Stocking Strategies for Production of \u3ci\u3eLitopenaeus vannamei\u3c/i\u3e (Boone) in Amended Freshwater in Inland Ponds

The performance of the Pacific white shrimp Litopenaeus vannamei (Boone) under various stocking strategies was evaluated in earthen ponds filled with freshwater amended with major ions. Six 0.1-ha earthen ponds located in Pine Bluff, Arkansas, USA, were filled with freshwater in 2003 and 2004, and potassium magnesium sulfate added to provide 50 mg K+ L-1 and stock salt added to provide 0.5 g L-1 salinity. In 2003, three ponds either were stocked with PL15 shrimp (39 PL m-2) for 125 d of grow out or with PL25 shrimp for a 55-d (23 PL m-2) followed by a 65-d (28 PL m-2) grow-out period. In 2004, ponds were stocked with 7, 13, or 30 PL15 m-2 for 134 d of grow out. Salinity averaged 0.7 g L-1 during both years, and concentration of SO4-2, K+, Ca2+, and Mg2+ was higher, and Na+ and Cl- was lower in amended pond water than in seawater at 0.7 g L-1 salinity. Potassium concentration in amended water was 52-61% of the target concentration. Shrimp yields ranged from 3,449 kg ha-1 in 2003 to 4,966 kg ha-1 in 2004 in ponds stocked with 30-39 PL15 m-2 for a 125-134-d culture period. At harvest, mean individual weight ranged from 17.1-19.3 g shrimp-1. In ponds stocked with PL25 shrimp, yields averaged 988 and 2,462 kg ha-1 for the 1st and 2nd grow out periods, respectively. Gross shrimp yield in 2004 increased linearly from 1,379 – 4,966 kg ha-1 with increased stocking rate. These experiments demonstrated that L. vannamei can be grown successfully in freshwater supplemented with major ions to a final salinity of 0.7 g L-1