Can you feed freshwater fish salt water pellets?

Freshwater fish cannot adapt to saltwater because their bodies are not designed to handle the high salt concentration. If a freshwater fish is placed in saltwater, it will drink the water in an attempt to maintain its internal water balance, but the high salt concentration will disrupt the fish's electrolyte balance and metabolism, leading to death within a few hours. Conversely, saltwater fish cannot survive in freshwater because their bodies are adapted to the high salt concentration of seawater and they cannot osmoregulate in the lower salinity of freshwater. Therefore, it is important to keep freshwater and saltwater fish in their appropriate habitats and to never mix them.