A brief description of the layout of the hatchery is given here. As stated earlier, the sea water is drawn into a well by gravitation. If the salinity of the sub-soil water is low, the sea water is directly drawn into a sedimentation tank (3.5 × 2.5 × 1 m.) by using 1 hp motor. The sea water is allowed to settle down. The water in the storage tank overflows and goes to a filter bed (2 x1 x1 m.). This filtered sea water is then let to storage pump (4 × 4 × 1.5 m.). From the pump, this water is taken to an overhead tank by using 7 hp. motor. The overhead tank should be higher to give sufficient pressure for the circulation of sea water in the hatchery. Sea water from the overhead tank on entering the hatchery passes through UV filter. This water is drawn through pipes at various points. In the wet laboratory four one-ton tanks (Fig. 2) are kept on cement blocks (Fig. 6). The cement blocks are arranged in 2 tiers to give sufficient height for siphoning out the water. Under each tank, 12 cement blocks are arranged and over the cement blocks a wooden frame (Fig. 5) is placed. The one-ton tank is kept over this wooden frame to distribute the weight of the tank uniformly. If the wooden frame is not used, the tank will develop cracks due to unequal distribution of weight. Two one-ton tanks are kept outside to maintain the broodstock. When the broodstock and larvae are present in one ton tank, the water is changed daily by siphoning it out. The tanks are covered with black cloth. The water in the wet laboratory is let out into the drainage. The drainage water should not come in contact with the intake water. In the wet laboratory, there is a platform on which a microscope, larval counting chamber, mixie and other equipment can be kept.
The second room is set apart for the micro-algal culture. One fourth of the room is partitioned and used for the stock culture and in this room, one air-conditioner is installed. Four racks (Fig. 7) can be installed in this room. In each shelf of the rack, seven Haufkin's culture flasks (Fig. 8) of 4 litres capacity can be placed. These flasks are arranged in the upper and middle shelves of the racks. Out of four, only in three racks Haufkin's flasks are arranged. In the fourth rack, cultures can be maintained in the test tubes sand conical flasks of different capacities. In each shelf of the rack, four tube lights (40 watts) are installed as shown in the figure. It is better to keep all the chokes of the tubelight outside the stock culture room to avoid excess of heat. All the tube lights should be connected to a timer switch to provide 12 hours light (0600–1800 hrs.). Six racks (Fig. 9) can be installed in the mass culture room. In one rack, four perespex tanks (Fig. 10) can be arranged with two in each shelf. In one shelf at the bottom, three glass carbouys (Fig. 11) of 20 litre capacity are arranged. Four tube lights for each shelf have to be arranged. Here also the light may be provided for 12 hours and the choke should be kept outside the mass culture room. For mass culture, vigorous aeration should be provided.
