EVALUATION STUDIES ON THE RELATIVE EFFICACY OF AEROBIC MICROBIAL FLOC(AMF) DRIVEN RACEWAYS AND LINED PONDS FOR THE NURSERY REARING OF PACIFIC WHITE SHRIMP, Litopenaeus vannamei

M. Menaga1, S. Felix2* and N. K. Chadha3
1. PG Scholar, Division of Aquaculture, ICAR-Central Institute of
 Fisheries Education, Mumbai
2. Dean, Fisheries College and Research Institute, Ponneri, Chennai
3. Principal Scientist, Division of Aquaculture, ICAR-Central
 Institute of Fisheries Education, Mumbai
*Presenting author: menaga.aqc14-16@cife.edu.in

The disease outbreaks on commercial shrimp farming in the recent years has made a considerable impact for the significant operational management for sustainable production. Shrimp culture under limited discharge can increase biosecurity and minimize losses to disease outbreaks while reducing negative environmental impact.Operating sustainable biosecure shrimp production facilities under greenhouse enclosed raceways and super intensive lined ponds, dictates the incorporation of aerobic microbial flocculent technology for the efficient  nutrient recycling of the wastes and metabolites produced by these systems.

A 28-days nursery study was conducted in two 50m3 greenhouse-enclosed nursery raceways and 100 m3super intensive nursery lined ponds to evaluate the efficiency of Aerobic Microbial Floc production on selected water quality indicators, growth, survival, and zootechnical performance of Litopenaeus vannamei.The raceways were stocked with PL10-12,(0.02 ±0.01gm) at a density of 6000 PL m3. All raceways were equipped with high pressure rapid sand filters, a pump, a center longitudinal partition over a 5.1 cm PVC pipe with nozzles and eighteen 5.1 cm airlift pumps.Similarly the super intensive nursery lined ponds were stocked with PL10-12,(0.02 ±0.01gm) at a density of 2300 PL m-3. Shrimps were fed six times a day with a commercial diet containing 30% crude protein. Throughout the  experiment, nitrogen of the ration was controlled using a carbon/nitrogen ratio of 15:1.Carbohydrate Enriched Distillery Effluent (MF-CEED)  was used as organic carbon source (40% carbon) to keep ammonia levels (TAN) less than 1 mg L-1.Mean wet weight was sampled once per week to estimate the weight gain and to adjust the ration feed. The nursery raceways  had higher survival (92.8% and 89.6% vs. 84.7 and 87.5%), yield (3.1 and 2.89 kg m-3 vs. 2.9 and 2.74 kg m_3) and FCR (1.2 and 1.3 vs. 1.36 and 1.64) but greater mean final weight was found in nursery lined ponds (1.01 and 1.2 g vs. 0.73 and 0.63 g). Selected water quality parameters like  ammonia, nitrite, nitrate, alkalinity, pH, salinity, TSS were monitored daily. All water quality parameters were within the range suitable for Litopenaeus vannamei culture. Nitrite-nitrogen was significantly lower in the line ponds, whereas reactive phosphorus, turbidity and algal density were significantly higher than compared to raceways. This study demonstrated the feasibility of producing healthy juveniles of the Pacific white shrimp under aerobic microbial flocculent technology in super intensive raceways with good survival, yield and FCR in compensatory growth pattern.