What saltwater animals can survive in freshwater?
Do you mean fish? Unfortunately, no marine/saltwater fish will survive in fresh water. Some fish will be able to survive longer than others with the salt content in freshwater. In the end, any of them will die. Some wild fish are capable going from salt to fresh for a while, but eventually they need to return to their saltwater habitat to survive. There was a whale that got stuck in the Sacramento River last year and survived quite awhile (over a week) before rescuers got it back to the sea. Unlike fish, sea otters are quite capable of living in freshwater. They do not get their oxygen through the water, making it very easy for them to live in freshwater.
