Finfish Breeding and Hatchery Management

Glass jar hatchery

● The credit of developing India’s first transparent hatching device in which the developing eggs can be watched at eye level goes to CIFRI, Barrackpore.
● In this system, jar hatchery is recommended to overcome the problems of high mortality and high recurring expenditure associated with double-walled hatching hapa,
● Vertical jars made of glass or transparent FRP are suitable for large-scale hatching of major carp eggs and are referred to as jar hatchery
● A battery of conico-cylindrical jars of 6.35 L is provided with water supply from bottom and outlet is provided at the top of the jar
● It can be installed within the hatchery building itself.
● The main components of glass jar hatchery are : an overhead tank, fish breeding tank, incubation and hatching jars, and a spawnery
● The capacity of the overhead tank is 5,000 L which can supply water at one litre per minute for 20 jars
●The spawnery comprises of two cement tanks (1.8 x 0.9 x 0.9 m each) which can hold a nylon hapa measuring 1.65 x 0.8 x 1.0m, projected above the tank and hence deeper than the tank and has an overhead shower for water spray.
●Each jar can accommodate about 50,000 water-hardened and swollen eggs at a time.
●The water flow rate maintained is 600-800 ml/minute.
●This was earlier a very successful system, but the hatchery jars are now obtained against orders only.

Merits :
1. Adaptable for large-scale operation
2. Eggs and larvae are subject to view and easy examination
3. Do not require much water
4. Simple design and less expensive
5. Water quality can be controlled

Demerits :
1. Need constant vigil and care
2. If made of transparent material, it may, with use, become opaque and hence need replacement
3. Can break if made of glass unless it is non-breakable, which is expensive