My dalmation molly always swims past the other fish (especially the pop bellied molly) with his top fin all flared up, then he will put it down and swim past another fish and fluff it up. Is this his way of trying to show dominance? It is funny to watch him, it almost like he is strutting around the other fish, he is a tiny bit larger than the others.. not much though.

It sounds like a *im the top fish here* kind of thing. If its to other mles then yes its dominance and if its to females both dominance and seeing if they are read to breed.

Well I know my 2 guorami's are male and the pop bellied molly, I am not sure. I have 2 neon tetra's and 4 danio's (those are really small) -- he does it the most to the other molly, and they will butt their heads into each other.... It is funny to watch them... prancing all around... haha