Effect of distillery spent wash at different C/N ratio on biofloc based nursery culture of Penaeus vannamei

Biofloc technology is one of the methods to overcome the problems associated with high ammonia-nitrogen and nitrate-nitrogen concentration in the water. The addition of carbon source is one of the practical ways to increase the C/N ratio and to promote the floc development in the culture system. The present research was carried out to assess the effect of distillery spent wash (DSW) at different C/N ratios on floc formation and growth of the shrimp under an intensive culture system.

A 35-day experiment was conducted to study the effect of DSW at different C/N ratios (10, 15, 20 and 25) on the development of biofloc in the nursery culture of Penaeus vannamei. Floc development, water quality and growth performance of P. vannamei were also studied.

It was observed that significantly (p<0.05) higher specific growth rate (12.03±0.15), survival, final weight gain and better feed conversion ratio (1.25±0.02) of the shrimp at C/N 15 treatment. The study also recorded an increase in C/N ratio decreases the growth performance of the shrimp. The present study reported that, in a DSW based biofloc system, C/N ratio of 15 showed a positive effect on water quality parameters, survival and enhanced growth of cultured shrimp.