I've had this tribal blenny for a week, and I have noticed that he has a white block on his whole black body. I have seen him nip at his tail and rub/flash against the rock. He seems to not be getting along with a yellow eye kole I have(not crazy bad) but I have notice a bit of aggression. My tank is currently running on Prazipro & ick shield since we had a fish die, but think it might have been flukes. Not sure. What do y'all think? Water parameters are normal. My tank is now about 5 months.