EFFECT OF SALINITY LEVELS ON SERUM OSMOLARITY AND RELATED PHYSIOLOGICAL PARAMETERS OF NILE TILAPIA (Oreochromis niloticus) AND ITS RELATION TO
GROWTH PERFORMANCE
Abd El-Ghaffar, H.A.
Spawning and Fish Physiology Department, Central laboratory for aquaculture research, Abbassa, Abu Hammad, Sharkeya.
Abstract
The experiment was performed in the central laboratory for aquaculture researches, Abbassa, Abu Hammad, Sharkeya, Egypt. Experimental fish were collected from Abbassa fish farm and stocked in a fiberglass inside the laboratory for about two weeks for acclimatization before distribution. Four treatments were prepared with different salinities (0.15 ppt “control” T1, 3 ppt “T2”, 6 ppt “T3” and 9 ppt “T4”) for 90 days and use pure NaCl was used for salinity adjustment. At the end of experiment blood samples were collected for blood measurements. The results showed that, water temperature was ranged about 29˚C, the maximum values of Hb and RBCs were recorded in control group (7.32±0.21 g/dl and 2.565±0.023 x 106/cmm) respectively. Minimum and maximum ferritin values were (3.77 ± 0.40 ng/ml
to 6.62 ±0.35 ng/ml) recoded in T4 and control group respectively. The maximum values of TIBC were recorded in control group (216.9±8.5 µg/dl). Sodium and potassium were significantly increased in T4 (172±2.54 m.mol/l and 6.42±0.55 m.mol/l) respectively. The highest osmolarity value was (378 ± 9.6 m Osmol/kg) in T4. The highest survival rate was noticed in control group (95.8±0.7%).
Key words: salinity, Nile tilapia, osmolarity, ferritin, hematological parameters, growth performances, iron and water quality.
