How are the eyes of fairy shrimp different from the eyes of tadpole shrimp?

The eyes of fairy shrimp (anostracans) and tadpole shrimp (notostracans) differ primarily in their physical placement and mobility. In fairy shrimp, the eyes are positioned on movable stalks, allowing for a greater range of motion. In contrast, the paired eyes of tadpole shrimp lie close together on the top of the head and are not stalked.1

Both types of branchiopods utilize their eyes for visual scanning, as all branchiopod eyes are equipped with muscles that facilitate rapid, trembling movements. These movements are believed to be a scanning process that provides the animal with more detailed information about its surroundings than a stationary eye could provide.1