Comparative studies of retinal design among sea turtles: Histological and behavioral correlates of the visual streak

We understand very little about the relationships between eye anatomy and visual ecology in sea turtles. Sea turtles use visual information in important contexts, such as selecting habitats, detecting predators, or locating mates or food. This study represents an effort to clarify the form/function relationship between retinal morphology and the behavioral ecology of sea turtle hatchlings. Thus, it is an important first step in relating sea turtle eye anatomy with visual ecology and relating the two to sea turtle natural history. Some organisms possess retinas that contain morphologically specialized cellular areas. The "visual streak," is one such area; receptor cells and associated interneurons are concentrated in a horizontal band in the retina. Three species of sea turtles (Chelonia mydas, Caretta caretta, and Dermochelys coriacea) possess a visual streak located along the horizontal mid-line of the retina, although they differed in streak development. The differences in streak development can be related to their ecology.