Construction and Maintenance
of Prawn Farms
Requirements and Characteristics
of Prawn Farm
• A good hatchery site should also have the
1) A secure power supply which is not subject to
lengthy power outages. An on-site emergency
generator is essential for any hatchery where the
scale of investment warrants it.
2) Good all-weather road access for incoming
materials and outgoing post-larvae and prawns.
3) Access to professional biological assistance from
government or other sources.
4) Land, of an area appropriate to the scale of the
hatchery, with good access to seawater and
freshwater supplies. The cost of pumping water
supplies to a site elevated high above sea level is
an important factor in the economics of the
5) A climate which will maintain water in the
optimum range of 28o -30o C without costly
6) Access to food supplies for larvae, adults and
7) A high level of technical and managerial skills.
• A freshwater prawn farm is very similar to a
freshwater fish farm.
• Freshwater prawns are stocked into concrete and
earthen reservoirs, ponds, irrigation ditches,
cages, pens and into natural waters.
• Cage and pen culture is experimental, while the
production from irrigation ditches is low; stocking
into natural waters and reservoirs is not strictly
• Hatchery design will depend on the scale of
production desired, the characteristics of the site
(such as topography, climate, etc.), the type of
building materials obtainable locally and the
• A complete hatchery design for freshwater prawns
is simple to construct and operate in sequence.
Fresh Water Prawn
• Fresh Water Prawn Culture are grown in earthen
ponds located in coastal areas of countries with
tropical and subtropical climates.
• Ponds are filled with freshwater, Prawn is
reproduced and raised in captivity are stocked
into the ponds and are ready for harvest in 90 to
• The hatchery building is usually associated with
the nursery tanks and grow-out ponds in terms
of water supply and other requirements.
• A freshwater prawn hatchery produces PL for
growing out in ponds and for sale to other prawn
Farming of Fresh Water Prawn
• Fresh Water Culture are depend upon following
1) Location of farm
2) Farm Permits
3) Farming Strategies
4) Pond Construction
5) Crop Species & Feeding
1) A study of the potential market for the product
and careful selection of suitable sites for prawn
culture, whether it be for the larval (hatchery)
or grow-out phases, is an essential prerequisite
for successful farming.
2) Farm constructed near of fresh water body.
3) Road access, power supply, communication
facilities and emergency generator are all
essential components to run the equipment and
operating systems in the hatchery.
• Construction permits from Corps of
• Aquaculture Permits from state
• Local permits
– Large ponds
– Low stocking densities
– Little management or investment
– Falls in between the two extreme of intensive and
– Smaller ponds
– High stocking densities
• Freshwater from a river, stream or lake,
rainwater, or groundwater can be used.
• Hardness (as CaCO3) should be in the range 50–
• Seawater is needed to mix with the freshwater
to produce brackish water for the larvae.
• The seawater is disinfected with 10 ppm of
calcium hypochlorite and stored for at least a
week before use.
• Some of the basic hatchery components and
1) Building to house the larval rearing space
2) Hatch tanks 1000 L
3) Larval rearing tanks (LRTs)
4) Holding tanks 1000 L for PL, also used for brood
5) Nursery tank 5000 L for PL (optional)
6) Freshwater storage tank
7) Saltwater storage tank
8) Mixed water storage tank
9) Water pump management
10) Plastic buckets, basins, containers
11) Equipment for packing and transport of PL
12) Feed and chemicals
13) Ponds (200–400 m2) for rearing and
maintaining adult prawns for breeding
• Fertilize ponds prior to stocking
• Feed good quality prawn feed
–3-5% bwt per day
• Provide aeration when necessary
Harvesting• Harvest in October month
• Drain and seine pond net
• Direct market or sell to processor
• Store after dry
• The adult male and female prawns chosen for
breeding are called brood stock.
• On average, 500–1000 prawns (male and female)
need to be kept as brood stock.
• Berried females 10–12 cm long usually carry
about 10,000–30,000 eggs each and 40 g females,
35 g males.
• Brood stock are usually reared in ponds, starting
with an initial stocking density of 4–5 PL/m2. of
pond area and reducing to 2/m2 at adult size.
Growth to maturity
• The PL grow to maturity within 4–7 months
in freshwater ponds.
• The PL grow to maturity is depending on
temperature, food and environmental
• The maturity stages of females and male
can be determined by external examination
of the ovary, and testis.
Feeding brood stock
• An example of a pellet feed formulated for brood
stock feeding should roughly consist of:
1)Protein - 40%
2)Fat - 10%
3)Carbohydrate - 33%
4)Ash - 09%
5)Fiber - 08%
6)Gross energy - 04.3 kcal/g (18 kJ/g)
Hatch tank management
• Berried females ready for spawning should not be
disturbed and should be kept secluded in the
• Start with 500 L freshwater in a 1000 L hatch tank,
and stock a maximum of 3–4 berried females.
• Keep the temperature at 25°–30°C and pH 7.0–7.3
until the eggs hatch.
• Tank water should be kept clean and free of dirt
and debris through regular water changes and
FACTORS ENCOURAGING PRAWN
• Compatible with agriculture
• Small farmers can practice in their own land
• No interference with mangrove or
• Can be normally grown in salinity up to 8
• Large suitable areas all over the country
PRAWN FARMING REDUCING POVERTY
More than 80% of the farms less an acre
and handled by small farmers.
Large numbers of mono-crop low-yielding
paddies now converted into farms
producing high priced prawn and fish in
rotation with paddy .
Pond embankments grow vegetables and
fruits fetching extra income and providing
SOME CURRENT PROBLEMS
• Culture mostly dependent on rain water; no
assured perennial water supply or drainage
• Available commercial feeds are either of
inadequate quality or are too expensive.
• Poor nursery practices.
• Declining wild brood-stock population due to