"An example of this phenomenon can be observed when water moves from an area with a high salt concentration to an area with a lower salt concentration. This movement of water, caused by differences in concentration, is known as diffusion."

To address this issue, fish are equipped with kidneys and gills that play a role in filtering salt from seawater, allowing fish to consume that water without risk. In addition, a layer of chloride cells in the fish's body is responsible for excreting excess salt, maintaining internal balance.