Hi thanks for the advice the only fish i have in the tank is 3 angels,3 otocinclus,and one gourami.I assumed it was the angelfish because ive seen two of them fight in a wierd way.Almost like a betta flaring but except these guys bite eachother.like you suggested i will continue to monitor them and if i see more aggression i will take the gourami out.once again thank you