Determination of Lethal Concentration in Acute Toxicity of Ammonia and Nitrite in Common Carp (Cyprinus carpio

Inroduction & Nitrogenous compounds can be toxic to aquatic animals. The objective of this study was to evaluate the acute toxicity of ammonia and nitrite and behavioral changes to common carp fingerlings in exposed tothe two materials.
Method sand material Four hundred fingerlings with average weight of 40.51 ± 5.8 g were randomly selected and were then exposed toammonia and nitrite in 6 treatments (100, 110, 120, 130, 140, 160 mg/l ammonia and 450, 500, 530, 550, 560, 600 mg/l nitrite). Mortalityand behavioral changes were observed during 96 h, Finally LC50–96 h of ammonia and nitrite for these 6 treatments were estimated.
Resul tsLC50–96 h for ammonia and nitrite was estimated at 102.45 and 512.46 mg/l respectively. The maximum acceptable concentration (MAC) of ammonia and nitrite were determined 10/24 and 51/24 mg/L respectively, in the common carp fry.
Conclusion The results for the LC50 in 96 h showed that with increasing concentrations of ammonia and nitrite, the mortality increased.However in comparison with other investigations that have been done in lower water hardness and salinities, the LC50 was higher. Therefore it may be concluded that ammonia and nitrite toxicity in Khuzestan condition may have lower risk of happening