If I put a Male and female shark in a large fresh water lake what would happen to them?

Question

People say they would die because of the fresh water. Exluding people killing them would they be able to adapt and survive? Its a deep large lake with plenty of fish and mamels that live on the lake like otters, mustrats etc. So food isnt an issue just the fresh water.

Answer 1

Most marine sharks will die fairly quickly.

Sharks in Lake Nicaragua have adapted to life in freshwater, and will last much longer.

River sharks are very rare.  See the link.

http://en.wikipedia.org/wiki/Freshwater_...

Answer 2

Plenty of sharks do well in freshwater....including the bull sharks that travel more than 1000 miles up the Mississippi river in the U.S.!  And they are large, dangerous sharks.  Also, as the other person mentioned, the freshwater sharks of Lake Nicaragua (which I think might be a variety of bull shark, too).  But otherwise this group is pretty exclusively marine.

Some rays and skates inhabit pretty freshwater estuaries, too.

Answer 3

Saltwater fish, including sharks, WILL die if you put them in a freshwater environment.

The bodies of freshwater fish go to certain lengths to retain salt so their tissues can continue to function.  Dropped in salt water, that system tries just as hard to retain salt, and the much saltier water it's in will cause it to stockpile it.  The fish's cells will release water, and the fish will dehydrate to death--while immersed in water(!)

Saltwater fish have a system that removes salt from their tissues so they don't become supersaturated and die.  So when placed in a freshwater environment, their bodies continue to remove salt, and they end up with the opposite problem: not enough for their tissues to function, and they die.

I think I might have heard that saltwater fish tolerate fresh water better than the other way around, but I'm not sure about that, and I'm pretty sure that refers to more/less salt in the water, not a complete shift from ocean to lake.