Ok so today I was in a rush home from work to check up on my little guy and to feed him. So ive pretty much spent the entire afternoon with him and I couldnt help but notice that he kept opening his mouth in his tank(Gaping), So i took him out for a bit and when he opened his mouth when I was carrying him I noticed a yellow area in the mouth and I really want to know if thats normal or no? I wish I could take him to the vet but Im caught up on bills at the moment. I will post a pic and possibly a video so you guys can tell me what you think. In the video you'll notice that there is like a quick popping sound when he opens his mouth. It doesnt always happen but I noticed it quite a bit today. He also spends alot more time now with this mouth open than before and he keeps scratching his head up against anything he can rub(finger, branch, or glass) Please give me some inputs on what could this be.