Join Date: Oct 2010
Location: Victoria, Australia
I think redirected aggression could be a possible cause. Like when a reactive dog sees another dog, is unable to get to it, and redirects that aggression onto its owner.
I also wonder if there's an element of OCD with some fish. Because some males will bite their fins once or twice, and then never again, whereas, for some it becomes almost a compulsion. Even if the environment is changed, and the fins are bitten down to a length where they no longer impede swimming, the fish continues to bite them. I had a male that would constantly bite whatever fins he could reach, down to bleeding nubs. It was very distressing as an owner to watch.
It would be interesting to see if genetics plays a role. For example, I've always wondered if artificially raising the eggs of egg-eating males, simply perpetuates this behaviour in future generations.