Rare Venomous 'Blue Dragon' Sea Slug Found on Texas Beach

A rare and potentially dangerous "blue dragon" sea slug has been found on a beach in Texas.

Footage showing the tiny creature was taken by Erick Yanta. In the video, Yanta can be seen holding a clump of sand with a small, blue and white animal perched on top of it.

Yanta posted the clip to Reddit asking for help identifying the creature. Dozens responded saying it was a type of sea slug—or nudibranch. These are shell-less marine molluscs that are often extremely brightly colored. Many species of nudibranch have the ability to steal venom from their prey.

Glaucus atlanticus, the species Yanta appeared to have found, is known to eat Portuguese man o' war—a type of siphonophore, which are creatures closely related to jellyfish. These animals have extremely potent venom they use to paralyze and kill their prey. While their stings are not normally fatal, they are excruciatingly painful.

Glaucus atlanticus
Stock image of Glaucus atlanticus. A blue sea dragon was found on a beach in Texas. Getty Images

Glaucus atlanticus, also known as blue sea dragons, are able to store the stinging cysts from Portuguese man o' war and other venomous organisms within their own cells. They can then use it as its own defense, including against humans.

Yanta was with his family on a beach around 18 miles south of Port Aransas when he spotted the sea dragon. "My family and I were watching and running in the waves rolling back and forth on the beach, looking at seashells," he told Newsweek. "My wife saw a bright blue shape on the sand and pointed it out, when we got closer we saw it looked like a creature of some kind. I scooped up the sand under it to lift it up, not so much because I assumed it was dangerous but because it looked so small and fragile.

"After I lifted it up and saw it was alive and looking around at me, we grabbed a cell phone to get a video of it to figure out what it was later on in the day. Then I walked out in the water and let it go."

Glaucus atlanticus
Stock image of Glaucus atlanticus. After filming the sea dragon, Erick Yanta put the little creature back into the ocean. Getty Images

Portuguese man o' war are known to get washed up on Texas beaches in spring and late summer. Glaucus atlanticus tend to live out in the open sea, traveling close to their prey. In 2020, sea dragons started washing up on the Padre Island National Seashore, which is about 50 miles south of Port Aransas.

At the time, David Hicks, a professor at the University of Texas Rio Grande Valley (UTRGV) said that every so often, a pocket of water gets dragged into a current and brought to the shore. "And if that water mass has this community of organisms in it, then it will bring them onto the shore," he said in a statement.

"Marvel at how pretty they are and maybe take a picture, but I wouldn't pick one up. Whenever the blue dragon consumes the Portuguese man o' war, it'll actually take some of those stinging cells and has sacks where it stores them on its own body. Now he's protected. Because if anything touches it, it will get stung, just as if it had touched the Portuguese man o' war."

Yanta said he was very glad he did not touch the sea dragon he found. "I laughed pretty hard after finding out just how dangerous these might be," he said.

Laura Jurgens, assistant professor in the Department of Marine Biology at Texas A&M University at Galveston, told Newsweek the sea slug Yanta found was most likely a Glaucus atlanticus, but that it was "not looking well."

"They are not unheard of in Texas waters but are fairly rarely washed up on beaches," she said. "They are one of the most beautiful animals in the sea."

This article has been updated to include quotes from Laura Jurgens.