Bristlenose catfish (Ancistrus dolichopterus).

Question
My 18 month old male has bred several times with successive, however, he has now killed three of his offsprings, two of whom were young females and now severely dammaged his mate. He sucks at them even taking large chunks off their bodies including heads and was observed to even eat most of one young victim. What do you consider is the problem

Answer
It is rather common for most fish to get hostile toward their young and even thier mates. For example, the guppy, a peaceful fish will eat its young and it very brutal towards its mate. I would suggest seperating the babies and the mate if you plan on continuing to breed. This is a must unless you do not plan to have much success in the young and mate living long. If you do not seperate them the actions will continue. Hope this helps.