I bought a red zebra cichlid about a week ago and i noticed a few things: he has black spots on his gills, I haven't seen him poop once since i got him, its belly almost seems discolored, almost black looking. He acts and eats fine, and my water parameters are fine. I think he might either have a disease, or parasites. I'll try to get a pic of him, but he wont stay still. Any advise would be appreciated.