Why can't salt water fish live in fresh water?

Answer 1

Saltwater Fish are evolved to deal with water constantly rushing out of their bodies. The salt in the surrounding water exerts what is called osmotic pressure on the fish. Thus saltwater fish have evolved to be constantly drinking water and excreting salts. When you put a saltwater fish into freshwater, it continues to drink heavily and excreet salt. Thus the fish quickly loses too much salt, and its body begins to react accordingly; nervous impulses are unable to travel, and the fish's CNS shuts down, causing it to die.

There are however many saltwater fish that are able to travel into freshwater, as they have adaptations to change their behavour and Biology radically. Pacific salmon are a perfect example of this, and they are called anadromous fish. Also many species have evolved to live in brackish waters, an intermediate between salt and fresh, and can usually tolerate larger differences salinity.

Answer 2

They're not made for saltwater because if you put one in saltwater, the salt gets stuck in their gills and eventually they swallow it and choke. So they would die.

Answer 3

fresh water fish r meant for fresh water and since sea water has salt in it... they can not live in it . PS. no animal on land can drink salt water straight out of the ocean

Answer 4

because fresh water contain less salt