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Abstract
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Litopenaeus vannamei postlarvae were exposed to 0, 6, 13, and
19 mg/L total ammonia nitrogen (TAN) treatments. After
45 days, shrimp weight and length were lowest under TAN
concentrations of 13 and 19 mg/L (P ? 0.05). Maximum weight
gain was observed in control and 6 mg/L treatments. Mortality
was highest (80.55 ± 4.80%) under 19 mg/L reared in 35 ppt
salinity. Average intermolt periods of PLs exposed to 0, 6, 13,
and 19 mg/L TAN were 11.5 ± 0.7, 10.8 ± 1.3, 9.4 ± 1.0, and
8.7 ± 0.6 days under 35 ppt and 11.1 ± 0.5, 10.7 ± 0.6,
10.1 ± 0.5, and 9.5 ± 0.2 days under 45 ppt salinity. Although
TAN increased postlarvae molting frequency, its negative
effects on the shrimp growth and survival of PLs was directly
linked to its concentration and exposure duration. Higher salinity reduces the effects of ammonia and increases the survival
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