What Are Those Blue, Winged Creatures Washing Up On South Texas Beaches?

The blue dragon looks like something out of “Harry Potter,” but it’s really a sea slug – one that stings.

By Michael MarksMay 20, 2020 9:30 am

Beauty is in the eye of the beholder, they say, but it’s tough to argue that some animals are just more beautiful than others. The sea slug, for example, is an invertebrate that many might rank fairly low, aesthetically speaking. But perhaps that reaction needs to be reconsidered, given how a particular species recently caught the eye of Texas beachcombers.

The sea slug in question doesn’t look anything like a slug.

“It kind of makes me think of, like a dragonfly,” said Jamie Kennedy, a park ranger at Padre Island National Seashore.

Kennedy is talking about a slug called glaucus atlanticus – better known as the blue dragon. They’re remarkable-looking – like something you’d find in “Harry Potter” or “Pokemon,” rather than the Atlantic.

“You know they really do look kind of like dragons. It’s a very pretty bluish, kinda silvery with a little bit of white or grey on it. And then it has two sets of wings almost, I would say,” Kennedy said.

Blue dragons are just a few centimeters long at most, but they eat one of the most feared creatures of the sea: the Portugese man-of-war – a jellyfish-like invertebrate known for its powerful sting. The sting is typically a repellent, but that’s the draw for the blue dragon. They chomp off parts of a man-of-war’s tentacles and store the stinging cells in their wings.

“So they’re basically preying on the Portugese man-of-war and then stealing their stinging power and then putting it at the tips of their fingers so they can use that as their own protection,” Kennedy said.

Kennedy knows a lot about these slugs, especially for someone who’s never actually seen one. Blue dragons are a rare find. They blend in with the water, are only occasionally found washed up on shore.That’s why what happened at Padre Island earlier this month was so unusual.

“This is the first time in over two years that I’ve heard of anyone seeing them or finding them,” Kennedy said.

In early May, a family who didn’t know what they’d found sent a photo to Padre Island National Seashore of a blue dragon in a green bucket, asking what it was. Kennedy posted it to the park’s Facebook page.

“We got a ton of comments on the Facebook post saying other people had found them in the park or nearby the park, and lots of pictures of them, so definitely a lot of them were washing up that weekend,” Kennedy said.

It’s not exactly clear why. Blue dragons use an internal air bubble to stay afloat and they move by bobbing around with the wind and tide. So Kennedy thinks that maybe some blue dragons were born nearby, and then were all pushed ashore by the same current – a coincidence like a meteor shower..

“It’s rare, right? There were dragons in the park, and they’re pretty rare, and now they’re gone,” Kennedy said.

Still, if you’re on the coast this summer, keep an eye out for dragons, but keep your hands to yourself. Seeing something so rare is unforgettable enough – no need to add getting stung to the experience.


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