My oto is very active and it's been like a month and he's survived. I noticed his stomach is small though...like smaller than when I first bought him. It's the shape of a white oval, but underneath, the bottom has disappeared kind of like if there's an air bubble/empty space. Did the stomach actually shrink? Will it grow back if he eats more? He's pretty much cleaned my tank from algae have some hard green algae but he won't touch that. But I see him poop every 5 minutes so he IS eating something.