بررسي نقش زيوليت طبيعي در كاهش مسموميت با آمونياك در قزل آلاي رنگين كمان

Study of natural zeolites efficiency for reduction of ammonia Toxicity in rainbow trout (Oncorhynchus mykiss)

The role of natural zeolite efficiency for absorption of ammonia in rainbow trout has been studied. The fish weight were 9.5-21 grams that exposed to four different concentrations of 10-25mg/I (10,15,20,25 mg/1) total ammonia nitrogen. A group of 13 fish considered as control. Lethal and sublethal concentrations of during 24 hours determined. Under stable temprature and pH condition (T= 16+1°c, PH = 7.7-7.8) the lethal concentration of total ammonia nitrogen was 25 mg/l. In lethal concentration of ammonia different amounts of zeolite (2,5,10.13,15 gIl) were used. Application of 15g/I could prevent mortalities. Samples were taken from liver, gill and kidneys of fish (exposed lethal ammonia as groups with only zeolite) and histopathological sections were prepared. The histopathologic lesions were studied. The major lesions in the gills were hemorrhag, hyperplasia, edema and epithalial cells necrosis. In the kidney lesions were degenerated tubules of kidney, expansion of Bowmanʹs capsule, hemorrhage and hyperamia. In liver the lesions were hepatocytes necrosis, hemorrhage and hyperamia.