New Butterfly Fish Probably Sick...Need Help Diagnosing

[livinlifeinBKK]

Hi everyone, so I just recently set up a fowlr tank because as we all know, some of the most beautiful fish are corallivores. A few days ago I got a butterflyfish...sorry I can't quite think of the name right now but it's about 3 inches, has a vertical black stripe running from the top of his head down past his eye, and has a spot on his tail. He seems to be doing fine except for one weird thing-- his head twitches to one side sometimes like he has a "nervous tic". I'm thinking maybe something has infected his gills on one side but that's just my guess since I haven't seen this before. What do you guys think?

 

[vetteguy53081]

We need your help:
You never mentioned what type of butterfly as many have blck stripe,
we need clear pics under white light
Age of tank
Water parameters (ammonia-nitrate-ph-salinity-temperature)
What test kits are you using ?
How was fish acclimated and for how long ?

Twitching at times are trais are butterflies but constantly is not.