Bump on Flame Tetra

[Chopweiler]

This afternoon I noticed a bump on the bottom of my flame tetra that had never been there before does anyone know what it could be?

 

[Colin_T]

It looks like its intestines has pushed out its butt.

It normally goes back in by itself but if it hasn't after a day, you can carefully catch the fish in a net and keep it in the water. Then very gently run your finger along the underside of the body. Do this a couple of times and it might help. But be very careful because you can damage the fish if you are rough.