What is on this bluethroat trigger face?

[fixingstill]

He was fine this morning. Then suddenly this shows up:

Looks like discoloration but it is hard to tell as he is so shy and hard to take good pics.

 

[SAT]

Can you give some history for this trigger? How long have you had him? Have you added any other (unquarantined) fish lately? I see you have an angel... what else is in the tank?

On the theory it might be from a trauma, do you have anything like an anemone that might have stung hum? Is he getting along OK with the other fish? Has he been scratching on something?

Unless you can identify a physical cause, you should plan to get him into a treatment tank.

 

[scooter31707]

I'll let the experts chime in, but IMO that maybe HLLE or some type of bacteria infection. May also be a case Brook.

 

[SAT]

It does resemble Brook. In my experience, HLLE manifests much more slowly.

 

[fixingstill]

Ok. He just got moved from the QT (6 weeks plus there) to my DT. It was day 2. It did have popeye infection when he was in QT but was cured by Kanaplex. Yesterday morning it was fine, then in the afternoon, he has that. I actually also asked Bob Fenner (wetwebmedia.com and author of the book Triggerfishes in Marine Aquariums) and he thought he was "burn" by bristle worm. I do have a lot of bristle worm (crawling around in broad daylight). This morning (day 2) the "burn" seems to be fading away. I guess this trigger has learned the lesson. He is ok now - I saw him swimming around at night. Thanks and really appreciate Bob Fenner answering me the question.