I would try to close its mouth too, but it is only about 1 1/4 inches long. I am a big guy and don't have a very gentle touch. I am afraid that the jaw might be broken already and don't want to cause the fish anymore pain.
29g tank with 7 tiger barbs and 1 red tailed shark
Temp is around 75 degrees
I don't know the nitrite, nitrate and ammonia readings, I don't have a
test kit. The tank has been up and running for a few months. The fish don't show any signs of stress or illness. In fact, ever since I put my shark in there her color has improved greatly compared to when she was in the 10g. The barbs are brightly colored as well.
I change about 5 gallons of water a week.