As some of you know I breed guppies as a little hobby. Last night my guppy had about 50 fry, some of them appear to have a chest that is protruding (it's really hard to explain, but it kind of looks like there chest is a giant bubble and is pushing out... or like a beer belly) They were like this before there first feeding, so it wasn't that they ate too much. By chance is this the symptom of a disease? Or what else could it be?