Mollys (Poecilia sp.) are usually regarded (and kept as) fresh water fish but they actually come from brackish water originally. With slow and carefull conversion they can be kept in fresh or salt water environments.
Most pet stores that sell fish also sell fresh and salt water fish. Read up and learn about salt water tanks because they are different to take care of than a fresh water tank.
Fresh and salt water are very different for one key reason, fresh water doesn't contain salt and salt water obviously does. There are different flora and fauna in fresh and salt water for this reason.
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.
on fresh salt water
Salt water is water that has salt in it and it is found in oceans. Fresh water does not have salt and is found in rivers and lakes.
there is salt in salt water and little salt in fresh water
salt water
Salt water is basically just fresh water with salt mixed in.
Salt water is basically just fresh water with salt mixed in.
There was salt water but they have replaced it with fresh water.
Salt water contain salt, fresh water is practically pure.
Peru has both Fresh and Salt water. Salt Water in the ocean and Fresh in lakes, streams, and on the mountains.