The marine animal in the picture may be described using a wide variety of adjectives: beautiful, strange, cute, and fantastic. It could also be called a science fiction monster, a Photoshop trick, a Mythical Pokémon, or some sort of avatar… you name it!
It’s a nudibranch commonly known as “blue dragon” or “sea swallow”. It’s a soft-bodied pelagic mollusk, a relative of snails and slugs. Its scientific name is Glaucus atlanticus. Blue dragons are small (about 4-5 cm), pelagic, they drift upside down on the surface of the ocean, they are hermaphrodites, and perhaps most importantly, they are highly poisonous.
Blue dragons feed on other pelagic sea creatures such as the venomous Physalia physalis, also known as the "Portuguese Man-Of-War". They eat the stinging, venom-filled tentacles of Physalia and concentrate the venom in the tip of the dark-blue finger-like branches at the end of its six appendages. This protects them from other marine predators.
Glaucus atlanticus, also known as Blue Dragon or Sea Swallow is a relative of the snails and slugs.
The fanciful critters are widely distributed in the world’s oceans. They prefer temperate and tropical seas. They can be found in the Pacific and Indian Oceans, the shores of Africa, Mozambique, the east coast of Australia, and many locations in the Atlantic Ocean including the coasts of Brazil, Uruguay and Argentina.
Glaucus atlanticus was first described in 1777 by German zoologist Georg Forster who found it in the Pacific Ocean while travelling in “HMS Resolution” in Captain James Cook’s second trip to the Pacific (1772–1775).
The pictures included in this blog about this odd-looking, but amazingly beautiful sea animal, were kindly provided to me by Jason Shelley. Jason found several blue dragons washed up on Marley Beach in Royal National Park, near Sydney, Australia. He placed them into a tidal pool to see it they could recover. Jason said that within 10 minutes they seemed to recover and started moving.
The video below was captured in Uruguay (Maritrillo87).
What do you think? Aren’t they beautiful?