In the green one-celled organism Euglena, the eyespot is located in the gullet, at the base of the flagellum (a whiplike locomotory structure). A cup-shaped mass of pigment rods shields a sensitive area of the flagellar base from light coming from the direction of the opposite end of the organism.

What organisms have eyespots?

Eyespots, or ocelli, are eye-like markings found in a diversity of organisms including lepidopterans (butterflies, moths, and skippers), reptiles, fish, birds, and cats.

Why do euglena have eyespots?

Euglena also have an eyespot at the anterior end that detects light, it can be seen near the reservoir. This helps the euglena find bright areas to gather sunlight to make their food. Color and label the eyespot red.