I used to think that fish accepting food was a learned behavior...
I have been keeping adult keyholes over the past year and have tried them with a variety of foods. They love all frozen foods, flake, peas, fruit, but they have always been "meh" about cichlid pellets.
I just tried my 3 mo keyhole fry on the NLS mini cichlid pellets that their parents rejected. The juveniles try them, then spit them out. They are voracious eaters, but they have the same tastes as their parents.
Maybe "cichlid pellets" are designed for Africans. Anyone with SA cichlids that LOVE pellets?