Originally posted by Jim Sachs
I've never seen Siamese Fighting Fish mixed in with tropicals.
The pet store I worked at used to do this. Of course they did a lot of things that were pretty stupid, but this usually worked out fine. Almost all non-large-and-aggressive tropicals got along with the bettas; a few did like to nip their long flowing fins, but the same goes for angels. Some bettas would do the intimidation display they do to other males, puffing out the gill covers and charging at them. Especially if there were few other fish in the tank and they thought they could dominate the place. I never saw a betta actually attack a non-betta though.