Saltwater/Freshwater fish question.?

Its the ago old question followed with an age old answer... it all "depends" on the species.

Salmon are born in fresh water and quickly move to salt water. The change called smoltification occurs to obviously young fish called fry. (no you cant fry them as they are protected!). The Salmon eventually return to fresh water to spawn and then die.

The Delta smelt lives in between salty and fresh water in the California Bay Delta. Its not a good swimmer and can tolerate neither straight sea water nor complete fresh water.

Bull and Nurse sharks found in the ocean, have been known to travel up fresh water rivers where they can remain for weeks. They have also been responsible for killing unwary swimmers in the streams and rivers.

I also read that jelly fish that once were living in salt water are now living inside an extinct volcano that over thousands of years is now filled with freshwater. The jelly fish have no known predators in the fresh water and have lost the ability to sting.

So I guess it all depends upon the specie and the evolutionary process of that individual species

Most fish will die if they are put in the wrong type of water eg a saltwater fish in fresh water. There are diadromous fish such as eels and salmon that spend parts of their life cycles in saltwater and parts in freshwater.

I'd say that some certain fish would need specific salinity. Global warming is melting the polar ice caps and messing with the salinity of some seas, not to mention raising the water temperature which is very bad for some fish.

No you can NOT mix! why do people think that.

they are called saltwater and freshwater fish for a reason!

salinity needs to be at 1.021 about and thats like

perfect.between 75 and 80 degrees for saltwater.

there is brackish water fish which has low salt in the tank

and theres fish for that that some freshwater and saltwater

but remember only a few saltwater can do that.

the salinity needs to be at that level..if its too high it will

burn the fish due to the raise in the tank water. and if

its to low it will die.

No saltwater fish and freshwater fish cannot live in a different environment. Some puffer fish can tolerate different levels, but its risky. All types of fish can handle different salinitiy levels- you'd have to look at the specific fish to see what level it can handle.

Aquarium fish really cant live in different places besides where they come from. If you put a saltwater fish in a freshwater tank it will die and vice versa.

Salmon can go from fresh to salt water though...

Yes, changes in salinity will kill most water creatures. Some animals can endure the change, there are areas around deltas where the rivers run into the oceans and certain fish and water creatures survive in such a hostile environment.

A lot of species living in the sea would die if there was a significant change in the salinity of sea water.

Fish are adapted to live either in salt water seas, or fresh water lakes and rivers. There are species (Salmon and Eels for example) that live for part of their lives in both. There are also some that are adapted to living in brackish water, around estuaries for instance, where salt and fresh water meet and mix.

Noooo! absolutley not there are other fish called brackish fish that have a higher salinity level but those are special fish. Only freshwater fish need freshwater tanks and vice versa. Thats why they/scientist/marine specialists etc.. group them into catagories. Saltwater fish and freshwater fish.brackish, snails, goldfish etc..

NO

saltwater fish are called saltwater fish for a reason, same with freshwater..hence the names..

there's straight on salt water, freshwater, and brackish water.

Mollies are usually sold as freshwater, but do better in brackish, and have been kept in full on salt water tanks.

Some fish, like the mollies, can live in differant levels. It's all about acclimation.

Absolutely not! that would throw the internal fluid balance of a fish totally out of whack and cause its cells to burst like a ballon!