I have 6 discus and this specific one is actually a bit bigger than the others but it seems as though it's belly may be sunken in. Its not as vigorous as the others and it eats but not nearly as crazy or fast as the others. Definitely about a 1/2-1 inch bigger then the others not sure what other description I can give but I can post a picture with all of the to compare.
I am worried as the other 5 actually have puffier stomach/chests.
Just wondering if anyone can think of possible issues it could have with a stomach like this and what I could maybe do. Or if it seems normal.