Effects of diet and water source on the nursery production of Pacific white shrimp Litopenaeus vannamei

Penaeid shrimp reared in eutrophic pond water grow significantly faster tha n shrimp in clear well water, and this growth enhancement is especially pro nounced in postlarval shrimp. The objective of this study was to determine if the nutritional benefits of pond water could supplement a lower protein feed for postlarval Pacific white shrimp Litopenaeus vannamei. Sixteen 230- L tanks were stocked with 10-d postlarvae at a density of 350 shrimp/tank. Four treatments (four replicates/treatment) were tested for 6 wk and consis ted of: 1) shrimp grown in well water and fed a commercially available 45%- protein feed (W/45); 2) shrimp grown in pond water and fed the same 45%-pro tein feed (P/45); 3) shrimp grown in well water and fed a commercially avai lable 52%-protein feed (W/ 52); and 4) shrimp grown in pond water and fed t he same 52%-protein feed (P/52). At the end of the experiment, mean weight gain (+/- SE) for shrimp in pond water (1.85 +/- 0.03 g) was significantly greater (P < 0.0001) than shrimp in well water (0.98 +/- 0.10 g). Mean weig ht gain for shrimp fed the 52%-protein feed (1.56 +/- 0.13 g) was significa ntly greater (P < 0.0001) than shrimp fed the 35%-protein feed (1.26 +/- 0. 20 g). In addition, there was a significant interaction effect between wate r source and feed (P < 0.0001). Mean weight gain for shrimp in the W/52 tre atment (1.23 +/- 0.04 g) was 68% greater than shrimp in the W/45 treatment (0.73 +/- 0.03 g). However, mean weight gain for shrimp in the P/52 treatme nt (1.90 +/- 0.03,a) was only 5% greater than shrimp in the P/45 treatment (1.80 +/- 0.04 g). These results suggest that organically rich pond water p rovides postlarval shrimp with sufficient nutrients to compensate for nutri tional deficiencies associated with a lower protein feed.