Common examples:
* Salmon: They are born in freshwater rivers, migrate to the ocean to grow, and return to freshwater to spawn.
* Eels: Many eels spend their adult lives in saltwater but migrate to freshwater rivers to spawn.
* Flounder: Some flounder species can live in both freshwater and saltwater environments.
* Mullet: These fish are common in coastal areas and can tolerate both freshwater and saltwater.
* Tilapia: This popular food fish can adapt to a wide range of salinity levels.
* Striped Bass: They can live in both freshwater and saltwater, though they prefer brackish water (a mixture of fresh and salt).
Less common examples:
* Bull Sharks: They can live in rivers and estuaries, but also in the ocean.
* Tarpon: These large fish can live in both freshwater and saltwater.
It's important to note:
* Not all fish can survive in both freshwater and saltwater. Some fish are stenohaline, meaning they can only live in one type of water.
* The ability to adapt to different salinities is not always the same for different species. Some species may be more tolerant of changes in salinity than others.
* Euryhaline fish have special adaptations that allow them to survive in different salinities. These adaptations include the ability to regulate the amount of salt in their bodies and to adjust their kidney function.
If you're interested in learning more about euryhaline fish, you can search for information online or consult a biology textbook.