Retinal anatomy of hatchling sea turtles: Anatomical specializations and behavioral correlates

The eyes of three species of sea turtle hatchlings (loggerheads, green turt les, and leatherbacks) possess visual streaks, areas of densely packed gang lion cells running along the antero-posterior retinal axis. These probably function to provide heightened visual acuity along the horizon. The vertica l extent and absolute concentration of cells within the streak, compared to the rest of the retina, differ among the species. Leatherbacks have an add itional specialized region (area temporalis) that might enhance their abili ty to detect prey below them in the water column. Green turtles and loggerh eads, but not leatherbacks, show compensatory eye reflexes that keep the vi sual streak horizontal. Species differences in retinal structure and eye re flexes probably reflect their unique specializations in visual ecology and behaviour.