MUD CRAB FATTENING IN COMPLETE RAS SYSTEM – A WAY TOWARDS SUSTAINABILITY

The "Fattening of mud crab in RAS system" is the system composed of Mud crabs (Scylla serrata) are fattened in boxes which is in vertical arrangement shown in Fig.1. Mud crabs below the average weight of 250gms can be fattened. Here we can use 100 boxes connected with PVC pipes for inlet and outlet flow of water. Apart from that, we use three tanks for holding water for whole fattening period, since it is a RAS system 10% of total volume of water is recycled per day. Filtration process should be done in three ways Viz, sand filtration, Bio filtration and UV-filtration. Minimum two submersible pumps should be used for making proper flow of water into the boxes. This system can be installed in a small room. It is a semi-intensive culture system where proper maintenance is needed shown in Fig.2. Feeding should be done at 6% of its Body Weight. Feed given includes small trash fishes like oil sardines, tilapia fishes, etc. The initial investment for this fattening system is of Rs.7 Lakh/- which is lower compared to other fattening systems.It is more sustainable compared to other types of mud crab fattening processes.