tharbin
2500 Club Member
Welcome to R2R! Clownfish are very territorial and as @vetteguy53081 said they all start as males. The dominate of the two will transition to a female eventually, if the less-dominate one survives that long. They will definitely fight even after one transitions just to retain the hierarchy. The question is not will they fight, yes they will, the question is will one of them kill the other. If it looks like it is heading in that direction you will need to catch out the dominate one and put it in an isolation box for a period of time. Usually after a few days or maybe a little more you won't see the aggressive one reacting every time the other approaches. A few days after that you can try to reintroduce the aggressor but be prepared to catch it out again. Hopefully they will fight for dominance but not to the point of inflicting real damage, but be warned, clownfish are very territorial and are quite often the tank bully. Sometimes they even bite their keeper.
