Okay for almost a week my two red zebras haven't been eating. They are in a 55 gallon tank with 3 scolofi, 4 yellow labs, and another larger red zebra. They just don't want to eat. When I feed them they do sort of come to the surface and will take in the food but they just spit it back out again. I haven't noticed any strange behavior besides that. No heavy breathing. No stringy feeces. Thier bellies are still green with sprinula. Any ideas?