If you own a Dovii couple, then I have a strange, interesting suggestion to prevent the male from attacking the female. Here's my idea-I'm thinking that you can build a "mannequin" of a fish, and paint it or something to look like another cichlid, perhaps another male Dovii, and simply put it in the tank. What I'm thinking is that the real male will take out all of his aggression on the "mannequin", or "fishequin" in this case, and that way you can minimize, or totally prevent, aggression towards the female-naturally, I'm thinking you can try this with any large, aggressive cichlid couple. Do you think that would work? Would anyone be willing to test this idea out?