A sea turtle spends nearly its entire life in the water. First, there’s that mad dash across the beach after the young sea turtle hatches. An adult female will come ashore to lay eggs later in her life. But the rest of a turtle’s life is in the ocean, where it uses strong paddle-like flippers to propel itself through the water.

So what’s with that claw on the front flipper?

loggerhead sea turtle
This loggerhead sea turtle's claw is digging into the sand.

For the answer, we turned to Charles J. Innis, VMD, the Aquarium’s chief veterinarian. He has lots of experience treating the sea turtles in the Giant Ocean Tank and the cold-stunned turtle patients rescued every winter. He reports that this claw is a remnant from when they evolved from earlier turtle species, but they may be used for different functions today. Males have longer, stronger nails than females. Adult males may use their claw to help grasp females during mating. Both sexes may use their claws to grip the seafloor as they crawl along underwater. Females may also use their claw as they move on beaches. 

So while sea turtles do use that claw on their front flipper, Dr. Innis also says that sea turtles also do just fine with no nails. For example, sometimes rescued sea turtles turn up with lots of injuries to their face and flippers. Those patients recover and make do just fine without those nails—huzzah! 

loggerhead sea turtle

So the next time you visit the Aquarium, take a close look at Myrtle, Carolina, and Retread in the Giant Ocean Tank. You can often get a good look at their flippers as the loggerheads rest at the bottom of the exhibit. See if you can spot the claw on their flippers, and then wow the folks you’re with by telling them all you know about these ancient appendages!