Posted on other forum but title change asking for help identifying marks on fish

[KarenLR75]

We introduced both fish (White Tail Bristletooth tang & Blue Throat Trigger) to tank at same time a few weeks ago. Tang is 4.5" long and trigger is 3".

The only aggression we've seen (I work remotely so I'm next to tank a lot) is at feeding time, the tang plays some passive aggressive games with the trigger usually centered around competing for pecking at pellets.

The tang would pin trigger in his cave and bump him. We tried ensuring pellets were spread over bigger range & we put pellets in when they were apart from each other at different sides of tank. Also, for several days we just fed mysis & saw big reduction in feeding aggression. Whenever we weren't feeding they swam by each other & next to each other without signs of aggression.

Flash forward to now and we've noticed tang SEEMS to be trying to takeover trigger's cave. Unsure why tang wants it when there is more 'hiding space' in the back of the rocks, but the tang can turn around in it BARELY. At first I thought the tang kept trying to get in there to get any remaining algae as our algae that he loves to peck at has been drastically reduced.

We noticed just yesterday though, a mark on trigger that looks like someone bit at his side and today the tang's eye looks...filmy/roughed up? My 1st thought is they got in a fight. 2nd thought was wondering if tang has some sort of illness/parasite, etc. but one thing we cannot deny is trigger surely seems it was in a fight with someone and as he's 2nd biggest fish in the tank, my guess is going to be with the tang?

I'll post pics of both. We'll be adding some additional caves/rock to rock structure today. We have 20 gallon tank we just bought for QT that we can setup although I'm unsure who needs to be QT'd. After reading HUGE thread on ICH and other things...I'm unclear as to whether it's more stressful to a fish to be in QT and when risks are outweighed by benefits.

Any input on the tang's pic in particular is appreciated. Unsure if we're dealing with battle wounds or an infection/parasite.

Help is GREATLY appreciated!

[JUNBUG361]

How big is your display tank? Both are some what aggressive. Not sure if they will get along

[KarenLR75]

My apologies. I forgot to post it. It's a 6 foot long 112 gallon tank with a 30+ gallon refugium. We waited to add our semi-aggressive fish until the end and these 2 were our final choices. The bristletooth were reputed to be easier than the tangs we had over 2 decades ago.

Had 3 different types for 5 years but were also clueless that having 3 different tangs in a 'then 50 gallon tank' was crazy.

[Hal]

Sorry, I can't help you with the diagnosis of your fish. However, i can suggest that if you re arrange the rocks it will often cause the fish to restart their claiming of territory. Maybe the trigger will pick a new spot that the tang isn't interested in.

Also, you can put your tank stats in your signature line, which will help,for many questions.