Maize, also known as corn, is a tall annual grass that can grow to be 1.2–4 meters (4–13 feet) tall. It has a single stem with long, narrow leaves that grow alternately on opposite sides of the stalk. At the top of the stem is the tassel, which is an inflorescence of male flowers that release pollen when blown by the wind. The seeds of the maize plant are called ears, and they grow between the stem and the leaves to be about 20 centimeters long. Each ear contains many small seeds called kernels, which are usually white or yellow but can also be red, purple, or black.

Maize contains energy, protein, amino acids, minerals, and vitamins. It's used in fish diets, and is usually ground into meal or pellets.