Correction: This species is a dorid, not an aeolid. The appendage is a gill plume used for respiration—not a cerata. Unlike other mollusks, these colorful sea slugs don't have shells or gills. | National Geographic

The blue dragon, known as Glaucus atlanticus, is a sea slug that defends itself by converting its prey's venom into its own weapon. Measuring just about an inch, it floats atop the ocean where its silvery-blue color camouflages it from both above and below. Its primary meal is the Portuguese man owar, a creature with potent venomous tentacles. The blue dragon is immune to this venom and stores the stinging cells on its feather-like appendages, giving it a sting even more painful than that of its

"THE BLUE FLEET 💙 Glaucus atlanticus, Glaucillia marginata, Physalia utriculus, Porpita porpita, Velella velella & Janthina janthina. In other words Blue Dragons, Blue bottles, Blue Buttons, By-the-Wind Sailor & Violet snail. These beautiful blue creatures got swept onto Sydney's shoreline today. Which ones your favorite?" ~ snorkeldownunder 🎥 | Ocean Conservation Research - OCR