Note
The effect of three essential osmoregulatory ions on the short-term survival of Pacific white shrimp Litopellaells vannamei in freshwater (<I ppt total ion concentration) was examined in several experiments. Shrimp postlarvae (PL-18 and -28) were acclimated from seawater (32 ppt) to freshwater over 48 h and held for an additional 24 h before being placed in treatment solutions.