Finfish Breeding and Hatchery Management

Unit 4 - Different types of fish hatcheries

4.2. Chinese type of carp hatchery

• Hatching and breeding devices of circular shape and are of Chinese origin are referred to as Chinese carp hatchery.
• A hatchery proper is the most essential component of the modern fish seed farm.
• It is here that fish are bred, eggs hatched and hatchlings produced.
• Further rearing can even be done outside, but according to the latest concepts of a hatchery, up to fingerling rearing is done in the hatchery or the fish seed farm.
• A modern hatchery which incorporates all the essential components and where ecological conditions are simulated is sometimes referred to as eco-hatchery.

The components of a hatchery proper are

1. Ante-tank,
2. Fish breeding tanks,
3. Hatching tanks and
4. Larvae holding tank or spawnery.

• Ante-tank: The purpose of these tanks is to temporarily hold selected broodfish and to acclimatize them prior to injection and they are normally located inside the hatchery building.
• The ante-tanks are normally twins - one each for female and male. A 200 m² (10m x 20m x 1.5m)ante- tank, divided into two identical twins of 5m x 20m can hold 25 sets of broodfish comprising female to male in the ratio of 1:2 i.e. 75 specimens of fish.
• Besides holding broodfish for conditioning, the ante-tanks are also used, in modern hatcheries, for stocking fry or fingerlings prior to sale and also for treatment of diseased or infected fry, fingerling and broodfish. The ante-tank is generally a concrete structure.
• Depending upon the system adopted, the same breeding tank can serve as a hatching as well as larval rearing tank for about 3 days after hatching.
• The hatching tank can itself serve as a larval rearing tank besides a hatching tank or can in turn lead to a larval rearing tank, where the larvae after yolk-sac absorption are given their first external larval food before being transferred to the outside nursery pond.

The merits: The important merits of this system are that it stimulates some characteristics of a riverine habitat where the fish naturally belong, very efficient hatching (almost100%), combines breeding, hatching and larval rearing and suitable for commercial scale operation.

The demerits: Requirement of water is high and in many a hatchery water is in short supply and a large breeding tank is ill- utilized for small scale breeding operations. Further, concrete structures are expensive to install and once installed, subsequent modification becomes virtually impossible.