Vertical Jar Hatchery for Fishes

• Ensures 90% survival of fish hatchlings.
• The hatchery consists of a continuous water supply, breeding tank, incubation and hatchery apparatus and a spawnery apparatus.
• The vertical jars are made up of glass, polythene and iron.

Advantages of Vertical Jar Hatchery

1. The greatest advantage of the jar hatchery is its very low water requirement. One unit of 40 jars can handle 20 lakh fertilized eggs in a day and it would need just 20,000 litres of water.
2. It can be operated in a compact area. The space needed to accommodate the 40 jars unit would be around 10 m² or at the most 20 m² and such a unit is sufficient for hatching out 20 lakh eggs.
3. In summer, the water temperature shoots up over 32⁰ C. The hatching will be adversely affected in hapas. But, in jar hatcheries, it is possible to overcome this by air conditioning the room.
4. Developing embryos can be seen with naked eyes and so rectification can be attempted depending on exigencies.
5. A set of 40 jars would cost Rs. 10,000=00 with accessories. These jars last for 10 years. Hence, the cost / year for 20 lakh hatchlings would be Rs. 1000. But in the case of hapas, to handle 20 lakh hatchlings costs Rs. 9000. The hapas last only for two years and involve more labour. This indicates that jar hatchery is more convenient and also more economical cost-wise.
6. In a day, in a space of about 20 m², one can hatch out 20 lakh eggs with a survival rate of about 90%. During the monsoon period about 200 million eggs can be handled in this hatchery.
7. An added advantage of the jar hatchery is that, in the same air conditioned room even breeding can be carried out successfully. Brooders respond well at temperatures of 26-28° C.
8. Adverse water conditions can be changed in a jar hatchery. In summer the hydrogen sulphide content is increased, especially in reservoirs and this affects the hatching in hapas in the ponds fed with the above water. This could be treated in overhead tanks before supply to the jar hatchery.

Disadvantages of Vertical Jar Hatchery

• It is made of glass.
• It is prone to easy damage.
• Difficult to shift to different places and subject to breakage during transport.
• Temperature control system is not provided.
• Metabolites are not removed from the circulating water additional air circulation is not provided.