Shrimp survival rate at 3.0‰ was si

Shrimp survival rate at 3.0‰ was significantly
lower than that of other two groups. However, hepatosomatic index and condition factor were not significantly affected by the
ambient salinity. Shrimp body protein and ash content were not affected significantly by salinity, while body moisture increased at
high salinity, and crude lipid in shrimps was lowest at 32.0‰. After being exposed to the above three salinities for 30 d prior to the
test, shrimp oxygen consumption and respiratory quotient of the shrimps at 3.0‰were significantly higher than those of shrimps at
medium and high salinities, while salinity did not significantly affect CO2 production. When juvenile L. vannamei were exposed to
seven ammonia-N concentrations (0, 4.00, 6.67, 9.33, 12.00, 14.67, and 17.33 mg l−1) at the three above salinities to which
shrimps had been separately acclimated for 10 d at pH 8.30 and 29±0.5 °C, shrimps at 3‰ were the most susceptible to ambient
ammonia-N, and the 96 h LC50 with 95% confidence limit to ambient ammonia-N was 9.33 (8.39–10.37) mg l−1. This study
suggests that L. vannamei could adapt to a wide range of salinity, but the animals would be more susceptible to ammonia toxicity
and spend more energy to compensate the cost for osmoregulation at low salinity.