Gill and haematological alterations in <i>Macrobrachium amazonicum</i> adults in acute exposure to ammonia and nitrite isolated and combined

The present study evaluated the isolated and combined effect of total ammonia nitrite on Macrobrachium amazonicum adults through median lethal concentration (LC5096h), histological analysis gills differential haemolymph cell counts. Prawns (n = 640; 9.8 ± 0.9 cm 8.22 1.29 g) were subjected to an entirely randomised design in a 4 × factorial scheme. Individuals exposed (0, 18, 36 72 mg/L) 1, 2 alone combination. Interaction between compounds was determined by summing additivity substances (S) calculating index (AI). LC5096h 27.98 mg/L for 1.87 nitrite. Total showed 22.36 1.17 mg/L, respectively. sum ranged from 2.70 1.42 AI indicated that toxicity mixture 1.70 0.42 times lower, indicating antagonistic compounds. High haemocyte counts (THC) observed at higher concentrations both shorter exposure time. Reduction THC treatments with longer Differential similar treatments. Increases extent regressive damage organ (Iorg) values occurred increasing Mild moderate presence progressive intermediate concentrations, which elevated Iorg values. interaction promoted reduction mortality compared treatment Thus, results obtained guide decision-making production systems, are currently based studies where acting isolation.