Give it time maybe he's just doing it to become dominant. If it's continues you may want to separate the two. And with the payara, being sensitive and mellow, you're going to want to begin picking tankmates a bit more carefully and do research on the fish you intend to put with it because odoes can be aggressive and definitely have the capability of doing damage, like right now, mine seems to have gone on a bit of an aggression streak now that he's the largest in the tank, but nothing to where I've had to separate more of just a charge and then he backs off.