yes they can go a good few weeks with no food fine, even at that size. food wise its best to pellet train a aro as soon as possible you want to be persistent to do this, for best results stick with either hikari's cichlid gold range or there floating food sticks...
once you get the aro established on pellet you can vary its diet with blood worms, meal worms, earth worms, frozen prawns ext.... just pellet train it first and keep it feeding a high quality pellet as its staple diet.....