I had a 16" red banjar that was a very aggressive eater he would jump out of the water & almost bite my fingers off for a worm, he would eat everyday & never refuse a meal. When I showed him food threw the glass he would go mental trying to bust threw the glass to get to it
then a I bought a 4 year old RTG 23" very fat fish but he is a very slow eater & likes to go days without eating, he turns his noes up at meals & will nudge food with his noes & then come back to it before he eats it.
he's still good to watch when he gets in a feeding frenzy but I think if he was in with a bunch of peacock bass he would end up starving