While goldfish are scavengers and generally eat any type of fish food, their dietary needs consist of less carbohydrates and protein than tropical food provides. Fish food made specifically for goldfish comes in either flake or pellet form.
The type of goldfish food needed depends primarily on the size of the fish. Smaller goldfish typically cannot eat pellets due to the size. While goldfish in captivity are generally fed specific goldfish food, wild species often eat insects and plants and sometimes even other fish. In captivity, they can also eat shelled peas, brine shrimp and bloodworms, along with pellets or flakes.