Video credit: G. Venkata Raju (India)
Description: Abdel Rahman El Gamal
The Chinese hatchery system became most popular throughout India especially the efficiency of the system is high and the cost (construction and operation) is less compared to other systems. These hatcheries are used for Chinese carps as well as Indian major carps.
The video shows a spawning tank and three incubation tanks. The spawning tank is with an inside diameter of 8 m and holds 50 cubic meters of water. The inside depth at the periphery is 1.20 m which slopes down to the center at 1.50 m. The design of the spawning tanks allows fertilized eggs along with water to be transferred into incubation tank for hatching. The water flows in the spawning pool create an artificial riverine condition for the fish to breed.
The three other tanks shown in the video are for the incubation and hatching of fertilized eggs. Tanks are circular with about 3.6 m internal diameter. Each of these tanks has two chambers (outer and inner). The inner chamber is encircled with a screen of the right mesh that allows only water to pass through. The tank is often with 9-12 m3 of water holding capacity. These tanks are equipped with outlets through which that hatchling pass through into the larval tanks (not shown in the video). Water speed and direction in these tanks assures favorable circulation of eggs and protect them against mechanical injury.