clown fish are fighting

hi i am new to this hobby and i have a concerning question about my clownfish, they are around the same size one is lighter in orange color and the other is darker orange, the lighter one i got on 5/10/2016 and the darker one i got on 5/15/2016. when the second clownfish was introduced to the tank they seem to be friendly to each other and swim together for a little but now they fight all the time to the point that the lighter one now hides behind the filter. today i just noticed while looking at them that the lighter one seems to be scarred on the mouth and has a small red streak across from what can be considered its lip. since i saw that i have now placed the lighter colored clown inside a breeder net , is there anything i can do to try and pair or help them or will i have to return one of them to the LFS? they are both around the same size and i got them 5 days apart from two different stores. :(