Because they constantly drink saltwater and excrete salt via the gills.
dont you mean saltwater fish?
because saltwater fish must be live in saltwater
It would dehydrate and most likely die.
saltwater
They are Saltwater fish.
Saltwater fish are hypoosmotic.
Saltwater fish live in the saltwater seas and oceans around the world.
A saltwater fish tank can be half freshwater and all of the saltwater fish will live but not for very long.
Because saltwater fish can only breathe in saltwater (as in the ocean) and freshwater fish can only breathe in freshwater (as in tap water.)
Well, there are 2 types of fish, saltwater fish, and freshwater fish. Only put in saltwater if you own a saltwater fish. Note: Saltwater fish could live safely in freshwater, but freshwater fish will suffocate in saltwater.
You dehydrate.
you dehydrate