COMPARATIVE TOXICITY LEVELS OF AMMONIA, NITRITE AND NITRATE TO THE FRESHWATER FISH CTENOPHARYNGODON IDELLA

摘要

The acute toxicity of unionized ammonia, nitrite and nitrate to the exotic carp Ctenopharyngodon idella (Valenciennes) was determined using static and continuous flow through systems for 24 h. The median lethal concentrations (LC_(50)) values for 24 h of ammonia (NH_3-N), nitrite (NO_2-N) and nitrate (NO_3-N) were 0.2092,0.2323,23.40, 21.05,262.50 and 236.30 mg/l in static test and continuous flow through test, respectively. The toxicity is in the order of NH_3-N > NO_2-N > NO_3-N.