الفهرس 
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Abstract
A field study was carried out during the period from April 2008 till December 2009 to investigate the relationship between physical, chemical and bacterial quality of pond’s water on fish productivity. Water and fish samples were collected equally from each production units of the farm; hatchery, fingerlings pond and raising ponds (P1&P2) as well as their water supply. Results revealed that the average values of physico-chemical and bacteriological parameters were within the acceptable limits at water supply and hatchery meanwhile, a great variation were recorded in rearing ponds as water in raising ponds; pond (2) followed by pond (1) showed a significant increase (P <0.05) of turbidity (9.1±0.6 and 9.6±0.6), ammonia (0.277 ±0.024 and 0.173 ± 0.012), nitrite (0.99±0.12 and 0.084±0.008), lead (Pb) 0.047±0.03, and 0.039±0.012, cadmium (Cd) 0.012±0.003 and 0.015±0.004, with low dissolved oxygen (5.8±0.02 and 6.2±0.14), respectively. Meanwhile the highest values of nitrate and total alkalinity showed in fingerlings pond were 1.88±0.2 and 275.8±8.5 respectively. Furthermore, bacterial parameters revealed that pond (2), showed the highest values of TC, FC and FS were 27.7±1.9, 14.0±1.8 and 31.0±2.4 respectively, followed by pond (1) then fingerlings pond. Correspondingly, fish samples from raising ponds; pond (2) followed by pond (1) showed the highest level of total bacterial, coliform, fecal coliform count and salmonella compared with other ponds. Subsequently, growth performance; body weight gain & survival rates was higher in pond (1) 32.88 ±4.2g & 96.0±1.7% compared with pond (2) 27.60 ±3.0g & 93.0 ±1.2% resulting from poor water quality which acts as stressors affecting fish health and productivity. Therefore, fish productivity can be enhanced if the water quality in the ponds were maintained at optimum levels.