I've posted this already and no one wrote anything so I'm going to try again. My beloved gold Dat Marty is not eating. He has always eaten shrimp, silver sides, and cut white fish. He had feeder minnows but so did the other two dats and several bichirs and that was months ago. There is no gravel in the tank. He still desperately goes after the food but mouths it and spits it out. Any idea what could be causing this? Parasite, blockage, internal damage? Any ideas would be helpful please post anything that comes to mind.