Effects of ammonia on juvenile silver perch (Bidyanus bidyanus)

Continued development of commercial pond culture of silver perch (Bidyanus bidyanus) depends on determining concentrations of water quality variables that limit production. The effect of ammonia on the short-term growth of juvenile silver perch was evaluated in a 39-day experiment. Survival was not significantly affected by exposures up to 0.36 mg l-1 un-ionised ammonia-nitrogen (UAN), the highest concentration tested in this study. Growth was reduced at 0.36 mg l-1 UAN. The EC5 (the concentration at which growth is reduced by 5%) was estimated to be 0.06 mg l-1 UAN. Some changes in gill histopathology were observed in fish exposed to ammonia. (C) 2000 Elsevier Science B.V.