Watch: Sea Turtle Snacks on Jellyfish Tentacles

A young green sea turtle snaps up a stinging meal.

Humans aren’t the only animals to like their meals with a little bite—or a little sting, as the case may be.

In this video, shot by marine biologist Johnny Gaskell, a young green sea turtle munches on a jellyfish in the shallow waters around Hook Island, Queensland, in Australia’s famous Great Barrier Reef. Though almost all of the world’s seven species of sea turtles are omnivorous—meaning they eat pretty much anything, including jellyfish—green sea turtles are mostly herbivorous as adults.

The turtle in this video is a juvenile, likely between 2 and 5 years old, at a stage in its development where a more omnivorous diet is typical.

SEE A SEA TURTLE DEVOUR A JELLYFISH LIKE SPAGHETTI

THE GREAT BARRIER REEF

A diver swims above a garden of stony corals on the Great Barrier Reef, which is more than 1,250 miles long. Climate change poses a multitude of threats to this international treasure.
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An anemonefish peers from its home in the Great Barrier Reef. As fossil fuel emissions get taken up by the ocean, they can change its chemistry, which can alter how tropical fish see, hear, smell, and avoid predators.
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Cardinalfish zip by a loggerhead turtle as it rests among feathery invertebrates called hydroids. As marine waters warm, they can lead to more bleaching events on reefs, reducing hiding spots and sources of food.
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Currents in Challenger Bay push and pull a school of diagonal-banded sweetlips. Rising seas and warming oceans can change the reef’s ability to block storm surges.
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A bumphead parrotfish and a grouper hover near the sandy bottom.
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The clownish grin of a bridled parrotfish reveals its power tools: grinding teeth used to scrape away algae, a mostly beneficial move. As more CO2 enters the sea, it can cause drive the growth of more algae, which threatens to smother more of the reef.
PHOTOGRAPH B Y DAVID DOUBILET, NATIONAL GEOGRAPHIC CREATIVE

Moray eels battle for a hiding spot in Challenger Bay. As oceans sour from absorbing more CO2, some corals struggle to grow, which can reduce hiding spots for a variety of marine creatures.
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A two-foot-long sea cucumber, kin to sea stars, shoots thousands of ova into the current to spawn en masse.
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A scuba diver hovers above a black coral tree bursting with cardinal fish. Divers travel from around the world to dive on the Great Barrier Reef, an economic boon to Australia that is threatened by climate change.
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The humphead wrasse is among the reef's many thousands of species.
PHOTOGRAPH BY DAVID DOUBILET, NATIONAL GEOGRAPHIC CREATIVE

The Great Barrier Reef is among the most diverse marine environments in the world, hosting 5,000 types of mollusks, 1,800 species of fish, and 125 kinds of sharks. Much of this diversity is threatened by warming seas and ocean acidification.
PHOTOGRAPH BY DAVID DOUBILET, NATIONAL GEOGRAPHIC CREATIVE

“What's interesting here is that it's actually going for the [jellyfish’s] tentacles and not the bell, which would maybe have more nutrition,” says David Gruber, a marine biologist and National Geographic Explorer.

A jellyfish’s tentacles do seem to be an odd choice of meal: humans are wary of their sting, which occurs when skin contact triggers small, harpoon-like structures called nematocysts to inject venoms that attack the victim’s cells. (Read about a microscopic nematocyst arms race.)

But because sea turtles are reptiles (and therefore scaly), they’re much less vulnerable to these nematocysts. This turtle’s only sensitive spot is its eyes, which it protects by closing its eyelids and shielding itself with a flipper. And it seems to suffer no ill effects from ingesting the tentacles, Gruber says.

Such an iron stomach at such a young age can only be an advantage: green sea turtles can grow to weigh up to 700 pounds and live about 80 years in the wild.

Though jellyfish are certainly on the menu for juvenile green sea turtles, it’s possible “to hypothesize that the sea grass the turtle would normally eat has been disappearing, and now it's going for these lower-grade diets,” says Gruber.

In recent years, the Great Barrier Reef has suffered drastic coral bleaching as a result of global warming. Sea turtles—all species of which are listed as endangered—are vulnerable to such changes in their native ecosystems. They also face the threats of being killed deliberately, for their meat and eggs, or accidentally, when struck by boat propellers or entangled in fishing nets until they drown. (Read "This Turtle Tourist Center Also Raises Endangered Turtles for Meat")

As for the young turtle’s victim: if the jellyfish isn’t torn to shreds, there’s a chance it may survive to regrow its lost tentacles.

Though the individual in this video bears a strong resemblance to the lion’s mane jellyfish (Cyanea capillata) found in the cold waters of the Arctic and northern Atlantic oceans, it’s likely a member of a related species, differentiated by the red stripes around the base of its bell and its Australian habitat.

Both species often enjoy symbiotic relationships with small fish, like the butterfish seen in this video, which eat the jellyfish’s leftovers in return for protection from predators.

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