Sea Turtles Use Flippers For Handling Prey
Many have thought that sea turtles use their flippers for locomotion only. But an amazing discovery is making headlines just recently and it took researchers by surprise.
A team of Monterey Bay Aquarium researchers discovered that sea turtles use their flippers to manipulate food as well, not a common trait among marine tetrapods. Despite having limbs being evolutionarily designed for locomotion, sea turtles use their flippers to handle prey.
The amazing thing that struck the researchers was that this behaviour is actually widespread among marine tetrapods and may have been occurring 70 million years earlier than previously thought.
This discovery was confirmed by Van Houtan, Director of Science at Monterey Bay Aquarium and one of the authors of the research.
Van Houtan said, “Sea turtles don’t have a developed frontal cortex, independent articulating digits or any social learning. And yet here we have them ‘licking their fingers’ just like a kid who does have all those tools. It shows an important aspect of evolution – that opportunities can shape adaptations.”
The study was led by Jessica Fujii who specializes in ecomorphology – the intersection of evolution, behavior and body form.
Fuji’s expertise in sea otter foraging and tool use behavior has influenced her to probe how sea creatures have evolved to use their limbs in novel ways.
Using crowd-sourced photos and videos, Fujii and Van Houtan discovered widespread examples of behaviors such as a green sea turtle holding a jelly, a loggerhead rolling a scallop on the seafloor and a hawksbill pushing against a reef for leverage to rip an anemone loose. These behaviors have been observed and documented in marine mammals from walruses to seals to manatees – but not in sea turtles. The researcher concluded that sea turtles are similar to the other groups in that flippers are used for a variety of foraging tasks (holding, bracing, corralling).
“Sea turtles’ limbs have evolved mostly for locomotion, not for manipulating prey,” Fujii says. “But that they’re doing it anyway suggests that, even if it’s not the most efficient or effective way, it’s better than not using them at all.”
Aside from that, the key findings also offer an insight into the evolution of four-limbed ocean creatures that raises questions about which traits are learned and which are hardwired.
“We expect these things to happen with a highly intelligent, adaptive social animal,” Van Houtan says. “With sea turtles, it’s different; they never meet their parents,” Kyle says. “They’re never trained to forage by their mom. It’s amazing that they’re figuring out how to do this without any apprenticing, and with flippers that aren’t well adapted for these tasks.”