Construction and maintenance of prawn farms

1. Construction and Maintenance
of Prawn Farms
By
Balwant Singh
Dheeraj Shukla
balwantsingh1642@gmail.com

2. Requirements and Characteristics
of Prawn Farm
• A good hatchery site should also have the
following characteristics:
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.

3. Cont……
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
project.
5) A climate which will maintain water in the
optimum range of 28o -30o C without costly
environmental manipulation.
6) Access to food supplies for larvae, adults and
brooders.
7) A high level of technical and managerial skills.

4. FARM FACILITIES
• 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
prawn farming.

5. Cont…..
• 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
finance available.
• A complete hatchery design for freshwater prawns
is simple to construct and operate in sequence.

6. Fresh Water Prawn
Farming Concepts
• 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
120 days.

7. Prawn hatchery
• 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
grow-out enterprises.

8. Farming of Fresh Water Prawn
• Fresh Water Culture are depend upon following
things:
1) Location of farm
2) Farm Permits
3) Farming Strategies
4) Pond Construction
5) Crop Species & Feeding
6) Stocking
7) Management
8) Harvesting

9. Farm Location
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.

10. Farm Permits
• Construction permits from Corps of
Engineers
• Aquaculture Permits from state
• Local permits

11. Farming Strategies
• Extensive
– Large ponds
– Low stocking densities
– Little management or investment
• Semi-Intensive
– Falls in between the two extreme of intensive and
extensive
• Intensive
– Smaller ponds
– Aeration
– High stocking densities
– Feeding

12. Water quality
• Freshwater from a river, stream or lake,
rainwater, or groundwater can be used.
• Hardness (as CaCO3) should be in the range 50–
100 ppm.
• 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.

13. Water Quality for Grow out
Ponds
• Temperature: > 68F
• Salinity: 0.5 - 35 ppt
• Dissolved Oxygen: > 5 ppm
• pH: 7.0 – 8.3
• Unionized Ammonia: < 0.01 ppm
• Nitrite: < 1.0 ppm
• Nitrate: < 60 ppm

14. Pond Construction
• Ponds range in size from 1-10 acres
• 4-7 feet deep
• Gentle bottom slope
• Well maintained level

15. Pond Design
• 1 to 25 acre in size
• Silt soil
• Good water source
• Rectangular in shape

16. Pond Preparation

17. Hatchery components
• Some of the basic hatchery components and
equipment are:
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
stock holding
5) Nursery tank 5000 L for PL (optional)
………

18. Cont……
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

19. Management
• Fertilize ponds prior to stocking
• Feed good quality prawn feed
–35% protein
–3-5% bwt per day
• Provide aeration when necessary

20. Harvesting• Harvest in October month
• Drain and seine pond net
• Direct market or sell to processor
• Store after dry

21. Prawn Harvesting in River & Pond
Push nets

22. Commonly Cultured Marine Shrimp
• Penaeus merguiensis – Banana prawn
• Penaeus indicus – Indian prawn
• Penaeus japonicus - Kuruma prawn
• Penaeus duorarum – Atlantic pink shrimp
• Penaeus aztecus – Atlantic brown shrimp
• Penaeus setiferous – Atlantic white shrimp
• Litopenaeus vannamei – Pacific white shrimp
• Penaeus monodon – Black tiger prawn

23. Brood stock
• 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.

24. 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
conditions.
• The maturity stages of females and male
can be determined by external examination
of the ovary, and testis.

25. 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)

26. Hatch tank management
• Berried females ready for spawning should not be
disturbed and should be kept secluded in the
hatch tanks.
• 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
bottom-siphoning

27. FACTORS ENCOURAGING PRAWN
FARMING EXPANSION
• Compatible with agriculture
• Small farmers can practice in their own land
• No interference with mangrove or
environment
• Can be normally grown in salinity up to 8
ppt
• Large suitable areas all over the country

28. 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
better nutrition.

29. SOME CURRENT PROBLEMS
• Culture mostly dependent on rain water; no
assured perennial water supply or drainage
network.
• Available commercial feeds are either of
inadequate quality or are too expensive.
• Poor nursery practices.
• Declining wild brood-stock population due to
over-fishing.