If I brought a fish from a sea and put it in a lake, would it survive ?

Not likely. Even if you put it in an fish tank, matched all of the conditions of the sea somehow, it probably wouldn't survive... this is mainly due to the perfect conditions at sea.

Hi, pmh383388!

That would also depend on whether the fish was a salt water or freshwater fish and whether conditions were relatively the same where it was placed.

If it was placed in some controlled environment in the lake, where the conditions of the sea were duplicated, then it's possible that it might survive.

But, if the conditions weren't the same, then I would agree that it's not likely that it would survive.

I assume that you are asking about moving from salt water to fresh water. Very few fish can survive in both fresh water and salt water. The few species who can live in both (like salmon) must take time to adapt when moving between the two environments. Here is an explanation:

Freshwater fish in salt water

I have known of salt water fish that have been adapted to well water.

When I was younger I remember many of my friends used to have ocean fish (small ones) in their wells,and they do survive in the well for quite a long time.

Maybe well water where I am has something in it that is common to salt water as we are so close to the ocean.
Maybe a lake close to the ocean may have something in them that could possibly aid in salt water fish to survive in a lake?

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I did an experiment on one fish, or rather two types that is available where I am. One failed but the other succeeded. The project consisted to acclimatising sea water fishes into fresh water and was done by transferring the fishes from sea water to fresh water while gradually decreasing the salt comcentration of the water.