of nitrate and ammonia with infection have some degree of influence on the haematological and immunological characteristics of Nile Tilapia.