Pond-to-pond variability in post-larval shrimp, Litopenaeus vannamei, survival and growth in inland low-salinity waters of west Alabama

Despite the recent success of Alabama shrimp farmers in culturing the Pacific white shrimp, Litopenaeus vannamei , in inland low-salinity waters there is large variability in growth and survival among ponds. Farmers suspect that high mortality occurs during the first weeks of culture following stocking of postlarvae (PL). In order to determine the effect of pond ionic composition on PL growth and survival, three trials were carried out at a shrimp farm. Trials 1 and 2 evaluated PL growth and survival over 21- and 28-day periods, respectively, using static water from different production ponds. Trial 3 evaluated growth and survival over 7, 14, 21 and 28 days using water from one production pond. Results suggest that initial mortality (8–10%) is attributed to the acclimation process and occurs immediately following stocking. Pond-to-pond variations in ionic profiles could be a contributing factor but are not likely the major reason for variable 'survival'. Mortalities after stocking appear to occur quickly as there were no differences in survival from 7 to 28 days post stock. Variable survival is likely due to a combination of reasons including environmental factors, but is largely due to poor handling of PL and stocking errors that produce perceived reductions in survival.