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Nursery system for carp species

by Md. Golam Azam Khan

Anursery is a facility where fish seed (spawn, hatchlings or fry) can grow. Efficient fishpond culture requires special preparation of nurseries for receiving spawn and hatchlings. The ideal size of a nursery is 0.02-0.05 ha with a depth of 1.0-1.5 m. The following is an example of a 0.02-ha nursery as prepared in Bangladesh for 15-20 days.

Pond preparation


Before the hatchlings/fry are introduced to a new environment, it is important that the temperature inside the plastic bag is approximately the same as the pond water.

Place the bags, unopened, in the pond for 10-15 minutes. Open slowly and introduce small quantities of pond water to equalize the temperature. The fry is now allowed to swim into the pond.



Care of fry/fingerlings

Harvesting and transportation

Before transporting, it is important that fingerlings are conditioned. The principle behind this is that they have time to empty their guts before being packed in high densities, so that the pollution of the water in the transport container through excreta is reduced. Clean water from a tube well should be used for conditioning the fingerlings.

Traditionally, young fish are transported in clay or aluminum pots. Recently, the use of plastic bags with compressed oxygen is becoming more widespread, as this allows the fish to be transported in higher densities and longer distances with substantially less mortality. Approximately, 5 litres of water and 15 litres of oxygen are placed in each bag (assuming plastic bag volume is 20 litres).

Budget (in Taka) for a 0.02 ha nursery pond preparation for fingerling production


Draining/refilling or poisoning of pond


Lime (5 kg)


Cattle dung (200 kg)


1.75 kg urea and 2 kg triplesuperphosphate


Dipterex 0.2 kg


60 000 carp hatchlings


Supplementary feeds: 20 kg mustard oil cake + 10 kg rice or wheat bran and 4 kg fish meal


Netting, labour and others



1 480

Income from sale of 30 000 (3.5 - 4.5 cm) fry/fingerlings

3 000


1 520

1992: US$1 = TK38

Issues for further consideration

From experience, farmers who adopt these techniques are relatively resource-rich and/or have had access to specialized information. Options for sanitation of nursery ponds (e.g. to eradicate aquatic insects that prey on fish larvae) that do not involve the use of dangerous chemicals should be used, e.g. higher levels of quicklime, eradication of pest habitat and continual trapping and removal of pests, etc.

Many nursery operators do not have access to tube-well water, and to condition fish under this situation, farmers may need more detailed information. The conditioning process has more important details, such as what exactly is done and what fish are in good condition and suitable for transporting.

The role of women may be very marginal in Bangladesh nursery systems (from where this example is taken) but in other locations in Asia they represent a major part of the labour force. The methods described are broadly similar to those used elsewhere by commercial nursery operators although they tend to be most intensive in Bangladesh. There they also use the practice of fry and fingerling production in the same pond (one-tier system) in bigger ponds.

The practice of fish seed rearing is followed by a large number of small-scale farmers in Bangladesh, who themselves do not necessarily grow fish to market size. This part-time occupation may be an option for other farm families in areas where the availability of fish seed is still a limitation in the popularization of aquaculture.

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