POND REARING TRIALS WITH MALAYSIAN PRAWNS, Macrobrachium rosenbergii, BY PRIVATE GROWERS IN SOUTH CAROLINAl 19811

During 1981, pond culture trials with prawns, Macrobrachium rosenbergii, were conducted with 7 private farmers in order to obtain information on the potential for prawn farming in South Carolina. Some farmers were able to control water quality while other farmers had little or no ability to modify pond environmental conditions. Seed stock, feed, management, and harvesting assistance were provided by research personnel, while daily monitoring of pond conditions and feeding were the responsibility of the farmers. Eight ponds (size range 0.04-0.41 ha) were stocked with small juvenile prawns (mean weight 0.29 g) at densities of 4.3/m2 (43,000/ha) or 6.5/m2 (65,000/ha). An additional pond, containing hung webbing to increase habitat area, was used in a high density rearing trial and stocked at a density of 19.5/m2. Growing periods ranged from 125 to 173 days during which time most farmers encountered some serious problems (predators, competitors, low dissolved oxygen levels, etc.). In the lower density trials (4.3 and 6.5/m2) production averaged 573 kg/ha (range 155–900 kg/ha) while survival averaged 44.2% (range 13.4–67.9%). Feed conversions ranged from 1.84 to 7.40 and averaged 3.34. The high density trial resulted in a production rate of 1,902 kg/ha, a survival rate of 51.2%, and a feed conversion of 2.4. Disposition of the prawn crops included: 1) direct sales to customers; 2) marketing through a farmer-owned restaurant; and 3) retention of a portion or all of the production to substitute for the purchase of marine shrimp. Direct sales to consumers offers a number of advantages and may be the most suitable market for the predicted near-term level of production.