Fat vs Skinny Mandarin

[Altohombre]

How do you figure out if your mandarin is skinny or fat? I feel like my mandarin is actively looking for food and seems pretty happy. At night I see small pod like bugs crawling around and such and I also supplement my tank feeding with Arctic Pods which my other fish go crazy for. My tank is almost 8 months old and full of life. I just can't tell whether my little guy is starving or thriving. I would say that the top half of his body is somewhat plump but it's hard to say because they have that weird head shape. Is a mandarin only fat when it is plump all the way to it's tail fin?

 

[yote]

Does its belly look like its caved in?

 

[daugherty]

if the belly is not caved in than it is healthy

 

[Altohombre]

I don't think so. It's hard to tell because it is mostly on top of things like rocks rather than floating in the water. Do you guys know of any images on the net that I can look at?