saltwater fish in fresh water

Question
My question is, what happens when you put a strictly saltwater oriented fish in fresh water.  I know it will probably die, but the question is how.  I've been told it becomes bloated because it takes in water and doesn't release it. Is this true?

thanks for answering my question,

JE

Answer
Dear J. Elliott,

  Well thats an unusual question. I am not an expert about this but, I do know that fish have to expell the salt out of the water when they breathe it. So I am guessing that, that must be the main reason the will die. I have been told that if introduced to saltwater slowly, the fish might live.
  There are several species of fish that live in both fresh water & saltwater. Some at different times in their life cycle, such as the Salmon. Born in Fresh water then they go on out into the ocean for several years then back to where they were born & spawn new fish there & die. Snook and several other type of fish swim & live in Brackish water. Its a mixture of Fresh & Salt Water. If you want to check out the new menace in the North America to our Native Fish, check out the Snakefish. It might make an interesting report or paper for your science class. Good luck.