Not so pretty fight

I have had these two clowns with an anemone to host on each side and these little guys have been the best fish anyone could as for. They would eat from my hand, go up to the glass when i stood in front and yea. Today i see one in its far right anemone which recently split and it looks like the anemone since it split it is too small for him. The one in the far left anemone was missing, found him over the power head all chewed up. The one from the little anemone was now in his big anemone and every time it would see him come down from the power head it would fight like they were cats and dogs. I'm not sure if this is from the anemone splitting or what? But has this happened to any of you? Do you think it could be something else. Params are good, fish are fed good as well eat very well. I don't know it feels disappointing to lose a fish that has been with me for a while. :-/