I have no idea i got this question in science today though
Eel?
Based on the information provided, the creature you are describing is likely a salmon. Salmon are known for their ability to live in both fresh water and salt water, making them anadromous fish. They start their lives in freshwater rivers or streams, migrate to the ocean to grow and mature, and then return to the rivers or streams where they were born to lay their eggs. This incredible journey is known as salmon migration.
