They may be establishing their sex, being that they are smallish, I would put one of them in one of those little acrylic breeding box's{used for guppies} that you can leave in the aquarium, then they can't beat the crap out of each other, and will sort out who is going to be the male and female. It will take a few weeks but they should be ok. I am assuming you have some live rock in your tank as well as they need a place to hide after a few weeks as well. Imo if you don't do something you will be minus one clownfish soon. Good Luck
