Nursery system for carp species

A nursery is a facility where fish seed (hatchlings/fry) can grow. Efficient fish pond culture requires special preparation of nurseries for receiving spawn and hatchlings. The ideal size of a nursery is 0.02 0.02. ha with a depth of 1.0 - 1.5 m.

POND PREPARATION (0.02 ha)

Remove all aquatic weeds (Day 1).

Drain or poison the pondwith Plscide-Phostoxin or Cellphos @ 1
tablet/210 cu ft water (Day 2).

Apply 5-6 kg lime which helps to release food nutrients available and to kill pathogenic organisms in the pond (Day 16).

· Refill water if necessary and fertilize (Day 19).

Apply fertilizer 3 days after lime application and 7-10 days before stocking.

· The most basic and reliable test involves filtering approximately 50 1 of water through a fine mesh into a 2.5 cm diameter specimen tube.

· Alternatively, a very simple field test in non-muddy water is to dip one's hand in the water to the elbow. If the hand is no longer visible, the plankton is probably sufficient.

STOCKING

Apply 80-100 g Dipterex at least 20-24 hours before stocking to kill the back swimmers or other aquatic insects in the pond (Day 29).

· Stock 60,000-70,000 hatchlings of 4-5 days old (200-250 9). The hatchlings should be of same age, uniform size, vigorous and released either in the morning or late afternoon (Day

Stocking Procedures

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.

FEEDING

· It is often difficult to maintain a high level of natural food for growing fry and supplementary feeds become necessary (Day 31). A mixture of finely powdered oil cake (soya beans, mustard, etc.), rice or wheat bran and fish meal in the ratio of 5:4:1 is to be supplied to try daily.

Feeding

CARE OF FRY/FINGERLINGS

· Check the pond daily and see if there is an excess of green algae then; stop, application of supplementary feeds. Remove frogs/snakes, if any, in the pond. Increase feed by 10% of the rate mentioned above if the growth of the fish is not found steady and good.

HARVESTING AND TRANSPORTATION

· Harvest the try/fingerlinggs (Day 60) by using fry catching net, either in the morning or late afternoon and keep them in the enclosure (hapa) or cistern at least 3-4 hours before transportation (Day 60). Transport the fry/fingerlings in oxygenated plastic begs.

Before transporting, it is important that fingerlings are conditioned. The principle behind this is that they have time to empty their alimentary canal before being packed in high densities, so that the pollution of the carrying waters through excrete is reduced. Clean water from 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 in 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 1 of water

Harvesting and transportation

Density of fish (30 mm size) during transportation:

Taka budget of 0.02 ha nursery pond preparation for fingerling production.

US$1.00 = TK 38

Prepared by: MD. GOLAM AZAM KHAN

FARMER-PROVEN INTEGRATED AGRICULTURE-AQUACULTURE
A TECHNOLOGY INFORMATION KIT (IIRR-ICLARM)