I had a handful of Australian Rainbows in a tank with 2 opaline gouramis, 2 gold gouramis and a blue gouramie....there were other fish but that's irrelevant. Eventually only 1 rainbow fish was still living. He got big and in body shape and size resembles the gouramis. Being they are schooling fish he gravitated towards he gouramis when there were no other rainbows left. I didn't buy any fish for awhile because I had plans to set up a bigger tank. I did...I have a 125 community tank set up now, added new fish. I bought more Australian rainbows and at first the one I still had got excited and was swimming with them. But then he went back to the gouramis. I notice 2 of them seem to be hovering down by the sand a lot lately. I figured its because they're in the breeding process and that seems to be true based on what I've read. The curious thing is the Australian rainbow stays near the gold gourami like it's his mate. He hovers around her and even tends to keep other fish away from her. I've never seen anything like this and it's bugging me out. Is there a close relation in the 2 species?