How often do you change your water, and how much?
Do you have a test kit? Can you get us the levels of the water chemistry?
What else is in the tank?
Live worms can carry bacteria and disease, and this looks like an internal bacterial infection known commonly as 'bloat'.
Check out the disease section of the forum for some tips posted by Oddball on how to cure this.
This could also be due to a sudden change in the water temperature. What is your temp at right now?
My buddy John swears by increased temps and adding salt to the water.
Do you have a test kit? Can you get us the levels of the water chemistry?
What else is in the tank?
Live worms can carry bacteria and disease, and this looks like an internal bacterial infection known commonly as 'bloat'.
Check out the disease section of the forum for some tips posted by Oddball on how to cure this.
This could also be due to a sudden change in the water temperature. What is your temp at right now?
My buddy John swears by increased temps and adding salt to the water.