Disc Damage?

Alright, I have 2 females and 1 male together. 1 female is 10" and the other is 9". The male is about 7". I thought my Arowana had been nipping the disc of my larger female but the Aro is now gone and the damage continues. I see him going for the larger female when the lights are on and when the lights are out she stays against the front glass to get a break I assume. It seems he is not interested in the smaller female. It also seems just like nipping and not a full on mounting attempt.

I do not believe the damage is breeding related due to the size of them but I hope I am wrong. My questions are.......

If the damage is due to possible breeding attempts, how long does the male pursue?

Does this happen consistantly till the deed is done or does it come in waves?

If the damage is not due to breeding attempts, will he eventually stop or will I have to seperate them?

Is aggression like this common if not breeding related?

Thanks in advance.

I don't know what rolled looks like. They're pretty fat.

EDIT: After some searches, they are rolled for sure.

So will he torment her till he gets the job done or is this a continuous thing? Does this pursuit come and go?

So do I separate till she heals up or do I just let them be? What do you guys w/ proven breeders do?

Well, I separated them. I guess I'll give her time to heal and try to mix them again. Any other suggestions?