I feed my Oscars daily, as well as my sissy tetra tank, but every Sunday is fasting day for my Africans. A day of fasting now and then is good for them.
They dont NEED to eat everyday, but I think they prefer it. I feed mine everyday even if its a small portion because in nature fish are constantly in search of food.
i usually feed my fish every day...but lately my toga hasnt been eating...however he's started eating again... 6-7 block of bloodworm and insects haha costs me a fortune!