Female molly and Female Swordtail. I just added the guppy, and they seem to be doing fine, the other fish are kinda going up to him every once in a while, but aren't nipping him or anything. Oh and about the Tetra thing, I got those when I first got my tank and come to find out they were the ones that had been injected with dye to make them colorful. I was so mad I went back to the store and went off on the manager, and she still wouldn't take them back. I figured if I got more to add to it, the tank would be overstocked so i have refrained. With my current stocking do you still think it would be ok to get a couple more to go with them? Thanks for the help