Effects of Salinity on Some Haematological and Biochemical Parameters in Nile Tilapia, Oreochromus niloticus

Any change in haematological and biochemical parameters could be a predictor of unfavorable environment or effect of different stress factors. The present study was designed to assess different salinity concentration induced changes in some haematological and biochemical parameters in 64 O. niloticus fishes captured from Manzala Lake (Egypt), they were acclimatized and fed with commercial fish diet for one week before starting the experiment for another 2 weeks. Fishes were divided into 4 equal groups assigned as; control, 4g NaClL, 8 g NaClL and 12 g NaClL. RBCs, HCT, Hb concentration, platelets count, superoxide dismutase activity, catalase activity, potassium level and serum total protein were estimated. The HCT, Hb concentration, platelets count and potassium levels were significantly higher in (4gNaClL, 8gNaClL and12gNaClL, respectively). The Superoxide dismutase activity (SOD), total protein, RBCs and catalase activit were significantly lower in (4gNaClL, 8g NaClL and 12gNaClL, respectively) compared to the control group. Other parameters such as WBCs, haematimetric indices (MCV, MCH, MCHC), malonedialdhyde (MDA) level, carbonyl protein (CP), glutathione reductase (GR) activity, as well as serum sodium, glucose, cortisol and IgM, did not show any significant differences in the estimated salinity concentrations.