Captive oscars may be fed prepared fish food designed for large carnivorous fish. They can also eat crayfish, worms, and insects. Insects include, crickets, mealworms, grasshoppers, praying mantis and even hornworms. At about 6 months age, oscars can be fed live feeder fish, such as minnows, small gold fish and other feeder fish that can fit easily in their mouths. Captive bred oscars do best when fed natural frozen “carnivorous” fish food, along with live insects and crickets to keep a varied diet. These include, frozen bloodworms, frozen mysis shrimp, frozen beef heart, and frozen mixed fish cubes, as well as live feeders stated above. 