Definition: Apodemata, in zoology and botany, refers to a group of animals that are characterized by a single, large eye. These animals have no eyes but instead have compound eyes (two pairs of eyes) arranged around a central organ called an ocellar. The eyes are often surrounded by a complex network of muscles and nerves that control the movement of these organs. Apodemata include many different groups such as fish, snails, crabs, lobsters, octopuses,