Whoa, I wouldn't think a clown can leave a mark like that. Having an attack fish really makes working in a tank stressful. You always have to be on your guard. My niger trigger has been a nightmare for a long time. He bit me right in the middle of the forearm and on my tricep a few days ago. He used to just go after my hand and fingers, now its my whole arm. Each time he bites, it leaves four puncture wounds because he has four fangs.