Neon Color Ruled

Neon Color Ruled
Aquarium of the sick … neon tetra

I bought eight of these little over 8 months. ago. Trasition did not, but the rest have been all right, eating well and growing. Just noticed that one looks bad, the colors fade, and the lower jaw to his "lip /" is fully open. It seems that he can not shut his mouth, hanging just wide. But swimming well, but is having difficulty eating and can not close the jaw. Nothing slimy, which excludes "ick." I'm not really too much for him and does not intend to do anything unless there is something to kill my other fish (I have classes to others are doing well). Tank is healthy. Any ideas? Nothing new has been there recently, so there is possibility of a new fish or plant is the culprit.

I would suggest that fish out of the tank and put it in its own sepret of 1! It is possible that it could make all the other fish too sick to Take Out as before! I hope he got better!