heaps I have a variety in my tank alone- giant gourami, thick-lipped,snakeskin,moonlight,siamese fighter. i believe a fire eel can breathe air through some other method although I know it isint a anabantid. I have seen kissers and blue gouramis, but have never seen a climbing perch or a nile perch. snakeheads arent anabantids but once again they can breathe air too.