My adult sajica's mouth rapidly swelled in two days and now it became stiff and protruded. It looks like there is a thin orange layer in the jaw. What can be the reason for this? How can I help it? It hasnt fought or jaw-locked recently.
Can you tell us more? What size tank, what other fish, how long the tank has been set up, what your water parameters are, and how you maintain the tank? There's a thread at the top of the forum that explains what information we need in order to help you.