Those are the bite marks from the male.
So i finally moved them to the pond. It definitely was a challenge to move the female as she is close to 18". I have to buy a wide but low container to fit her in there and lift her out of the small opening. Hope it doesn't effect her pregnancy. In addition, i just bought another 10" F marble ray. Should i start to separate the pregnant ray from the other two rays? What is a good source of food for an expecting mothers?