Goldfish trying to jump out of tank??

I have a blackmoor goldfish who lives in a 20 gallon tank. He appears happy and healthy and all of the water parameters are exactly where I want them, however, I find that he often darts to the top of the tank and breaks the surface of the water, and it looks like he is trying to jump out of the water. Should I be concerned or is this normal goldfish behavior? Thanks! I have also attached a picture of him in his tank as well.

It is not normal behavior for a goldfish. Have you tested your water parameters? Perhaps something is wrong with the water. They will also jump.if there is lack of oxygen due to dirty water. How often do you clean the tank? Goldfish are companion fish and he really should have a friend. However, you need at least a 29 gallon in order to do that. You need 20G for one fancy and 10G more for each additional one. For now,test your water. Be sure not to spray anything around the tank that could get in the water also.