International Journal of Fisheries and Aquatic Research

Authors
L Roselin Rajathi, R Niranjani, R James

Abstract
Effects of ammonia toxicity at different levels of pH on growth, organic reserves, respiratory enzyme activities and blood parameters were studied in L. rohita for 30 days. The rate and efficiency of conversion or growth were high in NH₃ + pH7 group followed by control and NH₃ + pH8 groups. However, other exposures of NH₃ + pH 6 and 9 showed a drastic and negative reduction in the rate and efficiency of conversion in L. rohita. The FCR value observed in NH₃ + pH7 and control groups was low as compared to other groups. The tested proximate compositions were also significantly (P < 0.05) reduced in fish exposed to NH₃ alone and NH₃ with acidic (pH6) and alkaline medium (pH9) as compared to other exposures. An oxidative enzyme, succinate dehydrogenase (SDH) activity and the blood parameters, RBC count, Hb count, Ht, MCV, MCH and MCHC values were high in control and NH₃ + pH7 groups and it significantly (P<0.05) declined in fish exposed to ammonia with increasing and decreasing of pH levels. The glycolytic anaerobic enzyme, glyceraldehyde dehydrogenase (GDH) and WBC count and ESR values showed the reverse trend against SDH activity.