I know he's old. But, our 26 year-old buttekoferi is not eating. He otherwise seems healthy and active. He still shows plenty of signs of aggression (I cleaned his tank yesterday and was actively attacking me and the sponge). But he just lets cichlid pellets drop right in front of him. I tried worms and cichlid specialized bugs. He still doesn't eat. He doesn't have any fungus. Any suggestions would help--and i do realize he's very old.