Tropical usually refers to Freshwater tropicals; and so the answer is no, because all starfish are saltwater.
no.because it dies because of your ulgyness XD!!
Rule of thumb is to not mix tropical fish and goldfish.
Cause there is algae that grows on the side of the tank, and that's what the starfish eat.
No. The temperature variation will kill one or the other. (Too warm for cold water fish, too cold for tropical fish)
U buy tropical fish and get a background and then that is how u can do that
No! marine fish are salt water fish and tropicals are fresh water fish, this cannot be changed.
They can be in a community of other tropical fish of the same size.
no tropical fish need warm water
Provided the tank is large enough and the catfish is a tropical species there should be no problems.
No. Not in the traditional definition of the tropical tank. A tropical tank is a freshwater aquarium. Regal Tangs are saltwater fish and go in a saltwater tank (marine aquarium).
As long as they get the same food and are surounded by the same enviroument they will stay the same. But they may be confused if the tank has things moved around. But they get used to it.
why not
Probably the fish. I would not put a crab in a tank with tropical fish unless they were a LOT bigger than it was, and it was not going to grow any larger.