I would not suggest this, as I think this is a fluke, but I have a tank with 2 guppies, a male and a female (that may not have been a good idea...) and two dwarf gouramis, and two mollies (BIG oops... they spawned EMEDIATLY) The two dwarf gouramis are both males and did not get along at all... the red one, Taco, flipped out that there was a powder blue male in his tank. Iris, the powder blue, turned out to be a major wimp, so I put Taco in another tank. Out of curiosity, I put my mild mannered Betta, Captain Zissou in with 2 guppies and a gourami... and they get along great! I have not seen Captain Zissou flare at all. He does get irratated at the mollies occasionally, as their frollicking sometimes gets in his way. He hides behind the chopsticks I put in there, and watches the other fish. Iris seems to like Captain Zissou; he hides below him as Captain fends of the frisky mollies. *thumbsups If you can, match by personality, it makes a much happier tank.