Hey guys, apologies for the long post but I can’t find anything on these white bullseye markings on multiple tangs. I have 2 tanks, both have been running 2 years just about. Mixed reef and the fish are thriving. Parameters are ideal. Recently I purchased a convict tang for my bigger 165 gallon waterbox. I had a convict tang in there for over a year, the healthiest fish I ever owned. It could eat 24 hours a day if it wanted and would swim into my hand to play. I thought since they are known to school with other convicts I wanted to add another. As soon as I added the larger Convict, my other Convict ruthlessly attacked him. They chased eachother nonstop. I put up a tank divider where they can view each other and it stopped. 3 days later I removed it but they went back at it. I removed the new convict and put him in my other 100 gallon waterbox for a temporary home. He died over night. Then 5 hours later my other convict who I owned for over a year died in my 165. They both had bruise like circles on their bodies. Now my two other tangs (Vlamigii and Tomini) both have this large white circle with a dot in the middle. It looks like a white bullseye. These are extremely healthy fish that ruled the tank and now my vlamingii is not as active and swimming low to the ground. They eat, but slower than usual. Are these battle wounds from when I put the new convict in for a temporary home? Did they fight in the night? No aggression that I inspected that night before he died the following morning. I’m very confused, these are fish i don’t want to lose and can’t find a positive ID on what this mark is. Any advice? Thank you for helping in advance.