Study was carried out on experimental acute ammonia toxicity in common carp ( Cyprinus carpio) using static water method. Carps with average weight 570 grams were exposed to five different water ammonia levels ranging from 60-150 mg/liter total ammonia nitrogen (22.2 to 75.5 molcular ammonia nitrogen). A group of 15 fish were also used as control groups. LC50, serum enzymes (ALT, AST, ALP, LDH), urea and cholestrol levels were measured after 24 hours. Under optimal environmental conditions (20-22”C, pH: 7-7.2 and 6-7 mg/L dissoleved oxygen) LC50 averaged 123 mg/L total ammonia (45.5 mg/L molcular ammonia) after 24 hour. In comparison with control group, the ALP level in the serum of all group were significantly higher than control group. LDH level of group with 150 mg/L total ammonia and Urea level of group with 130 and group with 150 mg/L total ammonia was also significantly higher than control group. There was no significant differece in other enzymes and cholstrol level between experimental groups and control group.
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