Macrobrachium rosenbergii
The freshwater shrimp, or more properly, freshwater prawn, is a member of a large group of freshwater crustaceans found in many parts of the world. There are several species found native to the U.S., but most aquaculture efforts are concentrated on the Giant Malaysian Prawn (Macrobrachium rosenbergii) which is a native of southern Asia. Culture efforts in the U.S. were initiated in Hawaii in the 1960s, South Carolina in the 1970s, and Mississippi in the 1980s. Despite these efforts, substantial concentrated production of this species has not developed. Large scale production has been hindered by relatively low production rates, size variability at harvest, and a relatively demanding process for producing seedstock. Over the past five years interest in production of this animal has again increased due to an increasing demand for shrimp products, reduced supplies of shrimp (especially large sizes) due to serious disease problems in saltwater shrimp production, and increases in production rates for prawns based on new management and production practices. Other factors producing increased interest in production include identified markets for live and fresh prawns in inland locations, the growing trend among consumers wanting to know of how their food was produced, and the discovery that prawns actually grow more rapidly at cooler temperatures. Seedstock production for prawns normally begins with selection of broodstock at the harvest of production ponds in the fall. The number of females is based on anticipated production needs. Broods must be overwintered in tanks at greater than or equal to 70º. Volume and added substrate in holding tanks should allow each brooder approximately two square feet of surface area. Broods should be fed a high quality marine shrimp diet or sinking salmonid pellet. Either should be supplemented with fish flesh and beef liver so that the females can store the proper nutrients in the egg yolks for the larvae to live on after hatching. In Kentucky, production ponds are stocked in late May-early June with what are known as 60 day nursed juveniles (0.3-0.5 gram average weight). That is they have been grown for 60 days in freshwater after completing 30 days of larval development in brackish (salty) water. This means prawns should be hatched from mid-February to mid-March to allow sufficient nursery time prior to pond stocking. Nursery tanks are normally much larger than larval tanks as stocking rates are reduced from approximately 200 per gallon in the larval tanks to 20 per gallon in the nursery tanks. These tanks must also be provided with mesh substrate structures sufficient to produce 40 post larvae per square foot density. In the nursery phase, water temperatures are maintained at 78-82ºF and the prawns are fed trout starter feeds at a declining percentage of body weight. READ OR PRINT the 43-page prawn manual FREE (PDF document requires Acrobat). Doesn't include cover photo, and some graphics slightly altered. TO ORDER a manual. Cost is $10.00 ($15 for international order). Make check or money order to KSU Aquaculture, and send to: KSU Aquaculture Manual, 103 Athletic Road, Frankfort, Kentucky, 40601 USA |