Hi,
I got a new puffer about 2 weeks ago. The thing was really skinny. So I started to fatten the fish up. Fish is all happy and healthy right now. But just the other day I was really watching and examining the fish. And I noticed on one side of the fish there is a darker area on the skin, and the area is sorta concave. This is located on the fishes side near the stomach. I'm not sure if its a birth defect, a scar from a previous injury or what. Does this description sound like anything that I should be concerned about? Fish acts healthy and happy, eats normally, poops fine, water conditions are great, regular waterchanges etc.
Here is a picture of the area, sorry for the poor quality of the picture:

I got a new puffer about 2 weeks ago. The thing was really skinny. So I started to fatten the fish up. Fish is all happy and healthy right now. But just the other day I was really watching and examining the fish. And I noticed on one side of the fish there is a darker area on the skin, and the area is sorta concave. This is located on the fishes side near the stomach. I'm not sure if its a birth defect, a scar from a previous injury or what. Does this description sound like anything that I should be concerned about? Fish acts healthy and happy, eats normally, poops fine, water conditions are great, regular waterchanges etc.
Here is a picture of the area, sorry for the poor quality of the picture:
