I have a friend who got a Betta as a pet for her child. It's in a little 1-2L container with a small light. I know it's not the best, but that's beyond my control. (I would put a heater and an aerator in there.) I'm comfortable looking after Bettas myself, but I know from my own experience that sometimes they are prone to diseases from water quality and from low temps. She wants advice, and I want to keep it alive. I'm checking on feeding and water changes. Question at hand: The fish has gotten that unusual teardrop shape that I see Bettas sometimes get (see attached sketch). It used to be more fish-shaped but now its belly bulges more, while its caudal peduncle (tail area) has gotten thinner. It was not me that noticed this, it was my friend, so it's enough for her to notice a change. It is not bulging appreciably, I've had Bettas that bulge. It is a *smooth* bulge, so not a tapeworm. I'm just not sure if this is normal or if this is the onset of disease (bloating). As far as I can tell, It does NOT have dropsy (i.e. pineconing scales). Otherise, it looks quite healthy: active, alert, erect fins, eating. Could this be simply over- or under-feeding? What think? Am I borrowing trouble?