# How Do Anadromous Fish Survive?

**URL:** <https://boards.straightdope.com/t/how-do-anadromous-fish-survive/451208>\
**Category:** Factual Questions\
**Created:** [May 30, 2008, 10:58pm UTC](https://boards.straightdope.com/t/how-do-anadromous-fish-survive/451208 "2008-05-30T22:58:37Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\
**Post date:** [May 30, 2008, 10:58pm UTC](https://boards.straightdope.com/t/how-do-anadromous-fish-survive/451208/1 "2008-05-30T22:58:37Z")

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Fish that can live in both salt and fresh water are rare-can they adapt gradually to a change of water? Or will saltwater fish always die in freshwater (and vice versa)?

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**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\
**Post date:** [May 31, 2008, 4:23am UTC](https://boards.straightdope.com/t/how-do-anadromous-fish-survive/451208/2 "2008-05-31T04:23:18Z")

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You can acclimate mollies to varying levels of salinity, even to a full saltwater tank.

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**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\
**Post date:** [May 31, 2008, 4:29am UTC](https://boards.straightdope.com/t/how-do-anadromous-fish-survive/451208/3 "2008-05-31T04:29:51Z")

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Hadda go look it up.

And Atlantic salmon do not automatically die after breeding; they go back to the ocean. So they go back and forth between fresh and salt water.