NUTRITIONAL AND ENVIRONMENTAL TOXICOLOGICAL INVESTIGATIONS ON FISH FARMS IN FAYOUM GOVERNORATE, EGYPT

Document Type : Original Article

Authors

1 Faculty of Agriculture, Ain Shams University

2 National Institute of Oceanography and Fisheries.

3 National Institute of Oceanography and Fisheries

Abstract

This study was carried out in two fish farms in El- Fayoum Governorate to investigate water quality, evaluate the effect of chemical fertilizers and artificial diet on the performance and feed efficiency of Oreochromis niloticus and Mugil cephalus, and determine pesticide residues in water and reared fish. Average values of water temperature in fish farms and water source ranged between 25.6 and 30.6°C. The highest values of dissolved oxygen were observed during April while the lowest values were found in June and July. There was a negative relationship between water temperature and dissolved oxygen, a positive relationship was found between temperature and water salinity. The highest values of weight gain (270.90, 269.20g), specific growth rate (1.15,1.16), feed consumption (240.60, 270.48g) and feed conversion ratio (0.89, 1.01) of O. niloticus and M. cephalus, respectively were found in fish fed on artificial feed and reared in fertilized ponds when com- pared to fish fed on artificial dictionly or reared in fertilized ponds without supplementary feed. The pesticide residues of chlorpyrifos ethyl and fen- propathrin were detected in water at mean levels ranged 0.10 0.25 mg/l. Both fish species con- tained fenitrothion residues at values (0.525 mg/ kg and 0.255 mg/kg for O. niloticus and M. cephalus, respectively) which are higher than permis- sible limits. Although the residues of fenitrothion and carbaryl were not detected in water, they were found in both fish species which could be at- tributed to the ability of these pesticides to bioacumulate in the aquatic organisms.

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