Adaptations help hatchlings survive

By Aubry Forsyth

Sea turtle hatchlings face many obstacles on their journey to the sea. However, hatchlings have some adaptations that increase their chances for survival.

One of the most noted adaptations is in their eyes. Hatchling loggerheads, leatherbacks, and green sea turtles have retinal streaks, which help to provide visual acuity to look toward the horizon. This helps guide them to the ocean after emerging from their nest. The retinal streaks are made up of densely packed ganglion cells. Retinal ganglion cells process light entering the eye and send the information to the brain. They allow the hatchling turtle to see while out of water so that they can attempt to escape to sea. The retinal streaks fade away after a while and do not stay with the turtle into their juvenile years as they are no longer needed. Their eyes are also specially adapted to see in bright waters. They have curved lenses that refract light so that they can see clearly underwater. 

Sea turtles have other adaptations to help them survive. They have long, paddle-like flippers that hatchlings use to propel themselves through the water as quickly as possible. Their back two flippers act as rudders and help the turtles steer. Sea turtles have bodies that are flat and streamlined, making them hydrodynamic. This allows them to easily maneuver through their aquatic habitats. 

Some sea turtle species, such as loggerheads, use camouflage to their advantage. Loggerhead hatchlings swim to the Atlantic Ocean and out to the Sargasso Sea. The Sargasso Sea is named after the sargassum seaweed that floats there. There, hatchlings use the sargassum to blend in and hide from predators such as fish, seabirds, and sharks. They forage for food in the rafts of seaweed, where their prey is often plentiful. The turtles feed on small animals throughout their early years. Hatchlings also hang around in the sargassum to keep warm. The seaweed acts as a blanket and traps heat from the sun near the surface of the ocean. Because sea turtles are reptiles, they are cold-blooded and rely on sources of heat, like the sun, to stay alive. When the turtles are in warmer water, their metabolism operates faster, causing the hatchlings to eat more. This can lead to faster growth of the turtles. 

For more information on sea turtles and their adaptations, visit this website: https://ocean.si.edu/ocean-life/reptiles/sea-turtles