Freshwater Prawns
Commercial Prawn Production
Commercial production of freshwater shrimp or prawns (Machrobrachium rosenbergii) has been the subject of research and commercial enterprise in the United States for several decades. This species is native to the tropical Indo-Pacific region. Basic production techniques were developed in the late 1950s in Malaysia, and refined in the United States, Israel, and several Asian countries. In 1984, the MSU Mississippi Agricultural and Forestry Experiment Station initiated an extensive research program to develop and evaluate management practices for the establishment of a commercial freshwater prawn industry.
Production
Pond production involves stocking nursed, juvenile prawns, followed by 4 to 6 months of growout until they are ready for harvest. Ponds should be filled with well water and fertilized about 2 to 3 weeks before they will be stocked. Juvenile prawns weighing between 0.25 to 0.4 grams are stocked when morning water temperatures consistently remain above 68 degrees F. Stocking rates range from 8,000 to 28,000 per acre.
The goal of feed management is to achieve maximum growth by providing a continuous source of nutrition as inexpensively as possible without overfeeding. Overfeeding reduces potential revenue and can lead to poor water quality. Most successful producers use a combination of organic fertilizers and pelleted forms of agricultural feeds or feedstuffs. The protein content of these products ranges from 17 to 20 percent (as is) or 20 to 20.3 percent on a dry weight basis. Feeding rates are estimated based upon water temperature and prawn biomass.
Dissolved oxygen and pH are the principal water quality variables that influence growth and survival. Aeration is vital even when stocking density and fertilization rates are low. At least 3 ppm dissolved oxygen should be maintained to achieve high growth rates. Prawns grow best at a pH of 7 to 8.5, but will still grow and survive at a pH as low as 6.5 and as high as 9.5. Well buffered water (total alkalinity between 50 to 150 ppm) is less prone to pH swings. Water with lower alkalininty and can be increased to desired levels by applying agricultural lime (CaCO3).
Harvest
Prawns should be harvested when daily water temperatures range from 62 to 68 degrees F for 4 to 5 days, or before a cold front may cause lethal water temperatures (≤ 55 degrees F) to occur. In Mississippi, this usually around the end of September. Harvest is most efficient in ponds designed for drain down into harvest basins located either within or outside the pond.
Currently, yield from most commercial enterprises in the U.S. ranges from 600 to 1,800 pounds per acre. Yield is influenced by a combination of factors such as stocking density, stocking size, duration of growout, and presence of substrate.
Marketing
Since a pond has to be drained in order to be harvested, all of the prawns must be marketed at the same time. This can be a daunting task for someone accustomed to selling small amounts of product over a longer period of time or who sells wholesale to a processor that purchases the entire amount of product.
Live prawns sell at wholesale for about $4.00 to $8.00 per pound, while final retail prices are about $10.00 to $22.00 per pound. To meet production costs, farmers must receive the upper end of this price range. This can be best accomplished by either selling to live markets or conducting pond-bank sales. Live markets sales can be challenging because prawns do not tolerate poor hauling conditions, especially when stressed. Producers marketing by pond bank sales usually chill-kill animals to ensure the best quality and facilitate transport by consumers.
Mississippi Potential
Research and on-farm demonstration projects have proven that prawn production has the potential to be a profitable enterprise in Mississippi. While the availability of juveniles remains a constraint, the major limitation to successful commercialization is the establishment of consistent marketing channels.
There are three phases of culture of the freshwater prawn - hatchery, nursery, and pond growout. If you are contemplating starting freshwater prawn production, forego, initially at least, the hatchery and nursery phase, purchasing juveniles from a supplier. If you are successful at pond growout, you could begin plans to develop a nursery, and possibly a hatchery. Production of freshwater prawns in Mississippi requires a permit from the Mississippi Department of Agriculture and Commerce.
MSU Publications & Information
Sustainable Farming of Freshwater Prawns and the Assurance of Product Quality
Culture of Freshwater Prawns in Temperate Climates
Other Freshwater Prawn Information
Pond Production of the Freshwater Prawn in Temperate Climates
https://srac.tamu.edu/serveFactSheet/191
Freshwater Prawns: Biology and Life History
https://srac.tamu.edu/serveFactSheet/132
Economics of Freshwater Prawn Farming in the United States
https://srac.tamu.edu/serveFactSheet/185
Post-Harvest Handling of Freshwater Prawns
https://srac.tamu.edu/serveFactSheet/226
Small-Scale Marketing of Aquaculture Products
https://srac.tamu.edu/serveFactSheet/64