Bizarre "Blue Dragon" Sea Slugs Are Washing Up On Texas Coastlines

The bizarre but beautiful blue dragon is actually a kind of sea slug. Wkimedia

Rachael Funnell 12 May 2020, 17:00

They might look like aliens, but these bizarre marine animals are actually a type of nudibranch, also known as sea slugs. Usually found bobbing along in the open ocean, a park on the Texas coastline has reported that there has been an unusual surge in sightings of these habitual drifters. In response to the apparently blue dragon bloom, the Padre Island National Seashore park is urging visitors to approach them with care as the resourceful digestion process of these stinging nudibranchs makes them a danger to curious hands.

The Padre Island National Seashore (PINS) preserves the longest undeveloped barrier island in the world, situated in the Coastal Bend area of southern Texas. Protected by the government, it’s home to numerous rare, threatened, and endangered species. While blue dragons are not unheard of on the park’s shores, according to PINS officials they are a rare find, and sightings of the bizarre tiny blue sea slugs have been on the rise.

Glaucus atlanticus, also known as blue dragons or, our personal favorite, “the dragon slug”, are an unusual species of nudibranch whose threat level increases based on their recent dietary habits. Partial to the deadly Portuguese man-o-war jellyfish, as well as other venomous siphonophores, the vibrant sea slugs are able to retain the stinging nematocysts from their meal and deploy them along their “fingers” which they use when hunting. For this reason, the sting of a blue dragon can actually be as severe as that of a Portuguese man-o-war, proving very painful and even dangerous to humans despite their small size (3 centimeters). Common symptoms include nausea, pain, and vomiting as well as localized swelling and a rash.


They usually drift out in the open ocean, bobbing along upside-down on the water’s surface using their coloration as a form of countershading. The deeper blue side sits on the surface allowing the sea slugs to blend in with the ocean from above while the silvery side points to the seafloor, eliminating its silhouette against the daylight shining down.

“If you see a dragon in the park, be amazed as they are a rare find,” said PINS in a Facebook post, “But also keep your distance!”


If you liked this story, you'll love these

This website uses cookies

This website uses cookies to improve user experience. By continuing to use our website you consent to all cookies in accordance with our cookie policy.