We have a molly that was the alpha male for several months until recently when a smaller molly male took the dominant role. Ever since then his health has seemed suspect. I am not sure if the change started to happen before his health turned and the other male sensed the weakness or if being constantly chasedd down and nipped at has made him weary. We often find him hiding out behind the heater or something to get out of sight of the other male but will sometimes venture out and will seem OK but nervous. I don't see any sores or marks on him, the only thing I have noticed is his irridescent blue color on his dorsal fin is no longer there but figured that could be due to the stress of being chased. He is the biggest molly we have and I am just wondering if he is getting to the end of the road age wise. How do fish tend to act when they get old? We are just a bit perplexed by this since the original alpha male is about twice the size and can typically out swim the new guy, so we aren't sure why he doesn't just fight back.