Bicolor angel-mouth always open

[aagancia]

[aagancia]

[Clam Guy]

Poor you. 30 views and no reply.

Did you test your water? Ammonia, Nitrate, Phosphate, pH, Temp, Nitrite, Salinity, etc... Perhaps something is out of whack, but if all the other livestock appear to be fine, then maybe your angel has an internal parasite. I'm suspecting this as it has bloated stomach as you say. Can't really be sure.

If something is off in your water paremeters, correct as necessary, usually by a water change and or dosing of necessary additives. If nothing is wrong with your water paremeters, perhaps hospitalise the angel in a separate tank, and treat it with medicine that kills internal parasites, or create hyposalinity in the hospital tank.

And if you want to use copper read below.
This is from Wetwebmedia:

Some Centropyge angels are notably sensitive to copper medications... and some authors therefore proscribe the use of alternative therapies and therapeutic agents (e.g. formalin). If you use copper, I would make this a chelated format, with matching daily testing, and keep the therapeutic dose/concentration on the lower end (0.15-0.20 ppm of free cupric ion).

Good luck!

[aagancia]

[Clam Guy]