Red Danio with a large belly

Question

Red Danio with a large   Hi there,
My fish has a abnormal large belly,is it a pathological condition or is it just its way,First I thought it was pregnant but its been there for almost 4 months. It has a normal appetite and swims normally, but some times I find it resting among the plants at the bottom.Please refer the attachment for the Picture.
Thank you.

Answer
Numark,
It looks like swim bladder disease. Fast the fish for 2 days, and on the third day feed it a cooked shelled pea and then fast again for 2 days. This can happen if a fish is over fed and then it get blocked up. The pea should clear it up. If it doesn't in a few days fast again and feed the pea.