What happens if you put a freshwater fish in the sea, and if you put a saltwater fish in freshwater ? ?

Question

What happens if you put a freshwater fish in the sea, and if you put a saltwater fish in freshwater ? ?

Answer 1

Some fish can go between the two (salmon), but they have to change in order to do that, and that takes some time. Usually what will happen is that the cell in the saltwater fish will swell up and rupture, and the cells in the freshwater fish will shrivel, and both will die.

Answer 2

They'll die

Answer 3

they die

Answer 4

and what if you stuck you on mars. like the fish, you'd die.  

Answer 5

it just ain't gonna work there chief

Answer 6

Because of the process called osmosis they would die.  Since the body and flesh of a fresh water fish has evolved to be in fresh water, if you put it in salt water, the salt would draw the moisture out of its body and the salt content of its body would get higher, so it would die.

If you put a saltwater fish in fresh water, the salt within its body would draw too much fresh water in, and its body salt would leach out into the fresh water, and then it would die.

The process of evolution has adapted these two types of fish to live in their respective environments.  If you change that, it will kill them.  There are some fish and sharks that HAVE adapted from one type of water to the other, but it takes millions of years for this to happen.  There are some fresh water lakes that used to be connected to the ocean, but through time the land has closed them off from the sea and they very slowly became fresh and the fish within them changed from saltwater fish to fresh water fish.  A lake in Thailand has done exactly that and is filled with Jellyfish that used to live in the ocean.

The only exception to this rule is Salmon, which migrate from fresh water to salt and back to fresh to lay their eggs.  I don't believe even scientists know how their bodies can handle this.