Emperor Angelfish has growth below his mouth

[timmyg]

What is this and what can I do to treat it?

Could it have came from a lionfish sting?

[CaptainAhab]

you should post this in the sick fish section

[timmyg]

What is this and what can I do to treat it?

Could it have came from a lionfish sting?

[melosu58]

Hard to tell from the pic but it could be a fungal problem.

[melosu58]

Both threads merged together.

[Innovator]

Looks to be a neoplasm, tumor. If this is the case there really isn't anything you can do other than surgery. By chance, what is the animal's diet? Do you feed any vitamin supplements? The other possibility is a bad case of lymphocyctis, but hard to tell from the pictures. Since you have a liofish, angels are notorious for biting their fins so it could be a wound within the mouth...