Water quality management during transportation of fry of Indian major carps, Catla catla (Hamilton), Labeo rohita (Hamilton) and Cirrhinus mrigala (Hamilton)

The effects of various agents viz. Tris buffer, zeolite, 2-phenoxyethanol and Oxyflow in controlling the development of toxic by-products and maintenance of high dissolved oxygen levels during transportation of fry of Indian major carps Catla catla, Labeo rohita and Cirrhinus mrigala were studied. Neomycin sulphate at 20 mg l(-1) was added in each plastic bag containing 1500 fry (L = 30 +/- 0.76 nun, W= 410 +/- 7.66 mg) in 3 l water to control bacterial growth. Each experiment was conducted for 48 h. Zeolite, at 7 g l(-1), was found to considerably reduce the concentration of ammonia resulting in increased survival. Similarly, Tris buffer at 0.01 M and 2-phenoxyethanol at 0.09 ml l(-1) gave 100% survival. Oxygen concentration increased considerably when Oxyflow was applied at 250 and 500 mg l(-1) which resulted in 100% survival of the fry. (C) 2003 Elsevier B.V. All rights reserved.