No they cannot, its why they're so called.
it denpents were the fish is from the ocean or fresh water lakes
fresh water fish are fish that live in fresh water fresh water is what you would get out of the tap at home as aposed to salt water witch contains salt
salmon
Well it depends on the fish. If it is a fresh water fish then it lives in fresh water, salt water fish live in salt water.
Mosquito fishes are fresh water fishes.
salmon
Fishes' gills prevent salt from going into the fishes insides. when a fish opens it's mouth all of the water with the salt is pushed out
If the fish are fresh water fish the kidneys would not work. The fish would die.
Moray Eels are Marine water fishes So in other words, they are salt water fishes
I think you mean tap water. Tap water or pipe water as it is sometimes called sometimes has in too much chlorine. But tropical fish are still fresh water fishes. What I have heard some people do is before they introduce their pet fishes to a aquarium they fill the aquarium and leave the water for 3 days to a week and then add the fishes. This is because I think I was told it reduces the chlorine content in the water making it safer for the fish. But if you are referring to tropical fishes as fish that live in the sea. Well sea water fishes cannot live in water because sea water is not their natural habitat. The fresh water does not have in the essential components for the sea water fish to survive in fresh water. Fresh water fish cannot live in the ocean or sea either this is because the pH of the water will kill fresh water fishes. But they are brackish water fishes which can live in water that has more salinity than fresh water, but not as much as seawater.
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.
Most sea fish have sharp teeth and most river fish have no teeth