Survival, growth, and oxygen consumption rates of Farfantepenaeus paulensis postlarvae (PL) were examined at different salinities. Initially, PL 15 maintained at 30‰ salinity were gradually acclimated to 2, 5, 10, 20, and 30‰ over 5 days. Afterwards, survival, growth, and oxygen consumption rates of shrimp reared at these salinities were determined over a 42-day experimental period. Lower wet weight and cephalotorax length, and higher mortality rates were observed in shrimp reared at 2‰ salinity, especially when compared with those reared at 10‰ salinity (P < 0.05). In the range of 5‰ to 30‰ salinity, growth was optimized at 10‰ salinity, although this response was not significant. Salinity affected the oxygen consumption rates of F. paulensis postlarvae. At the beginning of the growth trial, oxygen consumption rate was markedly lower at 2‰ salinity than at 10‰ or 30‰ salinity (P < 0.05). This response was probably associated with a metabolic depression that preceded the shrimp death. Thereafter, oxygen consumption at 2‰ salinity showed a nonsignificant increase due to a higher variability of measurements probably associated with a better performance of surviving shrimp, which were tolerant to low salinity levels. At the intermediate salinities (5‰-20‰), oxygen consumption was higher at 10‰ salinity. At the end of the experiment, oxygen consumption reached similar and low levels irrespective of the salinity level. Oxygen consumption rate of shrimp reared at 30‰ salinity was constant and close to 5-μL mg dry weight-1 hr -1 throughout the experiment.