EFFECTS  OF  MAGNETIC  WATER ON THE GROWTH  PERFORMANCE  AND SURVIVAL  OF HYBRID RED TILAPIA   Oreochromis niloticus  

Environmental factors affecting living animals, including fish, are divided into two types: changeable (biocoenotic, climatic etc.) and stable, or relatively stable (gravitation, earth magnetism). Water is needed to transport compounds via the blood, to maintain cellular structural integrity, regulate temperature, etc. (Reuter, 2004). Restructured water or magnetic water (MW) can be formed using permanent magnets. Magnetically treated water has its effect on the human body when taken internally and regularly for a considerable period of time (Lam, 2001). Therefore, this study was conducted to assess the effects of MW on growth performance and survival of red hybrid tilapia Oreochromis sp.

Experiment was carried out between September to December 2015 in Aquaculture Research Station, UPM, Puchong, Selangor, Malaysia. Red hybrid tilapia Oreochromis niloticus fingerlings were acquired from local supplier, then acclimated to the experimental conditions for 2 weeks. Treatments were control and three strength of static magnetic fields (SMFs) of (0.2, 0.3, and 0.4)T.  Randomly, 240 tilapia were distributed in 12 aquaria (n=20) and divided into four different groups, with each treatment triplicated. Temperature was kept at 26 - 29 °C with dissolved oxygen greater than 5 mg/L. Experimental fish were fed twice daily (0900 and 1600) at 4% body weight per day with commercial fish pellet containing 34% crude protein.

Both the weight gain WG and specific growth rate SGR of the animals exposure to the different SMFs were significantly different (P<0.05) compare to the control. The highest values, 12.11 g and 2.68 % respectively were recorded in treatment 0.4T. While the lowest survival 93 % observed in the control was significantly different from other treatments. These results indicated the effect of magnetism the living cell.  Earlier researches showed that the equilibrium of living cell can be restored with the help of magnets. Water passed through the magnetic field acquires finer and more homogeneous structures. Based on the results obtained, the water treated by static magnetic fields could positively influence the growth, weight gain and survival of hybrid red tilapia fingerlings.