Fish cells, like all cells, have semi-permeable membranes. eventually, the concentration of "stuff" on either side of them will even out. a fish that lives in salt water will have somewhat salty water inside itself. put it in the freshwater, and the freshwater will, through osmosis, enter the fish, causing its cells to swell, and the fish will die. what will happen to a freshwater fish in the ocean? be sure to include what type of solution the fish is in, the movement of water and why the water moved the direction it moved in your complete meaningful response.