MFSc

The efficacy of two commercial probiotics, Waves and Epicin on the growth and survival of M. rosenbergii PL and on the chemical and biological characteristics of water and soil were studied. The experimental set up consisted of fiberglass tanks of 70 l capacity with two treatments and a control, each with 5 replicates. Soil from a fishpond was filled to a height of 5 cm and water filled to a height of 25 cm. The post larvae were stocked @ 500 no/m2 and mild aeration provided. Commercial freshwater prawn feed starter 1 (Higashi) was given @ 100% of body weight. Analysis before the introduction of probiotics showed the presence of microorganisms such as E. coli, Salmonella, Hafnia alvei, Faecal Streptococci, Aeromonas caviae, A. sobria, A. hydrophila and Enterobacter aerogenus in the water and soil. Enterobacteria such as Enterobacter aerogenus, Hafnia alvei, Aeromonas sobria and A. hydrophila were present in the PL. The probiotics Waves and Epicin were added @ 0.5 ppm and 0.25 ppm respectively to the experimental tanks once in ten days and the microbiological observations and water quality parameters were studied once in 15 days. The introduction of the probiotics increased the growth and survival and reduced the F.C.R. of M. rosenbergii in nursery system. The species composition of the bacteria in the soil, water and body of the animal were not affected by treatment with probiotics, other than that the E. coli present originally and continued in the control was not detected in the tanks treated with probiotics. The T.P.C. was also less in the treatments compared to the control. Probiotics considerably reduced the level of NH3-N in culture tanks. Epicin was found to have reduced the NH3-N level effectively than the Waves.