Some fish live in salt water because they just do. Some fish live in water because they were put in water. If you get a fish at home you can put it in salt or water. It also depends on there skin because the fish can have very sensitive skin and can only touch a certain kind of water
salt water crocodiles do, and can go from fresh to salt water at will.
some star fish live in salt water
some fish live in salt water some in fresh water it all depends on the kind of fish they could live in the ocean or in the lake or in the stream or in the pond or you could have one as a pet.
Saltwater fish have the same problem in reverse. For saltwater fish, the sea water contains a much higher concentration than what is in their bodies. As a result, salt leaks in and the fish has to use its kidneys and ion pumps to excrete extra salt.
Some do- salmon spawn in fresh water but live mostly in the ocean. Most fish live in either one or the other, not both.
Flounders are Saltwater Fish, some can be kept temporarily in brackish water.
Simple You mix some rock salt in tank
Saltwater fish require salt water, and fresh water fish need fresh water, you can't mix them, or the fish will die. You need to look at each individual fishes needs as to what temp they need their water to be. There are some saltwater fish that can survive in fresh water, but it is not healthy for them.
Not ALL fish do live in Salt water. There are plenty of "Fresh water" fish around....Wikipedia states that 41% of all known species of fish are found in freshwater. SO that means that ALL the rest are found in salt water.
make it yourself by adding some salt to water!
Whales are one of the animals that can only live in salt water. Some others that only live in salt water include, salt water crocodiles, dolphins, and some types of turtles.
Some beetles can and do live in salt water, such as the salt creek tiger